Abstract
Background/objectives Weight-loss maintenance is challenging, and few succeed in the long term. This study aimed to explain how appetite-related hormones, adaptive thermogenesis, perceived hunger and stress influence weight-loss maintenance. Subjects/methods Fifteen adult women (age, 46.3 +/- 9.5 years; BMI, 39.4 +/- 4.3 kg/m(2)) participated in a 24-month intervention, which included 3-5 months total diet replacement (825-853 kcal/d). Body weight and composition (Magnetic Resonance Imaging), resting metabolic rate (indirect calorimetry), and fasting plasma concentration of leptin, ghrelin, glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and growth differentiation factor 15 (GDF-15) were measured at baseline and after weight loss, around 6 months. Perceptions relating to weight-loss maintenance were explored using qualitative interviews. Results Mean (SD) changes in body weight (-13.8 +/- 6.3 kg) and total adipose tissue (-11.5 +/- 4.9 kg) were significant (P < 0.001). Weight loss was associated with a significant reduction in resting metabolic rate (-291 +/- 226 kcal/day, P < 0.001) and adaptive thermogenesis (-150 +/- 162 kcal/day, P = 0.003), reduction in leptin (P < 0.001) and GLP-1 (P = 0.015), an increase in ghrelin (P < 0.001), and no changes in PYY and GDF-15. Weight regain between 6 and 24 months (6.1 +/- 6.3 kg, P < 0.05) was correlated positively with change in GLP-1 (r = 0.5, P = 0.037) and negatively with GLP-1 at baseline (r = -0.7, P = 0.003) and after weight loss (r = -0.7, P = 0.005). Participants did not report increased hunger after weight loss, and stress-related/emotional eating was perceived as the main reason for regain. Conclusions Weight regain is more likely with lower fasting GLP-1 and greater reduction in GLP-1 after weight loss, but psychological aspects of eating behaviour appear as important in attenuating weight-loss maintenance.