A Worksite Program for Overweight Middle-Aged Men Achieves Lesser Weight Loss With Exercise Than With Dietary Change

Objective To compare changes in total and regional body composition using dual energy X-ray absorptiometry (DEXA) after subjects lost weight through change in diet or exercise.Design A 12-month, randomized, controlled study of two weight-loss interventions — low-fat diet ad libitum or moderate, unsupervised exercise — in free-living, middle-aged men. Compliance was determined at monthly measurement sessions through food records and activity logs; DEXA scans were performed every 3 months.Subjects/setting Fifty-eight overweight men (mean body mass INDEX=29.0±2.6; mean AGE=43.4±5.7 years) recruited from a national corporation were assigned randomly to diet, exercise, or control groups.Interventions One group reduced dietary fat to 26.4% of energy intake but kept activity unchanged; another group self-selected aerobic exercise (three sessions per week at 65% to 75% maximum heart rate) but kept diet unchanged. A control group maintained weight.Main outcome measures At 12 months, measurements of weight, total and regional fat mass and lean mass, energy intake, and percentage dietary fat; physical activity indexes. Statistical analyses Results were analyzed using paired t tests and analysis of variance.Results Mean weight loss was 6.4±3.3 kg in dieters and 2.6+3.0 kg in exercisers; control subjects maintained weight. DEXA scans revealed that 40% of dieters’ weight loss was lean tissue; more than 80% of weight lost by exercisers was fat. Exercisers maintained limb lean tissue and lost fat mass.Conclusions Greater total weight and lean tissue loss occurred when subjects lost weight through a low-fat diet consumed ad libitum than when subjects participated in unsupervised aerobic exercise. Use of DEXA enabled identification of progressive total and regional changes in fat and lean tissue. J Am Diet Assoc. 1997; 97:37–42.     

Recurrence of Gestational Diabetes

Summary: We conducted a retrospective review of 540 women with gestational diabetes managed by our Service between 1990 and 1996. The aim was to determine the recurrence rate of gestational diabetes and the factors associated with recurrence. Of 117 women who had a subsequent pregnancy, 82 (70%) had a recurrence of gestational diabetes according to criteria where the fasting glucose value ≥ 5.5 and/or 1 hour ≥10.0 and/or 2-hour ≥8.0 mmol/L after a 75 g oral glucose load. The recurrence rate was 62.4% (58), using the criteria of the Australian Diabetes in Pregnancy Society (ADIPS). Older age in both the index and subsequent pregnancy and insulin requirement during the index pregnancy were the strongest predictors for recurrence of gestational diabetes. Non-English speaking country of birth, higher diagnostic glucose tolerance test (GTT) levels, greater prepregnancy BMI and weight gain between pregnancies were also associated with recurrence.