Higher habitual intake of dietary fat and carbohydrates are associated with lower leptin and higher ghrelin concentrations in overweight and obese postmenopausal women with elevated insulin levels

A highly regulated homeostatic system governs body weight; however, it is possible that this system might be impaired by the sustained intake of highly palatable foods. Short-term feeding studies suggest that the appetite-stimulating hormone ghrelin is suppressed less effectively by dietary fat intake, and diets high in sucrose decrease levels of the adipose hormone leptin. We hypothesized that higher habitual intake of dietary fat and carbohydrate (CHO) would be associated with elevated concentrations of circulating plasma ghrelin and lower circulating leptin in humans, a hormonal profile that could promote weight gain. To test our hypothesis, we examined the cross-sectional associations of ghrelin and leptin with the habitual macronutrient intake of 165 healthy overweight and obese sedentary women and tested the modifying role of insulin in these associations. We observed a significant inverse association between leptin concentrations and percentage energy from CHO independent of body mass index, percentage body fat, age, and intraabdominal fat (β = −0.11 P = .04). No significant associations were observed between ghrelin and macronutrients or their subtypes among the total cohort. Among women with insulin concentrations at or greater than the median, we found a statistically significant positive association between intake of saturated fat and ghrelin concentrations, as well as additional statistically significant associations between leptin concentrations and macronutrients not observed among the total cohort. Our results provide some evidence that diets higher in fat and CHO are associated with a hormonal profile (ie, lower leptin and higher ghrelin concentrations), which could enhance weight gain, particularly among individuals with higher circulating insulin concentrations.