Evaluation of a tool for rating popular diet books.

Introduction

The incidence of obesity is increasing worldwide (1). In 1999-2000 the AusDiab study estimated that 60% of Australians aged 25 years or more were overweight or obese, with significant increases over the past 20 years (2). Population surveys in Australia suggest that 55 to 68% of adults have tried to lose weight at some time, 37 to 47% attempt weight loss annually, and that at any particular time 20 to 24% will be making an effort to lose weight (3). There is also evidence that many adolescents attempt to lose weight by dieting. One study of Australian adolescents found that 22% reported they were trying to lose weight (4). Dieting is particularly common among females and books are one of the most popular sources of weight loss advice (5). The popularity of self-prescribed dieting means that it is important for weight loss diet books to provide nutritionally adequate advice and to provide scientifically accurate information.

A large number of diet books are published each year, and books are identified by Australians as one of the most useful sources of nutrition information (6). Some of the diet books are nutritionally sound, and offer advice on safe and effective weight loss, based on scientific evidence of efficacy and safety. Others, however, are questionable and may even be harmful to health. Some books contain a mixture of fact and fiction, while others rely on a 'special' combination of pills or powders, or have complicated lists of rules and regulations that must be followed. Food faddism refers to any dietary practice based on an exaggerated belief in the effects of nutrition on health and disease (7). There are a number of features often found in popular weight loss books that have been ascribed to fad diets in general (8). Simplistically they may:

* promote or ban a certain food or food group;

* imply that food can change body chemistry;

* blame certain hormones for weight control;

* recommend supplements or health foods for everyone; or

* promise quick, dramatic or miraculous results.

The best way to lose weight and maintain weight loss is simply to decrease energy intake and increase physical activity (9). Analysis of data from the US National Weight Control Registry, which keeps a record of people who have been successful at maintaining weight loss, shows that the people most likely to diet successfully are those that followed a diet that restricted energy intake, contained less than 30% energy from fat, and included regular physical activity (10). Fad diets that promise novel dietary approaches for rapid weight loss rarely have any scientific evidence to support long-term use (11).

However, the popularity of fad diets suggests that many people appear to be more concerned with achieving rapid weight loss than with the nutritional adequacy of the diet or the likely maintenance of long-term weight control (12). Rapid weight loss followed by rapid weight gain can have adverse effects on the metabolic rate, making it easier to gain weight in the future (13). At least one study has suggested that such variations in weight may constitute a health risk (14). In order to be able to respond appropriately to enquiries from the public, it is important for dietitians and other health professionals to be able to assess the reliability of popular diets and comment on them knowledgeably.

A number of reviews of popular diet books have been carried out (15-23). The general consensus has been that, while many can enable people to lose weight initially, some diets are nutritionally inadequate or recommend strategies which are not supported by current public health guidelines (24,25). While several authors have attempted to rate diets and give them a numerical score, they have not been explicit in the methods used, and there is no comprehensive quantitative system that can be used to evaluate new popular diet books. Such a tool would assist dietitians and other health professionals in their role of helping consumers to combat nutrition misinformation (26).

The aim of the present study was to develop a rating system that could be used by health professionals to evaluate popular diet books. A questionnaire was developed, incorporating quantified criteria, which was then tested for practicality, validity and sensitivity by evaluating 20 popular diet books available in Australia in 2001. Although some of the books promoted a variety of health benefits in addition to weight management, for the purposes of this study only the weight loss aspects of the diets were considered in the evaluations.

Methods

Part 1: Developing a method to assess the diets

A review of the literature was undertaken to identify methods that have been used by authors who have attempted to evaluate popular diet books in the past (15-24,27). In addition, statements from the Dietitians Association of Australia (DAA)(28-30), the American Dietetic Association (ADA) (31,32) and the National Health and Medical Research Council (NHMRC)(33,34) were consulted. From these sources, the following common criteria were identified to consider when assessing fad diets:

* Nutritional adequacy

* Promised rate of weight loss

* Energy content of the diet

* Macronutrient composition of the diet

* Use of special supplements

* Whether the diet can be followed comfortably on a long-term basis

* Physical activity recommendations

* Authors' educational qualifications

* Scientific evidence.

Quantitative targets were then established for each of these factors, incorporating national nutrition guidelines where available, and these were used to develop a set of 22 questions to assess the content of popular diet books.

The questionnaire is set out in full at the end. It was designed to give each book a rating out of 100, divided into various sections as described below.

1. Nutritional adequacy

This section is allotted 40 out of the total 100 marks. The first five questions, about the number of serves recommended per day from five food groups, are derived from recommendations in the Australian Guide to Healthy Eating (AGHE) for men and women aged 19 to 60 years (35). The next four questions on desirable macronutrient balance are based on authoritative recommendations about fat (36), carbohydrate (37) protein (25) and alcohol (38). They also reflect recommendations from DAA in relation to macronutrient balance in weight reduction diets (28).

The recommendation on protein (12 to 25%E) is somewhat tentative. The mean protein intake of Australian adults reported in the 1995 National Nutrition Survey was 17.1%E (39). There is mounting evidence that protein intakes in excess of two to three times the RDI--which equates to around 17 to 25%E--may be harmful (40). While there is one study that reported significantly greater weight loss from a diet providing 24%E in protein (41), there is no evidence of the long-term effectiveness of high protein diets and the target chosen is consistent with the current advice for weight management from the NHMRC (34). The final question in this section relates to the Better Health Commission's target to increase the dietary fibre content of the Australian diet to 30g per day (42).

2. Energy allowance and recommended rate of weight loss

This section is given a total of ten marks, with two questions, each worth five marks. The first question relates to the minimum daily energy prescription, while the second question concerns the promised rate of weight loss. A minimum daily energy intake of 1000 to 1200 Cal (4200 to 5000 kJ) is recommended for weight loss diets by the National Health and Medical Research Council's policy statement on slimming diets {33). This statement and others also recommend no more than half to one kilogram of weight loss per week (43). Books that prescribed energy intakes below 1000 Cal (4200 kJ) per day, or weight loss of greater than one kilogram per week lose marks in this section.

3. Flexibility and sustainability

This section is allocated a total of 15 marks. Three questions are asked, each related to an area that has been found to be important for long-term, successful weight control (15,16,23,44):

* inclusion of a wide variety of foods and allowance for individual preference and taste

* making permanent, realistic lifestyle changes

* making appropriate behavioural changes.

Those diets, which allow only a limited range of foods, are still given five marks for the first question in this section if they provide useful advice on aspects such as recipe modification. Diet books that include advice on supportive behavioural changes, such as ways to deal with stress and depression, or ways to break unwanted habits such as eating while watching television, are given a score of five for the third question.

4. Physical activity

This section contains two questions worth a total of ten marks. The questions are based on the National Physical Activity Guidelines for Australians, which recommend a minimum of 30 minutes of moderate intensity physical activity on most, preferably all, days (45).

5. Supplement recommendations

This section contains one question and five marks are given if no supplements are recommended. The dietary guidelines for Australians indicate that supplements should not be needed if a diet is nutritionally well balanced (46) and ideally even a weight loss diet should be able to provide a nutritionally adequate diet without the need for vitamin or mineral supplements. The ADA has stressed that supplements should not be used as replacements for nutrient-rich foods (32). A recent study that reviewed the evidence for the effectiveness of popular, non-prescription weight loss supplements in Australia concluded that there was no good evidence of any weight loss benefits from most of the 15 substances in the review (47).

6. Claims

Books are given five points if all claims made are supported clearly by scientific evidence or public health policy. Books making claims that are misleading, unsubstantiated by research, or purely anecdotal are given no points. This is in line with the position of DAA, warning the public to be wary if the author of a diet book made outlandish claims (29). The ADA has also warned consumers about claims that sound too good to be true (32). Examples of unacceptable claims for diets include using special combination of foods or supplements that would enable effortless weight loss.

7. Authors' credentials 

This section is worth a total of five marks. The ADA has stressed the importance of checking the author's qualifications and advises that a reputable author is usually one whose educational background and/or current affiliation is with an accredited university of medical centre with programs in nutrition, medicine, or a closely related discipline (48). The DAA has also recommended that consumers look for authors who have recognised nutrition qualifications (29), as have other experts (24). Authors with university qualifications in nutrition are given the maximum score of five. Any author with university qualifications in medicine or physiology is given a slightly lower score of three. Authors with qualifications in alternative medicine are not given any marks for this question.

8. Scientific evidence

This last section is allocated a total of ten marks. It includes a question on whether the recommendations in the book are based on published scientific evidence, rather than testimonials. A second question asks whether the author refers the reader to further credible sources of nutrition information. The ADA has warned that case histories, testimonials, and subjective evidence should be viewed with scepticism, and that evaluation of nutrition information can only be done through proper interpretation of scientific studies (48).

Part 2: Applying the assessment questionnaire to review popular diet books

Twenty diet books were chosen for review, based on the advice of staff at local bookstores about the most popular titles (49-68) (see Table 1). In order to test the performance of the questionnaire, a number of aspects were evaluated.

Practicality

The energy content and macronutrient composition of each diet was calculated by dietary analysis of three days of each menu plan, using the FoodWorks nutrient analysis software package (Xyris Software, Brisbane, FoodWorks Nutrient Analysis Software, Brisbane version 2.0 1998) with the AusNut food composition databases (Australia New Zealand Food Authority, Canberra: AUSNUT--Australian Food and Nutrient Database; 1999). If analytical data on foods were not available in AusNut, values were taken from the NUTTAB95 database (NUTTAB95 Data Tables for Use in Australia. Canberra: Australian Government Publishing Service; 1995). Books that provided multiple sample menus had the first three days menus analysed to calculate the macronutrient and energy content of the diets. Some books supplied menus but did not specify serving sizes. In this situation, the average serving sizes in the Foodworks program were used as the estimated amounts, although this may have underestimated the requirements for a more active person or for some males. Not all books contained sample menus, some merely provided a list of suggestions for each meal and for snacks. In this case, the first three items on each of the breakfast, lunch and dinner lists were included in the analysis. The first six items on the snack list were also included (one for mid morning and the other for mid afternoon each day, if permitted). When recipes from the books were analysed, salt was not included unless specifically stated in a recipe.

Validity

The calculated mean daily nutrient intakes based on the three-day menus were compared to the recommended dietary intakes (RDI) for a male (assumed to have a height of 175. cm and a weight of 81.2 kg) and a female (163.1 cm tall and weighing 64.3 kg)(69). These were the average heights and weights for males and females aged 25-44 years, reported in the 1995 National Nutrition Survey (70). Values for dietary fibre intake were compared with the recommended intake of 30 g per day (42).

The validity of the nutritional adequacy section of the questionnaire (questions 1-10) was tested by comparing the nutrition sub-score (out of 40) with the maximum number of nutrients found to be provided at less than 100% or 70% of the RDI, for either the reference man or woman.

Sensitivity

Ideally an assessment method should be able to discriminate between the quality of different diets across a wide numerical range, so that diets can be categorised easily into broad bands that relate to their acceptability. The final overall scores were examined to measure the range of the scores and whether they could categorised into bands for summary descriptions of the diets as recommended, adequate, or not recommended.

Statistical analysis

Statistical analyses were undertaken using SPSS for Windows 11.0 (SPSS Inc, Chicago, SPSS for Windows, version 11.0 2002). The relationships between the overall score (out of 100) or the nutrition sub-score (out of 40) and the numbers of nutrients likely to be provided at < 70% RDI or < 100% RDI were assessed by calculation of the Spearman's rank correlation coefficient. One-way analysis of variance with Bonferroni post-hoc comparison was used compare the mean scores of books written by those with nutrition qualifications, those with medical qualifications, and others. For this comparison, the total scores were adjusted to exclude the maximum score of five related to author's qualifications. A significance level of < 0.05 was applied to all statistical tests.

Results

Description of the diets and nutrient adequacy

Table 1 lists the books that were reviewed, author details and a summary of the approaches taken to weight loss management. The scores in each category of assessment and the total score of each book out of 100 are shown in Table 2. Table 3 sets out the nutrients potentially at risk in each diet, expressed as the percentage of adult daily recommended intake provided by each diet, based on the nutrient analysis of three days of menus.

A total of 35 diets from the 20 books were analysed. Only two (Licence to eat and The Volumetrics weight control plan) supplied at least 100% of the RDI for all nutrients. The nutrients that were provided below 100% of the RDI for women included zinc (low in 59% of the diets), iron (low in 41% of the diets), calcium (low in 38% of the diets) and magnesium (low in 29% of the diets). For men, the following nutrients were often below the RDI: zinc (low in 53% of the diets), magnesium (low in 44% of the diets), calcium (low in 38% of the diets), riboflavin (low in 35% of the diets) and thiamin (low in 26% of the diets).

Practicality

In general the questionnaire was able be implemented easily. However, the calculation of energy and macronutrient content was not always straightforward and required some decisions to standardise the procedures, as described in the Methods section. A few specific procedures were adopted for individual diets:

   The carbohydrate addict's diet:

   The daily menu plans only specified the foods to be
   included at breakfast and lunch. The other daily
   'reward meal' could include anything, however the
   authors recommend the use of low-fat dairy, lean
   meat/fish/poultry, vegetables/salad, whole grains, and
   fruits at the reward meal. Reward meals for analysis
   were chosen with these recommendations in mind, but
   obviously may not be typical of the foods chosen by
   other people.

   The liver cleansing diet and Eat right 4 your type:

   The fat and calcium content of soy milk was not specified
   in either book. Calcium-fortified, full-cream soy
   milk was used in the analyses.

   Stop the insanity!:

   No sample meal plan was included in the book. The
   author provides a few meal suggestions and examples
   of foods that she sometimes eats. The analysis was
   based on these foods. The author recommends approximately
   1750 calories (7350 kJ) for a 64.3 kg female
   and 1930 calories (8100 kJ) for an 81.2 kg male, so
   each of the three days' diets were constructed to be as
   close as possible in energy content to these
   recommendations.

   Fat free forever:

   The author recommends one 'junk food' meal per
   week to 'speed up the metabolism'. The reader is
   encouraged to eat 'anything from pizza to pasta with
   cream, or fried chicken and a chocolate sundae'. The
   analysis included two days of the Fat Free Forever
   diet, plus one with a 'junk food' meal (three slices of
   pizza and a milkshake), but this may not be typical of
   the choices made by other readers.

   Licence to eat:

  The book did not contain a specific menu plan. Foods
  were chosen from the author's lists of ideas for each
  meal. Adjustments were made to ensure that ten fibre-serves,
  three to four calcium serves, and three iron
  serves were chosen each day, in accordance with the
  author's recommendations.

The section of the questionnaire relating to evaluation of the claims made about the diet required professional judgement. This introduces some lack of precision into the tool and makes it unsuitable to be used by the general public in the current from. However, this question accounts for only five percent of the final total score. Examples of claims in the books that were classified as unacceptable were:

* 'a carbohydrate-restricted diet is so effective at dissolving adipose tissue that it can create fat loss greater than occurs in fasting';

* 'when eaten on an empty stomach, fresh fruit can have only a positive effect; it accelerates weight loss';

* 'the key to successful weight loss and maintenance is to restore efficient liver function'

* 'it is not only what you eat that makes the difference, but also of extreme importance is when you eat and in what combinations'.

Validity

Table 4 compares the nutrition scores from the first ten questions (maximum score 40) and the nutritional adequacy of the diets, as assessed by the number of nutrients that were provided in quantities less than

70% of less than 100% RDI. There was a strong correlation with both measures (Spearman's rho = -0.671 and -0.731 respectively; P < 0.01), suggesting that the ten questions provide a good indication of the nutritional adequacy of the diets. There was also a strong correlation between the number of nutrients that were provided in quantities less than 70% or less than 100% RDI and the overall rating score out of 100 (Spearman's rho = -0.618 and -0.653; P < 0.01). Such a correlation is to be expected given the fact that the nutrition sub-score makes up 40% of the overall rating score.

Sensitivity

Among the 20 books evaluated there was a wide range of scores, from 32 to 97. This indicates that the evaluation tool is capable of discriminating between the books in a useful way. Using the detailed nutritional assessments as a guide to the overall adequacy, the following bands of ranking the total scores can be suggested:

   81 100: Recommended
   61-80: Adequate (but some areas need
          improvement)
   1-60: Not recommended

This division is somewhat arbitrary, but the five diets which achieved an overall rating of greater than 80 had a mean nutrition score of 34 out of 40 and provided 100% of all nutrients--or at most two between 70 and 90% RDI (either zinc or calcium). The sole exception was The diet that works! which provided just 69% of the riboflavin RDI for males. Those books with a total score of 60 or less had a mean nutrition score of only 15 out of 40 and an average of three nutrients provided at less than 70% RDI.

There was a significant difference in the scores of books according to the authors' qualifications. Considering the total score without the five points related to author qualifications (i.e. out of a maximum of 95 only), books by those with recognised tertiary nutrition qualifications (n = 5) had a mean score of 83, those by medical practitioners (n = 6) had a mean score of 52, and those by other authors (n = 9) scored 48. The differences between the scores of the books by nutrition authors and both other groups were significant (P < 0.02), but the difference between medical and other authors was not.

Discussion

Given that there is no gold standard by which to assess popular diet books, the scoring system used in this tool is rather arbitrary. The weighting of values given to the different sections of the rating score was based on the judgement of the authors. In particular it was decided that the nutritional scores and scientific evidence (which together make up half of the overall rating) should predominate, in order that those using recommended diets can be confident that they are safe and nutritionally adequate.

For the sake of simplicity, most of the nutrition sub-scores were scored either as zero or full marks. For example, if the diet included at least five serves of vegetables per day it achieved a score of four, if less than five were included the score was zero. It would be possible to construct a more refined scoring system depending on how close the diet was to the target, in the way that the US Healthy Eating Index was constructed (71), but it was decided not to adopt this approach in order to reduce the complexity of the scoring.

The validity of the nutrition component of the questionnaire was evaluated by examining how well the scores correlated with nutritional adequacy determined by analysis of three days of the diet plans, a method that has been used to validate other assessment tools (71,72). While the two scores do not measure precisely the same aspects of the diet, they both relate to overall nutritional quality. The results in Table 4 provide reassurance that the semi-qualitative assessment of the diet, using the questions about food groups and macronutrient targets in the questionnaire, is meaningful when evaluated in terms of the quantitative assessment of provision of nutrients.

It must be acknowledged it can be difficult to ensure 100% RDI is met for all micronutrients when planning energy restricted diets. Indeed with some low energy diets it may be appropriate to recommend a general vitamin and mineral supplement to ensure all requirements are met. However it is notable that with one minor exception none of the books that scored above 80 provided less than 70% RDI for any nutrient and only a few were marginally below the RDI for nutrients like zinc and calcium. The recommendations for these nutrients are among the most difficult to meet using basic unfortified foods (73), and slight deficits are unlikely to be nutritionally significant, especially when energy reduction diets are not usually intended for lifelong use.

It is not possible to make direct comparisons of the scores using this method with other evaluations made of popular weight loss diets, however the results are generally consistent with other assessments. Berland in his 1983 review rated the Atkins diet revolution as not recommended and the Scarsdale diet was given a rating of two stars (out of four), which compare with the ratings of 35 and 44 (out of 100) respectively given with our method (16). In a more recent Australian nutrition book, the following diets are criticised for incorrect or unbalanced advice, which is consistent with the fact that none scored above 60 in the assessment reported here (scores shown after each): Sugar Busters (40), Fit for Life (41), Eat Right 4 Your Type (36), Dr Atkins' New Diet Revolution (35) (74).

Nutrition and exercise advice

In one instance, the percentage of energy from carbohydrate, protein and fat (analysed by computer program) was different from the figures quoted by the author. Barry Sears, author of The zone--A dietary road map, claimed that the key to permanent weight loss and optimal health is consumption of a diet containing 40%E carbohydrate, 30%E protein, and 30%E fat. Analysis of three days of menus from the diet indicated they provided 35%E carbohydrate, 39%E protein, and 25%E fat. This discrepancy has been noted by other authors (75).

Thirteen diets in eight books contained a higher percentage of energy from protein than the target of 12 to 25%. Seven diets contained 30% energy or more from protein and less than 40% from carbohydrate. Low carbohydrate diets often result in initial rapid weight loss, however this is mainly due to excessive water loss rather than loss of body fat. Possible complications of low-carbohydrate, high-protein diets include ketosis, dehydration, loss of electrolytes, calcium depletion, weakness, nausea and possibly kidney problems. People following these diets are also at risk of inadequate vitamin and mineral intake (25) and a review of the outcomes of popular diets reported that lower scores on a healthy eating index were associated with low-carbohydrate diets (76). Controlled studies have not shown any significant differences in weight loss when low and high carbohydrate hypocaloric diets were compared (77) and the results of several studies have refuted the contention that low carbohydrate diets, in the absence of energy restriction, provide a metabolic advantage for weight loss (76). For all these reasons the NHMRC has concluded that there is no long-term evidence supporting the use of 'popular' low carbohydrate or high protein diets (34).

It is still not proven that dramatic manipulation of the macronutrient balance of the diet will have substantial effects on weight loss. Energy restriction remains the key variable associated with weight loss in the short term (76) and those most likely to be successful at long-term weight control are those following a low-fat low energy diet (78). Researchers recently analysed the diets of more than 2600 members of the US National Weight Control Registry, who had maintained a weight loss of at least 30 pounds (approximately 13.6 kg) for one year or longer. Although high protein diets have been used for more than 30 years, the researchers found that less than 1% of successful dieters had followed a high protein diet and concluded that such diets may not create any metabolic advantage (79).

One book (Fit for life) promoted a diet that was found to be low in protein (< 10%E). It was a food-combining diet, which involved eating mainly fruit and vegetables. Low-energy food-combining diets have not been found to provide any metabolic benefits over low-energy balanced diets in terms of weight loss, blood pressure, fasting plasma glucose, cholesterol or triglyceride levels (80). It has been argued that food-combining may create deficiencies in zinc, vitamin B12, protein and calcium due to the elimination of major food groups (81).

Almost one third of the diets were high in fat (> 30%E), while 11 diets (in seven books) contained more than 300 mg of cholesterol per day. Fourteen diets (ten books) contained more than 2300 mg of sodium. Some diets took the low-fat recommendation to excess, with two of the diets (Eat More Weigh Less; Stop the Insanity!) providing less than 10%E from fat. Although diets high in dietary fibre have been shown to help reduce food intake (82), the majority of these diets provided less than 30 g of dietary fibre per day, with the low carbohydrate diets supplying the least amount.

Six books relied on special supplements or products. A review of potential supplements to assist weight reduction, conducted in developing the NHMRC draft clinical guidelines for weight control, concluded there is no convincing evidence that any popular supplements are necessary or assist weight loss (34).

All diet books mentioned the need for physical activity. Fourteen of the books contained exercise suggestions that were consistent with the recommendations from the National Physical Activity Guidelines for Australians (45). Few authors recommended a medical check up prior to commencing an exercise program.

In general the level of energy prescribed was reasonable. Three diets, The Complete Scarsdale Medical Diet, Sugar Busters and The Zone Diet, contained less than 4200 kJ per day, and five promised undesirably rapid rates of weight loss--The Complete Scarsdale Medical Diet, Dr Atkins' New Diet Revolution, Fit for Life, The Liver Cleansing Diet, and Slim Forever.

Flexibility and sustainability

Every diet made some allowance for individual preference and taste by offering a variety of options, even though some diets contained only a limited range of foods. Ten diets achieved the maximum score of 15 for overall flexibility and sustainability (see Table 2).

Authors' credentials and scientific evidence

The two books with the highest overall scores (> 95) were written by a professor of nutrition and a dietitian, but only five authors overall had university qualifications in nutrition. It might be argued that authors' credentials should not be included in the total assessment score since the value of nutrition expertise should be assessable by the dietary advice provided. In practice this sub-score had no effect on the final ranking of the books, but because it is a factor recommended for consideration by many experts (8,24,29,48) it has been left in the final assessment tool.

Only three books received the maximum marks for the two questions relating to evidence: Licence to eat, The Volumetrics weight-control plan, and The omega plan. Most relied on unreferenced of unsubstantiated claims.

Conclusions

The questionnaire developed here has been found to be practical and potentially useful in providing a quantitative assessment of the adequacy and sustainability of the advice provided in popular diet books. Further research is required to assess its reproducibility when used by different assessors. Applying the questionnaire to a sample of currently popular diet books it was found that 11 out of 20 books could not be recommended (with scores of 60 or less out of 100). The findings from this study are similar to those from previous studies and reviews which have found many fad diets to be lacking in both nutritional adequacy, and without scientific evidence (15,16,22,24).

The questionnaire described here may be useful for dietitians and other health professionals who want to evaluate diet books or make recommendations about the development of new diets. Accurate advice to the public is an essential part of any strategy to address the national obesity problem (83) and it is the responsibility of nutrition scientists to speak out about questionable nutrition advice, particularly that which has not been proven to be safe (84). As the questionnaire requires the skills of a trained professional to carry out the nutrient analysis and make some judgements about the claims made, in its current form it is not a tool that can be used by members of the public to assess books themselves. In the future, it would be useful to refine this method to develop a simpler version that could be used by consumers directly.

Appendix 1. Diet rating questionnaire

                                                        SCORE

Nutritional adequacy (maximum score = 40)

1. Does the diet include at least 4 serves of
   bread/cereals per day for women, or 6 serves
   for men?                                          (Yes = 4)____
   1 serve =
   2 slices (60 g) bread, 1 medium bread roll
   1 cup (180 g) cooked rice, pasta, noodles
   1 cup (230 g) cooked porridge
   1 1/3 cups (40 g) cereal flakes or ready to eat
   cereal
   1/2 cup (65 g) untoasted muesli
   1/3 cup (40 g) flour

2. Does the diet include at least 5 serves of
   vegetables, legumes per day?                      (Yes = 4)____
   1 serve =
   1/2 cup (75 g) cooked vegetables, cooked dried
   beans, peas or lentils
   1 cup salad vegetables
   1 small potato

3. Does the diet include at least 2 serves per day
   of fruit?                                         (Yes = 4)____
   1 serve =
   1 medium piece (150 g) of fruit (apple, banana,
   orange, pear)
   2 small pieces (150 g) of fruit (apricots,
   kiwifruit, plums)
   1 cup (150 g) diced pieces or canned fruit
   1 1/2  tablespoons sultanas, 4 dried apricot
   halves
   1/2 cup (125 ml) fruit juice

4. Does the diet include at least 2 serves per day
   of milk, yoghurt or cheese?                       (Yes = 4)____
   1 serve =
   1 cup (250 mL) fresh, longlife or reconstituted
   dried milk
   1 cup (250 mL) soy milk (fortified with at
   least 100 mg calcium/100 ml)
   1/2 cup (125 mL) evaporated milk
   2 slices (40 g) cheese
   1 small carton (200 g) yoghurt
   1 cup (250 mL) custard

5. Does the diet include at least 1 serve per day
   of meat, fish, poultry, eggs, nuts, legumes?      (Yes = 4)____
   1 serve =
   65-100 g cooked meat, chicken (e.g. 1/2 cup
   lean mince, 2 small chops,
   2 slices roast meat)
   1/3 cup peanuts, almonds or 1/4 cup sunflower
   seeds, sesame seeds

6. Does the diet provide 30% or less energy from
   fat (with < 10% saturated and trans
   fatty acids)?                                     (Yes = 4)____

7. Does the diet provide adequate carbohydrate
   intake?
   (a) 55-60% energy from carbohydrate               (Yes = 4)____
   (b) 50-54% energy from carbohydrate               (Yes = 3)____

8. Does the diet provide 12-25% energy from
   protein?                                          (Yes = 4)____

9. Does the diet limit alcohol intake?               (Yes = 4)____
   (Max 2 standard drinks per day; 1-2
   alcohol-free days per week)

10.Does the diet provide adequate dietary fibre
   intake?
   (a) 30 g or more dietary fibre per day            (Yes = 4)____
   (b) 25-29 g of dietary fibre per day              (Yes = 3)____

Energy allowed and recommended rate of weight loss (maximum score = 10)

11.Does the diet contain a minimum of 4200
   kilojoules
   per day?                                          (Yes = 5)____

12.Is the promised rate of weight loss no more
   than 1 kilogram per week?                         (Yes = 5)____

Flexibility and sustainability (maximum score = 15)

13.Does the diet allow for individual preference
   and taste?                                        (Yes = 5)____

14.Does the diet encourage permanent, realistic
   lifestyle changes, enabling
   it to be followed long term?                      (Yes = 5)____
   (e.g. does it suggest ways to incorporate
   exercise into a busy lifestyle, or provide
   advice on the most appropriate choices to
   make when dining out?)

15.Does the diet provide advice on supportive
   behavioural changes rather than
   merely advising which foods to choose or
   limit?                                            (Yes = 5)____
   (e.g. does it suggest alternative methods
   for dealing with stress or depression,
   or provide suggestions on how to break
   unwanted habits such as eating
   while reading or watching television?)

Physical activity (maximum score = 10)

16.Does the author discuss the importance of
   physical activity for effective
   weight control?                                   (Yes = 5)____

17.Are people advised to carry out at least 30
   minutes of moderate-intensity
   physical activity on most, preferably all,
   days?                                             (Yes = 5)____

Supplement recommendations (maximum score = 5)

18.Does the diet avoid reliance on special
   supplements or products?                          (Yes = 5)____

Claims (maximum score = 5)

19.Does the author avoid making exaggerated
   claims, promoting the diet in an extravagant
   way?                                              (Yes = 5)____
   (e.g. faster weight loss than any other method;
   no need to restrict amount of food eaten)

Authors' credentials (maximum score = 5)

20.Do the authors have appropriate educational
   qualifications?
   (a)University qualifications in nutrition or
   dietetics?                                        (Yes = 5)____
   (b) University qualifications in medicine or
   physiology?                                       (Yes = 3)____

Scientific evidence (maximum score = 10)

21.Are the recommendations based on published
   scientific evidence, rather than testimonials?    (Yes = 5)____

22.Does the author refer the reader to other
   credible sources of nutrition information?        (Yes = 5)____
   (e.g. the Dietitians Association of Australia
   or the National Heart Foundation)

                        Total rating for the diet  (max = 100)____

Table 1. Summary of the diets evaluated

Diet                                       Author's credentials
The Carbohydrate Addict's Diet (49)        Psychologist

The Complete Scarsdale Medical Diet (50)   Cardiologist
      14-day medical diet

Diet Signs - The Health Signs Diet (51)    Astrologer
      Air signs diet
      Earth signs diet
      Fire signs diet
      Water signs diet

The Diet that Works! (52)                  Medical practitioner

Dr Atkins' New Diet Revolution (53)        Medical practitioner
      Induction diet
      Ongoing weight loss diet
      Maintenance diet

Eat More Weigh Less (54)                   Professor of medicine

Eat Right 4 Your Type (55)                 Naturopath
      Type A diet
      Type AB diet
      Type B diet
      Type O diet

Fat Free Forever (56)                      Fitness leader
                                           Personal trainer

Fat Loss For Life (57)                     BSc
                                           Grad Dip Nutr.
                                           Dip Naturopathy and
                                           Homeopathy.
The Fat Stripping Diet (58)                MSc (Nutrition)
      Female plan
      Male plan

Fit For Life (59)                          Nutrition qualification
                                           from non-accredited
                                           institution

Licence to Eat (60)                        Dietitian

The Liver Cleansing Diet (61)              Medical practitioner

The Omega Plan (62)                        Medical practitioner
      4800 kJ plan                         Chaired the Nutrition
      6300 kJ plan                         committee of the National
                                           Institute of Health

Rosemary Conley's Red Wine Diet (63)       Publisher: diet and fitness
      1400 calorie plan                    magazine
      2000 calorie plan

Slim Forever (64)                          Chiropractor
      60 kg ideal weight
      70 kg ideal weight

Stop the Insanity! (65)                    Motivational speaker, owns
      1750 calorie diet                    an exercise studio
      1930 calorie diet

Sugar Busters! (66)                        Endocrinologist

The Volumetrics Weight Control Plan (67)   PhD
      1600 calorie plan                    Holds the Guthrie Chair of
      2000 calorie plan                    Nutrition at Penn State Uni

The Zone-A Dietary Road Map (68)           PhD (biochemistry)
      8 protein blocks
      12 protein blocks

Diet                                       Supplements
The Carbohydrate Addict's Diet (49)        Not mentioned

The Complete Scarsdale Medical Diet (50)   Not mentioned
      14-day medical diet

Diet Signs - The Health Signs Diet (51)    Vitamin, mineral and herbal
      Air signs diet                       supplements recommended
      Earth signs diet
      Fire signs diet
      Water signs diet

The Diet that Works! (52)                  Avoids reliance on
                                           supplements

Dr Atkins' New Diet Revolution (53)        Sells and recommends
      Induction diet                       many vitamins, minerals,
      Ongoing weight loss diet             low CHO bars, shakes and
      Maintenance diet                     bread mixes

Eat More Weigh Less (54)                   Avoids reliance on
                                           supplements

Eat Right 4 Your Type (55)                 Variety of supplements
      Type A diet                          recommended
      Type AB diet
      Type B diet
      Type O diet

Fat Free Forever (56)                      Variety of vitamin and
                                           mineral supplements
                                           recommended

Fat Loss For Life (57)                     Avoids reliance on
                                           supplements

The Fat Stripping Diet (58)                Avoids reliance on
      Female plan                          supplements
      Male plan

Fit For Life (59)                          Claim that supplements are
                                           not needed & that fruits &
                                           veg contain all necessary
                                           nutrients

Licence to Eat (60)                        Avoids reliance on
                                           supplements

The Liver Cleansing Diet (61)              Sells and recommends many
                                           supplements

The Omega Plan (62)                        Avoids reliance on
      4800 kJ plan                         supplements
      6300 kJ plan

Rosemary Conley's Red Wine Diet (63)       Daily multivitamin while
      1400 calorie plan                    dieting
      2000 calorie plan

Slim Forever (64)                          Avoids reliance on
      60 kg ideal weight                   supplements
      70 kg ideal weight

Stop the Insanity! (65)                    Not mentioned
      1750 calorie diet
      1930 calorie diet

Sugar Busters! (66)                        Avoids reliance on
                                           supplements

The Volumetrics Weight Control Plan (67)   Avoids reliance on
      1600 calorie plan                    supplements
      2000 calorie plan

The Zone - A Dietary Road Map (68)         Recommends various
      8 protein blocks                     vitamins. Sells and
      12 protein blocks                    recommends zone-favourable
                                           bars and powders.

                                           Physical activity
Diet                                       recommendations

The Carbohydrate Addict's Diet (49)        Increase incidental exercise

The Complete Scarsdale Medical Diet (50)   Walking, swimming, golf,
      14-day medical diet                  tennis

Diet Signs - The Health Signs Diet (51)    20 mins/day, three times
      Air signs diet                       weekly
      Earth signs diet
      Fire signs diet
      Water signs diet

The Diet that Works! (52)                  Increase incidental
                                           activity, and
                                           add 30-60 mins/day of
                                           walking

Dr Atkins' New Diet Revolution (53)        Minimum 30 mins walking per
      Induction diet                       day
      Ongoing weight loss diet
      Maintenance diet

Eat More Weigh Less (54)                   Walk 20-60 mins per day. Add
                                           moderate resistance training
                                           (e.g. light weights)

Eat Right 4 Your Type (55)                 Recommendations vary
      Type A diet                          according to blood type.
      Type AB diet                         Approx
      Type B diet                          30 mins aerobic exercise
      Type O diet                          recommended on most days for
                                           blood types O and B

Fat Free Forever (56)                      Walking and resistance
                                           training
                                           recommended

Fat Loss For Life (57)                     30 mins aerobic exercise per
                                           day. Increase incidental
                                           activity

The Fat Stripping Diet (58)                Certain rules must be
      Female plan                          followed
      Male plan                            to maximise fat burning (e.g.
                                           exercise 2-3 hrs after meals;
                                           weight training must be done
                                           after walking/low intensity
                                           exercise)

Fit For Life (59)                          20 mins aerobic exercise per
                                           day

Licence to Eat (60)                        Importance of aerobic &
                                           incidental exercise

The Liver Cleansing Diet (61)              Acknowledges the importance
                                           of exercise but does not
                                           elaborate on this

The Omega Plan (62)                        Minimum 45 mins exercise per
      4800 kJ plan                         day
      6300 kJ plan

Rosemary Conley's Red Wine Diet (63)       30 mins aerobic exercise 3-5
      1400 calorie plan                    times per week
      2000 calorie plan

Slim Forever (64)                          Acknowledges the importance
      60 kg ideal weight                   of daily exercise but does
      70 kg ideal weight                   not
                                           specify the amount required

Stop the Insanity! (65)                    30-60 mins of aerobic
      1750 calorie diet                    exercise
      1930 calorie diet                    per day

Sugar Busters! (66)                        20 mins exercise at least 4
                                           times per week

The Volumetrics Weight Control Plan (67)   Advice re: stretching,
      1600 calorie plan                    warming
      2000 calorie plan                    up, inclusion of some longer
                                           exercise sessions, varying
                                           the
                                           intensity, trying weights

The Zone - A Dietary Road Map (68)         Importance of aerobic
      8 protein blocks                     exercise
      12 protein blocks                    such as walking for 6 hrs or
                                           jogging for 3 hrs per week

                                           Average daily energy
                                           intake (Cal/kJ), based on
Diet                                       analysis of 3 days' menus

The Carbohydrate Addict's Diet (49)        1724 Cal (7217 kJ)

The Complete Scarsdale Medical Diet (50)   506 Cal (2120 kJ)
      14-day medical diet

Diet Signs - The Health Signs Diet (51)
      Air signs diet                       1332 Cal (5577 kJ)
      Earth signs diet                     1254 Cal (5248 kJ)
      Fire signs diet                      1432 Cal (5994 kJ)
      Water signs diet                     1204 Cal (5042 kJ)

The Diet that Works! (52)                  1672 Cal (7000kJ)

Dr Atkins' New Diet Revolution (53)
      Induction diet                       1467 Cal (6141 kJ)
      Ongoing weight loss diet             2511 Cal (10 512 kJ)
      Maintenance diet                     3175 Cal (31 293 kJ)

Eat More Weigh Less (54)                   1469 Cal (6150 kJ)

Eat Right 4 Your Type (55)
      Type A diet                          1074 Cal (4496 kJ)
      Type AB diet                         1036 Cal (4335 kJ)
      Type B diet                          1300 Cal (5441 kJ)
      Type O diet                          1229 Cal (5144 kJ)

Fat Free Forever (56)                      1874 Cal (7846 kJ)

Fat Loss For Life (57)                     1546 Cal (6472 kJ)

The Fat Stripping Diet (58)
      Female plan                          1362 Cal (5703 kJ)
      Male plan                            1492 Cal (6244 kJ)

Fit For Life (59)                          1883 Cal (7880 kJ)

Licence to Eat (60)                        1916 Cal (8020kJ)

The Liver Cleansing Diet (61)              1481 Cal (6198 kJ)

The Omega Plan (62)
      4800 kJ plan                         1110 Cal (4647 kJ)
      6300 kJ plan                         1558 Cal (6523 kJ)

Rosemary Conley's Red Wine Diet (63
      1400 calorie plan                    1316 Cal (5507 kJ)
      2000 calorie plan                    1968 Cal (8236 kJ)

Slim Forever (64)
      60 kg ideal weight                   1535 Cal (6424 kJ)
      70 kg ideal weight                   1714 Cal (7177 kJ)

Stop the Insanity! (65)
      1750 calorie diet                    1757 Cal (7356 kJ)
      1930 calorie diet                    1930 Cal (8079 kJ)

Sugar Busters! (66)                        966 Cal (4043 kJ)

The Volumetrics Weight Control Plan (67)
      1600 calorie plan                    1778 Cal (7441 kJ)
      2000 calorie plan                    2131 Cal (8920 kJ)

The Zone - A Dietary Road Map (68)
      8 protein blocks                     817 Cal (3418 kJ)
      12 protein blocks                    1226 Cal (5131 kJ)

Diet                                       Theory behind the diet

The Carbohydrate Addict's Diet (49)        Low CHO (a)

The Complete Scarsdale Medical Diet (50)   Low CHO, low fat
      14-day medical diet

Diet Signs - The Health Signs Diet (51)    Health requirements are
      Air signs diet                       determined by the stars
      Earth signs diet
      Fire signs diet
      Water signs diet

The Diet that Works! (52)                  High CHO, moderate protein,
                                           low fat

Dr Atkins' New Diet Revolution (53)        Low CHO, high protein, high
      Induction diet                       fat
      Ongoing weight loss diet
      Maintenance diet

Eat More Weigh Less (54)                   Very low fat (< 10%), high
                                           CHO

Eat Right 4 Your Type (55)                 Blood type determines diet.
      Type A diet                          A: high CHO, low fat,
      Type AB diet                         vegetarian diet. B: varied
      Type B diet                          diet.
      Type O diet                          AB: combination of A and B
                                           diets. O: high protein, low
                                           CHO

Fat Free Forever (56)                      Author advocates low fat,
                                           increased protein and
                                           avoidance of starchy CHO
                                           after 3.00 pm

Fat Loss For Life (57)                     High CHO, moderate protein,
                                           low fat

The Fat Stripping Diet (58)                High CHO, moderate protein,
      Female plan                          low fat
      Male plan

Fit For Life (59)                          Food combining

Licence to Eat (60)                        High CHO, moderate protein,
                                           low fat

The Liver Cleansing Diet (61)              Excess weight is a symptom of
                                           liver dysfunction.
                                           Liver-cleansing foods enable
                                           the liver
                                           to efficiently metabolise fat

The Omega Plan (62)                        Advocates a diet that is low
      4800 kJ plan                         in
      6300 kJ plan                         saturated and trans fatty
                                           acids,
                                           but which contains generous
                                           amounts of omega 3 and
                                           monounsaturated fats

Rosemary Conley's Red Wine Diet (63)       High CHO, moderate protein,
      1400 calorie plan                    low fat. Includes up to
      2000 calorie plan                    three
                                           glasses red wine/day

Slim Forever (64)                          Low CHO, high protein, high
      60 kg ideal weight                   fat
      70 kg ideal weight

Stop the Insanity! (65)                    Very low fat, low-moderate
      1750 calorie diet                    protein, high CHO
      1930 calorie diet

Sugar Busters! (66)                        Low sugar, low GI. Restricts
                                           many healthy foods (e.g.
                                           carrots, potatoes, corn,
                                           beets,
                                           white rice)

The Volumetrics Weight Control Plan (67)   High CHO (high fibre, high
      1600 calorie plan                    water content), moderate
      2000 calorie plan                    protein, low fat

The Zone - A Dietary Road Map (68)         Advocates 40% CHO, 30%
      8 protein blocks                     protein, 30% fat to ensure
      12 protein blocks                    the
                                           correct balance of insulin
                                           and
                                           glucagon. Claims that this
                                           enables more 'good'
                                           eicosanoids to be produced
                                           which aid weight control and
                                           immune function

(a) CHO = carbohydrate

Table 2. Rating of the 20 diet books (ranked from highest to lowest by
total score)

                           Nutritional      Energy
                           Adequacy (a)    allowance
Diet                         (max 40)       (max 10)

The volumetrics weight         35-39           10
control plan
Licence to eat                   36            10
Fat loss for life                32            10
The diet that works!             32            10
Eat more weigh less              32            10
The fat stripping diet         23-27           10
The omega plan                 12-23           10
Stop the insanity!             32-36           10
Rosemary Conley's red           8-15           10
wine diet
Fat free forever                 19            10
Diet signs--The health          8-19           10
signs diet
The complete Scarsdale           16             0
medical diet
The carbohydrate addicts          8            10
diet
The liver cleansing diet         24             5
The zone--A dietary road       12-16            5
map
Fit for life                     16             5
Sugar busters!                   12             5
Eat right 4 your type          12-16           10
Dr Atkins' new diet             8-16            5
revolution
Slim forever                     12             5

                           Flexibility
                               and          Physical
                           sustainability   activity
Diet                          (max 15)      (max 10)

The volumetrics weight           15               10
control plan
Licence to eat                   15               10
Fat loss for life                15               10
The diet that works!             15               10
Eat more weigh less              15               10
The fat stripping diet           15               10
The omega plan                   15               10
Stop the insanity!               10               10
Rosemary Conley's red            15               l0
wine diet
Fat free forever                 15               10
Diet signs--The health           10                5
signs diet
The complete Scarsdale           10               10
medical diet
The carbohydrate addicts         15                5
diet
The liver cleansing diet          5                5
The zone--A dietary road         10               10

Fit for life                     10                5
Sugar busters!                   10                5
Eat right 4 your type             5             5-10
Dr Atkins' new diet               5               10
revolution
Slim forever                      5                5

                           Supplements   Claims
Diet                         (max 5)     (max 5)

The volumetrics weight            5            5
control plan
Licence to eat                    5            5
Fat loss for life                 5            5
The diet that works!              5            5
Eat more weigh less               5            5
The fat stripping diet            5            5
The omega plan                    5            5
Stop the insanity!                5            0
Rosemary Conley's red             5            5
wine diet
Fat free forever                  0            5
Diet signs--The health            0            5
signs diet
The complete Scarsdale            5            0
medical diet
The carbohydrate addicts          5            0
diet
The liver cleansing diet          0            0
The zone--A dietary road          0            0
map
Fit for life                      5            0
Sugar busters!                    5            0
Eat right 4 your type             0            0
Dr Atkins' new diet               0            0
revolution
Slim forever                      5            0

                             Authors'    Scientific    Total
                           Credentials    evidence    score (b)
Diet                         (max 5)    (max 10)    (max 100)

The volumetrics weight            5             10           97
control plan
Licence to eat                    5             10           96
Fat loss for life                 5              5           87
The diet that works!              3              5           85
Eat more weigh less               3              5           85
The fat stripping diet            5              5           80
The omega plan                    5             10           78
Stop the insanity!                0              5           74
Rosemary Conley's red             0              5           62
wine diet
Fat free forever                  0              0           59
Diet signs--The health            0              0           45
signs diet
The complete Scarsdale            0              0           44
medical diet
The carbohydrate addicts          0              0           43
diet
The liver cleansing diet          3              0           42
The zone--A dietary road          3              0           42
map
Fit for life                      0              0           41
Sugar busters!                    3              0           40
Eat right 4 your type             0              0           36
Dr Atkins' new diet               3              0           36
revolution
Slim forever                      0              0           32

a) Range shown where several diet plans are given in the one book.
b) Total score calculated using the mean nutritional adequacy score.

Table 3. Nutrients potentially at risk in 20 popular diets: percentage
of adult daily recommended intake provided by each diet calculated from
analysis of 3    days of menus (a)

Diet                                  Fibre   VitA   VitB1   VitB2

The Carbohydrate Addict's Diet         48      79     84
The Complete Scarsdale Medical Diet    33             37       30
Diet Signs-The Health Signs Diet
   Air signs diet                              73     96
   Earth signs diet                    87
   Fire signs diet                     79             65
   Water signs diet                    63             58       93
The Diet that Works!                                           69
Dr Atkin
   Induction diet                      13             47       77
   Ongoing weight loss diet            41
   Maintenance diet                    80                      98
Eat More Weigh Less                                  75
Eat Right 4 Your Type
   Type A diet                         56            81-61     81
   Type AB diet                        65            70        76
   Type B diet                         52            71
   Type 0 diet                         68            79        62
Fat Free Forever                       80
Fat Loss For Life                                    97        95
The Fat Stripping Diet
   Female plan                         80
   Male plan                           89
Fit For Life                                         73
Licence to Eat
The Liver Cleansing Diet                             73
The Omega Plan
   4800kJ plan                        54             78        53
   6300kJ plan                        89                       62
Rosemary Conley's Red Wine Diet
   1400 calorie plan (female)         60             59
   2000 calorie plan (male)           87
Slim Forever
   60 kg ideal weight (female)        26
   70 kg ideal weight (male)          31                     82
Stop the Insanity!
   1750 calorie diet (female)                        85
   1930 calorie diet (male)                          65
Sugar Busters!                        58             65       73
The Volumetrics Weight Control Plan
The Zone-A Dietary Road Map
   8 protein blocks (female)          47             45
   12 protein blocks (male)           66             56

Diet                                  Vit C   Folate   Ca   Mg

The Carbohydrate Addict's Diet                   68    74
The Complete Scarsdale Medical Diet              82    23   39
Diet Signs-The Health Signs Diet
   Air signs diet
   Earth signs diet
   Fire signs diet                                          83
   Water signs diet                                         92
The Diet that Works!                                   82
Dr Atkins' New Diet Revolution
   Induction diet                                99    89   54
   Ongoing weight loss diet                                 75
   Maintenance diet
Eat More Weigh Less                                    87
Eat Right 4 Your Type
      Type A diet                                           90
      Type AB diet                                          91
      Type B diet                                           84
      Type 0 diet                                      50   93
Fat Free Forever
Fat Loss For Life
The Fat Stripping Diet
      Female plan
      Male plan                                             99
Fit For Life                                           64
Licence to Eat
The Liver Cleansing Diet                               84
The Omega Plan
      4800kJ plan                                      68   58
      6300kJ plan                                      80   82
Rosemary Conley's Red Wine Diet
      1400 calorie plan (female)
      2000 calorie plan (male)
Slim Forever
      60 kg ideal weight (female)               83     36   60
      70 kg ideal weight (male)                 92     44   58
Stop the Insanity!
      1750 calorie diet (female)                       41
      1930 calorie diet (male)                         44
Sugar Busters!                                         66   77
The Volumetrics Weight Control Plan
The Zone-A Dietary Road Map
      8 protein blocks (female)                             82
      12 protein blocks (male)

Diet                                  Zn   Fe   K   P
The Carbohydrate Addict's Diet        66   85
The Complete Scarsdale Medical Diet   54   48   95   60
Diet Signs-The Health Signs Diet
      Air signs diet                  87   94
      Earth signs diet                95
      Fire signs diet
      Water signs diet
The Diet that Works!                       88
Dr Atkins' New Diet Revolution
      Induction diet                  96   72   98
      Ongoing weight loss diet             86
      Maintenance diet
Eat More Weigh Less                   71
Eat Right 4 Your Type
      Type A diet                           58
      Type AB diet                    55
      Type B diet                           64   80
      Type 0 diet                           88
Fat Free Forever
Fat Loss For Life                     84
The Fat Stripping Diet
      Female plan                           80   92
      Male plan                       83
Fit For Life                          72
Licence to Eat
The Liver Cleansing Diet
The Omega Plan
      4800kJ plan                           66
      6300kJ plan                           87   96
Rosemary Conley's Red Wine Diet
      1400 calorie plan (female)      89   92
      2000 calorie plan (male)
Slim Forever
      60 kg ideal weight (female)     67   59
      70 kg ideal weight (male)       81
Stop the Insanity!
      1750 calorie diet (female)      99
      1930 calorie diet (male)
Sugar Busters!                        65   72
The Volumetrics Weight Control Plan
The Zone-A Dietary Road Map
      8 protein blocks (female)       65   62
      12 protein blocks (male)        97

(a) Male adult Australian RDI used as reference unless specified,
except for iron where female RDI used as standard
(69).30 g per day used as reference value for dietary fibre (42). No
entry in table     and other nutrients not included in
table indicates nutrient provided at greater than 100% RDI.

Table 4. Relationship between nutrition score and nutrients at risk in 20 popular diet books, as assessed by three-day diet analysis

                       Mean number of     Mean number of
Nutritional adequacy   nutrients less   nutrients less than
 score (out of 40)      than 70% RDI        100% RDI

31-40 (n=6)                      0                  1
21-30 (n =2)                 0                  2
11-20 (n =11)                2                  4
1-10 (n-1)                   3                  6

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Australian Research Council Key Centre for Smart Foods, University of Wollongong, New South Wales L. Williams, BA (Consumer Affairs) DipHumNutr, MSc(NutrDiet), Masters candidate P. Williams, BSc(Hons), DipNutrDiet, MHP, PhD, APD, Senior Lecturer Correspondence: P. Williams, Smart Foods Centre, Department of Biomedical Science, University of Wollongong NSW 2522. Email: [e-mail]