Insulin sensitivity is increased and fat oxidation after a high-fat meal is reduced in normal-weight healthy men with strong familial predisposition to overweight

Abstract

OBJECTIVE: To evaluate whether postprandial abnormalities of energy expenditure and/or lipid oxidation are present in healthy, normal-weight subjects with a strong family history of obesity and thus at high risk to become obese. DESIGN: Case–control study. SUBJECTS: A total of 16 young healthy men participated in the study. Eight subjects had both parents overweight (father's and mother's body mass index (BMI) >25 kg/m²) and eight had both parents with normal body weight (father's and mother's BMI2, respectively). The group of subjects with overweight parents was similar to that with normal-weight parents (control group) in terms of BMI (23.71.7 vs 22.71.1 kg/m²) (Ms.d.) and fat-free body mass (FFM) (60.54.9 vs 58.42.0 kg), but was slightly older than the control group (25.43.3 vs 22.72.4 y; Pvs 7.071.56 U/ml; Pvs 1.60.4; Pvs 75.8874.72 mg/kg FFM 8 h; Pvs 163.68108.22 mg/kg FFM 8 h; P<0.05) in the group of subjects with overweight parents. CONCLUSION: Normal-weight subjects with a strong family history of obesity present a reduced lipid oxidation in the postprandial period and a metabolic profile characterized by low plasma insulin levels and the HOMA index, which is compatible with increased insulin sensitivity. These metabolic characteristics may be considered as early predictors of weight gain and are probably genetically determined.