Effects of a High Protein/Low Carbohydrate Versus a Standard Hypocaloric Diet on Weight and Cardiovascular Risk Factors, Role of a Lys656asn Polymorphism of Leptin Receptor Gene

Background: The SNP of the leptin receptor (Lys656Asn) has been related with metabolic parameters. The aim of our design was to evaluate the influence of Lys656Asn variant of Leptin receptor gene on weight loss and metabolic parameters secondary to a high protein/low carbohydrate vs. a standard hypocaloric diets. Design: A total of 280 obese subjects were randomly allocated to one of two diets during 9 months (Diet HP (high protein-low carbohydrate hypocaloric diet) and Diet S (standard protein hypocaloric diet)). Results: After both diets and in both genotypes, body mass index (BMI), fat mass, weight, systolic blood pressure and waist circumference decreased, without differences between both diets. With the diet type HP and in both genotypes, triglycerides decreased. In subjects with Lys656Lys genotype, glucose, insulin levels, HOMA-R, total cholesterol and LDL- total cholesterol decreased after HP diet. No statistical changes were detected in Asn allele carriers. After diet S and in patients with Lys656Lys genotypes, only total cholesterol, triglycerides and LDL- total cholesterol decreased, without changes in Asn allele carriers. Conclusion: Obese subjects with Asn656 allele have a different metabolic response than Lys656Lys genotype subjects, secondary to the same weight loss with two different hypocaloric diets.