Effects of a high-protein/low carbohydrate versus a standard hypocaloric diet on adipocytokine levels and insulin resistance in obese patients along 9 months

Abstract

Objective: Recent dietary trials and observational studies have focused on the effects of diet on health outcomes such as improvement in levels of surrogate biomarkers. The aim of our study was to examine the changes in weight, adipocytokines levels and insulin resistance after a high-protein/low carbohydrate hypocaloric diet vs. a standard hypocaloric diet during an intervention of 9 months.

Subjects and methods: 331 obese subjects were randomly allocated to one of two diets for a period of 9 months. Diet HP (n=168) (high-protein hypocaloric diet) consisted in a diet of 1050 cal/day, 33% of carbohydrates, 33% of fats and 34% of proteins. Diet S (n=163) (standard protein hypocaloric diet) consisted in a diet of 1093 cal/day, 53% carbohydrates, 27%fats, and 20% proteins.

Results: With the diets HP and S, BMI, weight, fat mass, waist circumference, waist-to-hip ratio, systolic blood pressure, total cholesterol, LDL-cholesterol, insulin and HOMA decreased. The decrease at 9 months of (BMI: -2.6±1.3kg/m(2) vs. -2.1±1.2kg/m(2):p<0.05), weight (-8.4±4.2kg vs. -5.0±4.1kg: p<0.05), fat mass (-5.1±4.1kg vs. -3.4±4.2kg: p<0.05), systolic blood pressure (-5.1±7.1mmHg vs. -3.1±2.1mmHg: p<0.05), (insulin levels -4.0±4.8 UI/L vs. -2.2±2.4 UI/L; p<0.05) and HOMA (-0.8±1.0 units vs. -0.3±1.0 units; p<0.05) was higher in diet HP than Diet S. With both diets, leptin levels decreased.

Conclusion: A high-protein/low carbohydrate hypocaloric diet shows a higher weight loss, insulin and HOMA-R decreased after 9 months than a standard hypocaloric diet. The improvement in adipokine levels was similar with both diets.

Keywords: Adipocytokines; Cardiovascular risk factors; Diet; Insulin resistance; Obesity.