Replacement of dietary fat by sucrose or starch: Effects on 14 d ad libitum energy intake, energy expenditure and body weight in formerly obese and never-obese subjects

OBJECTIVE: To investigate the impact of a high-sucrose diet vs a high-starch and a high-fat diet on 14 d ad libitum energy intake, body weight, energy expenditure and sympathoadrenal activity. MEASURMENTS: Food intake; body weight and composition (bioelectrical impedance); 24 h energy expenditure, substrate oxidation rates, spontaneous physical activity, heart rate and appetite sensations in a respiration chamber (VAS scores); plasma catecholamine concentration and blood pressure. SUBJECTS: Twenty normal-weight, healthy women, 9 post-obese (body mass index (BMI): 22.9±0.7 kg/m²) and 11 closely matched controls (BMI: 22.6±0.4 kg/m²). RESULTS: Average 14 d ad libitum energy intake was 13% and 12% lower on the starch diet compared with the sucrose and fat diets, respectively (P<0.05). In both post-obese and normal-weight subjects, body weight and fat mass decreased significantly on the starch diet (by 0.7±0.2 kg and 0.4±0.1 kg, respectively, P<0.05). No changes were observed on the fat or sucrose diets. After 14 d on the sucrose diet, 24 h energy expenditure as well as postprandial plasma adrenaline and noradrenaline concentrations, were significantly increased compared with the other two diets. Overall satiety and palatability ratings were also highest on the sucrose diet. CONCLUSION: Intake of a 14-d ad libitum high-starch diet decreased energy intake and body weight compared with a high-fat or high-sucrose diet. The increased energy expenditure observed on the sucrose-rich diet can probably be explained both by the increased intake of energy and fructose (mainly from sucrose) on this diet.