Lifestyle intervention in overweight individuals with a family history of diabetes.

OBJECTIVE: To assess the effect of lifestyle intervention over 2 years on changes in weight, coronary heart disease (CHD) risk factors, and incidence of diabetes in overweight individuals with a parental history of diabetes. RESEARCH DESIGN AND METHODS: Participants (n = 154), who were 30-100% over ideal body weight, had one or both parents with diabetes, and were currently nondiabetic, were randomly assigned to 2-year treatments focused on diet (decreasing calories and fat intake), exercise (goal of 1,500 kcal/week of moderate activity), or the combination of diet plus exercise or to a no-treatment control group. Subjects were reassessed at 6 months, 1 year, and 2 years. RESULTS: At 6 months, the groups differed significantly on measures of eating, exercise, and fitness; weight losses in the diet and diet-plus-exercise groups were significantly greater than in the exercise and control conditions. Weight losses were associated with positive changes in CHD risk factors. After 6 months, there was gradual deterioration of behavioral and physiological changes, so that at 2 years, almost no between-group differences were maintained. Differences between groups in risk of developing diabetes were of borderline significance (P = 0.08). Strongest predictors were impaired glucose tolerance at baseline, which was positively related to risk of developing diabetes, and weight loss from baseline to 2 years, which was negatively related; in all treatment groups, a modest weight loss of 4.5 kg reduced the risk of type 2 diabetes by approximately 30% compared with no weight loss. CONCLUSIONS: Although initially successful, the interventions studied here were not effective in producing long-term changes in behavior, weight, or physiological parameters. However, weight loss from 0 to 2 years reduced the risk of developing type 2 diabetes. Since modest weight loss significantly reduced risk of type 2 diabetes, further research is needed to determine how best to increase the percentage of subjects achieving at least a modest weight loss.

The effects of health beliefs on weight loss in individuals at high risk for NIDDM.

OBJECTIVE: To determine whether perceived risk and other health beliefs held by individuals at high risk for developing NIDDM predict weight loss and behavior change during a behavioral weight loss program to reduce the risk of NIDDM. RESEARCH DESIGN AND METHODS: Health beliefs and objective risk factors for diabetes were examined in 154 overweight men and women with a family history of NIDDM. The effects of these factors on adherence, dietary intake, weight loss, and changes in glucose levels were examined in a subset of 79 of these subjects who participated in a 2-year behavioral weight control program. RESULTS: Those subjects who perceived themselves at highest risk of developing diabetes had a stronger family history of the disease and were more likely to be women than subjects considering themselves at more moderate risk. These participants also rated diabetes as a more serious disease, but were less likely to believe that weight loss would lower their risk. None of these health beliefs were related to attendance at meetings, dietary intake, weight loss, or fasting glucose, but higher perceived seriousness predicted larger reductions in BMI at 1 year. Of the objective risk factors for NIDDM, higher baseline BMI predicted larger weight losses throughout the program, and a stronger family history of diabetes was related to greater weight regain after an initial weight loss. CONCLUSIONS: Perceived risk of developing diabetes and other health beliefs did not predict performance in a behavioral weight loss program. These data suggest that efforts to modify health beliefs by educating high-risk individuals about their risk and benefits of weight loss may not be effective in improving long-term weight loss results.

Accuracy of self-reported exercise and the relationship with weight loss in overweight women.

PURPOSE: The purpose of this study was to compare self-reported exercise to a more objective measurement of exercise (i.e., Tri-Trac Accelerometer) and to assess whether there is a difference in weight loss between individuals who under- and over-report their exercise. METHODS: Fifty overweight females (BMI = 34.0 +/- 4.2 kg.m-2) who were participating in a behavioral weight control program were included in this study. Subjects were randomly assigned to a long-bout or a short-bout exercise condition, with both groups instructed to exercise 30 min.day-1 on 5 d.wk-1 for a period of 20 wk. The long-bout group was to exercise in one continuous session (e.g., one 30-min session per day), whereas the short-bout group was to divide the exercise into multiple 10-min sessions (e.g., three 10-min sessions per day). Subjects recorded their exercise in a daily exercise log and wore a Tri-Trac accelerometer for a 1-wk period to validate self-reported exercise bouts. RESULTS: Results showed that approximately 45% of the women over-reported the amount of exercise that they performed, and this did not differ between the long-bout and short-bout groups. Women who over-reported their exercise had significantly poorer weight loss across the 20-wk program than women who under-reported their exercise (6.3 +/- 3.6 kg vs 9.4 +/- 5.2 kg). CONCLUSIONS: The results of this study suggest that overweight women who over-report their exercise will have poorer weight loss while enrolled in a behavioral weight loss program compared with others enrolled in the program, and the Tri-Trac Accelerometer may be useful in identifying individuals who inaccurately report the amount of their exercise. The ability to classify individuals as either over- or under-reporters of their exercise may be helpful to weight loss therapists and lead to more successful treatment for obesity.

Randomized controlled trial to prevent excessive weight gain in pregnant women.

BACKGROUND: The Institute of Medicine (IOM) recommends that normal-weight women (BMI (body mass index) of 19.8-26.0) gain 25-35 lb (11.4-15.9 kg) during pregnancy, and that overweight women (BMI of 26.1-29.0) gain 15-25 lbs (6.8-11.4 kg). A significant number of normal-weight women and an even greater proportion of overweight women exceed these guidelines, which increases postpartum weight retention and may contribute to the development of obesity. OBJECTIVE: To determine whether a stepped care, behavioral intervention will decrease the percentage of women who gain more than the IOM recommendation. DESIGN: Randomized controlled trial comparing a stepped-care behavioral intervention with usual care. Women (n=120) who had a BMI>19.8, age>18 and <20 weeks gestation were recruited from a hospital-based clinic serving low-income women and randomized by race and BMI category to the intervention or control group. The intervention group received education about weight gain, healthy eating, and exercise and individual graphs of their weight gain. Those exceeding weight gain goals were given more intensive intervention. Women were followed through pregnancy to their first postpartum clinic visit. The main outcome measure was weight gain during pregnancy categorized as above the IOM recommendations vs below or within the IOM recommendations. RESULTS: The intervention significantly decreased the percentage of normal-weight women who exceeded the IOM recommendations (33 vs 58%, P<0.05). There was a non-significant (P=0.09) effect in the opposite direction among overweight women (59% of intervention and 32% of control gained more than recommended). Postpartum weight retention was strongly related to weight gain during pregnancy (r=0.89). CONCLUSIONS: The intervention reduced excessive weight gain during pregnancy among normal weight women.