Lifetime calorie restraint to prevent obesity is the most powerful way to reduce age-related health

University of South Florida researcher Barbara Hansen, PhD, will likely never be invited to talk about weight loss on Oprah. Her message is mundanely common sense, not faddish - she doesn't drop phrases like "low carb," or "low fat," or "geared to your body type" or "put your body into fat-burning mode."

"The fact is that the price of leanness is eternal vigilance - losing and keeping off weight requires a lifelong effort. It amounts to maintaining a constant, realistic balance between total calories consumed and total calories expended," said Dr. Hansen, a physiologist and psychologist specializing in obesity, diabetes and their age-related health complications.

Dr. Hansen, a professor of medicine and pediatrics, directs the USF Health's Center for Preclinical Research, which combines obesity, diabetes and aging research, and the Diabetes Complications Prevention Center. Her latest studies with rhesus monkeys have shown that lifetime calorie restraint to prevent obesity is the most powerful way to reduce age-related health problems such as high blood pressure and high triglycerides and to prevent or delay the progression of insulin resistance toward diabetes.

Monkeys whose food intake was maintained in amounts to assure a constant healthy body weight were not only healthier; on the average they lived longer than their counterparts who ate as much as they wanted.

"Our studies have unequivocally demonstrated that if you prevent excess fat deposits in the body through excess calorie restraint, you'll improve health and postpone death," said Dr. Hansen.

She is quick to point out that scientific evidence does not support assertions that the epidemic of obesity is the fault of the obese themselves or a "toxic" environment that seduces people with super-sized menus and convenience food at every corner. "There's a tendency to enter into a 'blame the patient' approach of 'you did this to yourself and you can fix it,'" Dr. Hansen said. "That's unfair and inappropriate."

There is still much scientists don't know about the complex interaction of genetic and environmental factors that predispose some individuals to obesity while others seem to eat to their heart's content without packing on pounds. Dr. Hansen considers "single cause" hypotheses such as diet composition, inactivity and obesity genes alone as too simplistic. "Obesity is a continuum that develops early or late, quickly or slowly, with a heavy dose of genetic predisposition," she said.

Studies support the concept that each person has an age-related "set" point for weight somehow regulated by physiology and genetics. This may help explain why more than 95 percent of dieters who shed 35 extra pounds or more eventually regain the weight, Dr. Hansen said. "Basically, while your weight may fluctuate throughout life, your body's natural tendency is to return to its individually programmed body composition."