Protein Intake & Insulin Action

Overview

The purpose of this proposal is to determine whether dietary protein restriction has beneficial effects on skeletal muscle insulin sensitivity and β-cell function in obese men and women.

Insulin resistance, impaired pancreatic β-cell function, and diabetes are important complications associated with obesity. Although excess energy intake and body fat accumulation are considered the major culprits responsible for obesity-associated metabolic abnormalities, it is possible that insulin resistance and impaired β-cell function are also due to increased dietary protein intake. Protein intake is \~15 to 25% greater in obese than lean adults and exceeds the current Institute of Medicine Recommended Daily Allowance (RDA) of 0.8 g protein/kg body weight by \~75%. An increase in habitual protein intake of only 10 to 40%, assessed using dietary recall methods, been shown to increase the risk of developing diabetes by up to 2.2 fold. Additionally, the ability to stimulate glucose disposal during insulin infusion is reported to be impaired in individuals consuming double the recommended protein intake as part of an isoenergetic diet. However, it is not known whether decreasing protein intake can improve insulin sensitivity and β-cell function in weight-stable, obese individuals. Accordingly, obese men and women will be randomized to 8 weeks of treatment with a weight maintaining diet containing either i) 0.8 g protein/kg body weight (as recommended by the Institute of Medicine; protein restriction group)or ii) 1.4 g protein/kg body weight (control group). All subjects will receive a standardized "base-diet" with or without protein supplementation to avoid potential food selection bias that could confound the results when using high- and low-protein diets.

Conditions

Interventions

Eligibility

Locations (1)

Outcomes