Background Age‐related loss of lean mass, accumulation of visceral adipose tissue (VAT), and insulin resistance place aging adults with obesity at particularly high risk of cardio‐metabolic disease. By reducing insulin demand, carbohydrate (CHO)‐restricted diet patterns that include foods such as whole eggs may promote loss of body fat, specifically from the visceral cavity, without compromising lean mass and improve metabolic health in aging adults with obesity.

Objective The objective of this study was to determine if consumption of an egg‐based lower‐CHO/high‐fat diet (EBD) vs a standard CHO‐based/low‐fat diet (STD) results in loss of total and visceral fat, preservation of lean mass, and improvements insulin resistance and the lipid profile.

Design In a randomized clinical trial, 26 men and women age 60–75yrs. with obesity (BMI 30–40kg/m2) consumed either an EBD (<25:25:>50% energy from CHO:protein:fat) or STD (55:25:20) for 8 weeks. Participants were not asked to restrict total energy intake. The EBD group was provided eggs throughout the study, whereas the STD group was provided breakfast bars to consume. Body composition by DXA, resting energy expenditure (REE) by indirect calorimetry, and insulin, glucose, HOMA‐IR and lipids by fasting blood draw were assessed at baseline and after the 8‐week intervention.

Results Participants lost 11.0% and 2.3% total fat following the EBD and STD diet, resp. (p<0.01 for difference between diets). The EBD group experienced ~3‐fold greater loss in VAT compared to the STD group (−23.3% vs −7.1%, p<0.01 for difference between diets) and greater decrease in HOMA‐IR (p<0.01), whereas there were no significant between‐group differences in change of total lean mass or REE. Among those in the EBD group, there was a significant decrease in triglycerides and increase in HDL.