RANDOMIZED EVALUATION OF A LOW-FAT AB LIBITUM CARBOHYDRATE-DIET FOR WEIGHT-REDUCTION

Restricting dietary fat intake while consuming carbohydrates ad libitu m has recently been promoted as a weight loss regimen. Sixty subjects (52 females and eight males) were randomized to low fat ad libitum car bohydrate (low-fat) or low fat with caloric restriction (low-calorie) behaviour modification treatments. Forty-nine subjects completed the 1 6-20 week programme. Subjects in both groups reported averaging over f ive exercise sessions per week during treatment. The low-calorie group lost significantly more weight (males 11.8 kg, s.d. 6.4; females 8.2 kg, s.d. 4.2) than the low-fat group (males 8.0kg, s.d. 1.3; females 3 .9 kg, s.d. 3.7). Both groups of subjects lost similar amounts of lean body mass. There was significantly greater loss of body fat in the lo w-calorie group. A slight reduction in RMR, adjusted for changes in le an body mass, was observed in both groups. Fat intake was reduced from 90 to 30g per day. Subjects in both groups reduced their total energy intake with the low-calorie group consuming fewer calories per day th an the low-fat group. Both groups showed significant and equivalent im provements in eating habits based on microanalysis of eating diaries. Eating in social situations and emotional eating, however, continued t o cause adherence problems during treatment for both groups. Follow-up data collected 9-12 months after completion of treatment on 65% of th e subjects completing the study showed no significant difference betwe en the two groups in weight losses from baseline (low-fat group 2.6kg; low-calorie group 5.5 kg).