How to avoid middle-aged weight gain-sleep on it.

This one is going to surprise you. Some of us, even those who remain active and eat right, find that we gain unwanted weight as we age. What may be missing is enough sleep. In a study recently published in the Journal of the American Medical Association, lack of deep sleep was associated with decreases in a growth hormone. Deficiencies in that growth hormone have long been associated with decreases in lean body mass and increases in fat tissue.

As we age, our sleep patterns change significantly and most of us find we sleep less and less. In a study from the University of Chicago, 149 healthy men aged 16 to 83 were studied for sleep patterns along with growth hormone. The researchers found that the percentage of slow wave or deep sleep decreased by a factor of more than five and a half times from young adulthood to midlife. While no further decreases in the percentage slow wave sleep were found as the men aged beyond midlife, the total amount of sleep decreased by nearly a half an hour per decade. The drop in slow wave sleep from young adulthood to midlife accompanied a similar drop in growth hormone levels.

Growth hormone is lipolytic (breaks down fat) and acts to reduce and redistribute body fat. Obesity has been associated with reductions in growth hormone output and treatment of elderly individuals with growth hormone replacement results in increases in lean body mass and decreases in fat mass. While this study does not answer the question directly (whether or not changes in aging sleep patterns are responsible for middle-aged weight gain), the inference is clear. And there is no doubt that poor and inadequate sleep can affect many aspects of your quality of life: athletic performance, work productivity, immune response and well-being. There is, however, much that this study does leave in doubt and much more research is needed to prove a slow wave sleep/body fat connection.

Steps you can take to get a better night's sleep include regular exercise, eliminating stimulants and alcohol, eating smaller meals, having a carbohydrate snack 30 minutes before bed, and keeping regular hours. Slacking on sleep may have ramifications you've never dreamed of--like gaining weight.

(Journal of the American Medical Association, 2000, Vol. 284, No. 7, pp. 861-868: Hormone Research, 2000, Vol. 53. No, 5, pp. 215-220; Clinical Endocrinology, 1993, Vol. 38, No. 1, pp. 63-71)