Weight loss maintenance: determinants of long-term success.

To analyse determinants of long-term weight maintenance we studied energy expenditure, dietary intake, eating behaviour and psychological symptoms of 9 women (SS, BMI = 26.6) who reached their ideal weight during 1985-86 and were still an average 16.2 kg below their original weight in 1993. Controls were 42 obese, non-reducing females (OC, BMI = 34.8). Dietary intake was calculated from four-day food records. Dietary restraint was assessed by the Three-Factor Eating Questionnaire (TFEQ) and symptoms of bulimia or binge eating by Bulimic Investigatory Test, Edinburgh (BITE). Physical exercise was estimated by open interviews, resting metabolic rate (RMR) by indirect calorimetry and body composition by bioelectrical impedance. Psychological characteristics were studied using the Defense Style Questionnaire (DSQ), Beck Depression Inventory (BDI) and Symptom Checklist (SCL-90). SS had lower RMR (1320 kcal vs. 1540 kcal, p = 0.004), lower daily energy intake (1208 kcal vs. 1525 kcal, p = 0.020) and higher scores for dietary restraint (14.6 vs. 8.4, p = 0.002) than OC. Restraint scores correlated negatively with energy intake and RMR in both groups, especially in SS (r = -0.75, p = 0.021 and r = -0.87, p = 0.002, respectively). Attempts to incorporate habitual physical activities to daily life (89% vs. 39%, p = 0.011) and weekly sports hobbies (67% vs. 13%, p = 0.002) were more often reported by SS. The scores of BITE, DSQ, BDI and SCL-90 were within normal range in both groups but SS had higher scores in most measures, especially for anxiety (16.4 vs. 14.3, p = 0.045). In conclusion, long-term maintenance of weight loss was associated with highly restrained eating, regular physical activity, and perhaps with increased anxiety.