SAN FRANCISCO — Helping patients—even overweight patients—to avoid gaining more weight is an important therapeutic goal by itself, Dr. Robert Baron said at a diabetes update sponsored by the University of California, San Francisco.
“It's very, very hard to get people to lose weight. Therefore, our priority in a large number of our patients should be to prevent further weight gain,” said Dr. Baron, professor of medicine at the university. “In our society, the default position is to gain weight. You need to have a strategy even to maintain your weight, and that's especially true as you age.”
Recent data support the classic goals of being as fit as possible at one's current weight, preventing weight gain, and then considering attempts at weight loss, he emphasized. Being overweight by itself is not necessarily a risk factor for mortality, other data show. The presence or absence of metabolic syndrome plays a key role in level of risk.
A 2005 meta-analysis of three National Health and Nutrition Examination Surveys (NHANES I, II, and III) found no increased risk for mortality in people who fit the conventional definition of overweight for white people—a body mass index of at least 25 kg/m
“This is controversial, but I think it creates a need for some humility and diagnostic uncertainty about people who are overweight,” he added.
Although the prevalence of obesity has been increasing, the mortality risk associated with obesity decreased between the first of the three surveys (NHANES I) and the more recent NHANES III; however, this could be because of methodologic differences.
The presence of metabolic syndrome doubled the risk for mortality in normal-weight people, increased absolute risk of death by about 50% in overweight people, and increased risk of death by 13% in obese people, a separate 2005 study of 19,173 men found.
Patients who are overweight may not be at increased risk if they are metabolically normal, but the presence of metabolic syndrome or other signs of insulin resistance changes the clinical picture.
“Your BMI is your initial screening test, if you will, and evaluation of metabolic syndrome becomes your more accurate, second-level test to sort out which patients in the overweight category and Class I obese [BMI of at least 30 but lower than 35] need more particularly aggressive interventions,” he said.
Eating less and exercising are still the mainstays of weight loss strategies but must be pursued with greater intensity than many people realize if weight loss is to be the result.
Exercise alone won't do it, and casually “watching what you eat” won't work for most patients. Weight loss requires a diet of “low calories, low calories, low calories” that usually must be monitored quantitatively by the dieter, Dr. Baron advised. Combining calorie restriction with exercise and behavioral therapy traditionally offers the best approach.
Patients who do diet and exercise drop a mean of 8% of their original body weight in the first year, although some patients lose more and some gain weight instead, he added.
In addition, patients who have lost weight need a disciplined strategy to maintain that weight loss, data suggest.
Data on 3,000 successful dieters (mostly white women) who enrolled in the National Weight Control Registry and maintained a 30-pound or greater weight loss for 1 year showed three key steps to keeping the pounds off: high levels of physical activity, diets low in fat and high in fiber, and regular self-monitoring of weight.
'In our society, the default position is to gain weight. You need to have a strategy even to maintain your weight.' DR. BARON