The dangerous diabetes/obesity connection: how to reduce your risk now.

Considering the growing number of overweight and obese people in this country, it's not surprising that the rate of diabetes is also on the rise. What's the connection between the two? What factors make you more likely to become overweight? And most important, what kinds of changes can you make to your lifestyle to reach and maintain a healthy weight and reduce your ride of developing diabetes?

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You're no doubt familiar with the growing problem of obesity in the United States. According to recent statistics from the U.S. Centers for Disease Control, an estimated 30 percent (60 million) of Americans are obese, and a total of 65 percent (130 million) are overweight or obese. If you're in this segment of society, you're at increased risk of developing a number of diseases including cardiovascular disease, hypertension, some cancers, and diabetes.

The diabetes/obesity connection has more to do with the location of someone's fat stores than simply being overweight, says Osama Hamdy, M.D., Ph.D., an obesity researcher at Joslin Diabetes Center in Boston, Massachusetts. "The problem is central weight gain," he says. "The fat inside the abdomen--the intra-abdominal fat or visceral fat--works like an endocrine gland. It secretes hormones and other chemicals called cytokines, some of which start a process of inflammation in the body." This chronic inflammation causes damage, making the body more resistant to insulin and speeding up the process of atherosclerosis (hardening of the arteries) and coronary artery disease.

The Real Culprit

While researchers used to think that people who were prone to diabetes had insulin deficiency--or experienced a total lack of insulin--they now know that these people produce too much insulin.

Insulin transports the energy produced by the food you eat to your cells. "When you eat a meal, insulin levels go high in order to stimulate the transport," explains Mark Mengel, M.D., M.P.H., chair of community and family medicine at Saint Louis University. "But the chemicals that the abdominal fat secretes interferes with that process, so insulin levels have to go higher than normal, meaning your body has to work harder to transport and store those nutrients."

As this process continues over time, your body's blood sugars begin to rise because the insulin isn't working as well as before--and you develop diabetes.

"This becomes a closed loop," reports Dr. Hamdy. "When that insulin level is high, those people become extremely insulin resistant. If you ask the pancreas to secrete even more insulin, the body will become even more insulin resistant. Insulin is a growth hormone, which means people will gain more weight, and as they gain more weight, they need more insulin, and they become more insulin resistant."

Factors That Make Us Fat

While not every obese person carries a lot of visceral fat, most have a significant amount. Your ethnic background may also play a role. For example, Asian-Americans, Indian-Americans, and Hispanic-Americans tend to add visceral fat when they gain even a small amount of weight.

That's why Americans aren't just getting fatter; they're getting rounder, too. "They're mostly gaining weight in their central area," says Hamdy. "Between 1994 and 2000, the average waist of an American man increased 1.1 inches, and the average waist of a woman shot up 1.3 inches."

So, what's making us gain weight? There are two primary factors at play--eating too much and exercising too little. "Forty percent of people are sedentary, and that decreases the metabolic rate. You need even fewer calories to maintain your body weight," says Mengel.

In suburban areas people are more reliant on automobiles to get around, and fewer of us walk to work or "run" errands. People are also more likely to spend time in front of the television or computer and less likely to be engaging in outdoor activities.

More Affluence

"We have more affluence than we have ever had in world history, which allows us to do things we couldn't do before such as drive cars everywhere we go, use escalators, and depend on remote-control devices along with other labor-saving inventions," says Steve Aldana, Ph.D., professor of lifestyle medicine at Brigham Young University in Provo, Utah. "Physical labor has all but been removed from our society. Rather than being craftsmen and tradesmen and farmers, for the most part we're all making our living sitting down--except for manual laborers. So, our environment in that regard has changed."

The lack of activity starts early. Many schools no longer require physical education for students, and some are eliminating recess as well. Then there's the matter of eating too much. "We now have more disposable income, we tend to eat out more, and food-serving sizes are through the roof," says Aldana. "Food is inexpensive, convenient, tastes great, and it comes in enormous sizes."

Age is another factor for central weight gain. As you get older, your body produces smaller amounts of sex hormones (testosterone in men, estrogen, progesterone, and small amounts of testosterone in women), which increases your risk of abdominal obesity.

And finally, stress is contributing to the problem as well. "Once you're stressed, there are a lot of stress hormones such as cortisol, adrenaline, and others flooding your system," adds Hamdy. "They play a major role in weight gain as well."

Time for Change

While there are many factors increasing your risk of obesity, there's also much you can do to reduce your risk of becoming overweight and developing diabetes.

* Eat less, but don't slash your caloric intake. "Eat enough calories to maintain a healthy body weight. That helps you lose weight if you are obese," says Hamdy. "Starvation diets have been shown not to work in the long run." If you need to lose weight, ask your doctor about the appropriate number of calories you need to maintain a healthy body weight, and adjust your intake accordingly.

* Combine diet with exercise. Exercise helps boost your metabolic rate, so you burn more calories. It's an important component of any weight-loss plan, especially when you want to reduce your risk of diabetes. A recent study revealed that people who cut their intake by 2,000 calories but didn't exercise, didn't lose as much visceral fat as those who added a 2,000 calorie-burning activity to their weight-loss program.

"Visceral fat is very sensitive to exercise and it goes down quickly within a short period of time," states Hamdy. "Most people get the benefit within the first couple of weeks." In fact, recent research shows that losing only a small amount of body weight (5-10 percent) can significantly improve your insulin sensitivity. This means a lot of diabetes--in its early stages--can be reversed if people simply lose weight, he says.

* Skip fast food. It's high in fat and calories, and the portion sizes tend to be enormous. Limit or eliminate soda, juice, and sugary coffee drinks. Most people don't realize how many calories they're consuming in such beverages. One survey of more than 50,000 nurses found that the more sugar-sweetened soda they drank, the more likely they were to develop diabetes.

* Set a good example. Want your kids to embrace a healthier lifestyle? Then show them how it's done. "Kids are going to do exactly as their parents do, so if Junior is gaining weight and is sedentary, it's because he's probably in an environment where his parents are also sedentary and eating large amounts of poor-quality food," says Aldana. "It's going to start with Mom and Dad and if they don't change, Junior won't either." Also, model an active lifestyle by taking a walk together after dinner, going for a bike ride as a family, or regularly playing catch or basketball in the backyard.

* Clear your cabinets. Get rid of junk foods like chips, cookies, and candy; and make room for healthier snacks such as fresh fruit, pepper strips, baby carrots with hummus, or low-fat yogurt with whole-grain cereal. You can't snack on junk that's not there, and you and your family will more likely eat the good stuff when it's readily available.

* Cut back on the tube. Studies show that the more television you watch, the more likely you are to be overweight. You can still enjoy your favorite program, but get in the habit of keeping your set off most of the time. If you're bored, take up a new hobby, sign up for a class, or launch that long-neglected home-improvement project.

* Lace up your walking shoes. Doctors insist that walking isn't just a good exercise; it's the best exercise. Even regular strolls around your neighborhood can pile on the health benefits. "Some people have the perception that they need to go to the gym or have a personal trainer or fancy equipment to use [to get fit] but the type of activity or location doesn't matter," says Aldana. "It's just a matter of moving around, and that includes simple day-to-day activities such as working in the garden, mowing the yard, walking during lunchtime, and using stairs instead of elevators. All of those are forms of physical activity that count. They're all forms of expending energy."

* Start slow, aim high. The recommendation for good health is now 60 minutes of moderate intensity activity most days of the week. If you've been inactive, start off with five- to 10-minute sessions of walking and gradually build your endurance and strength. Include strength training and stretching exercises and you'll get stronger and more fit as you reduce your risk both of obesity and diabetes.

Kelly James-Enger is the coauthor of Small Changes, Big Results: A 12-Week Action Plan to a Better Life (Random House, 2005). She writes from Downers Grove, Illinois.