Effects of Diet Composition on Postprandial Energy Availability during Weight Loss Maintenance

Carolyn O. Walsh,Henry A. Feldman,Cara B. Ebbeling,Janis F. Swain,David S. Ludwig,Robert L. Markowitz,Susanne Breuer Votruba

doi:10.1371/journal.pone.0058172

Carolyn O. Walsh, Henry A. Feldman + Show 5 more

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https://doi.org/10.1371/journal.pone.0058172

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Abstract

BackgroundThe major circulating metabolic fuels regulate hunger, and each is affected by dietary composition. An integrated measure of postprandial energy availability from circulating metabolic fuels may help inform dietary recommendations for weight maintenance after weight loss.AimWe examined the effect of low-fat (LF, 60% of energy from carbohydrate, 20% fat, 20% protein), low-glycemic index (LGI, 40%–40%-20%), and very low-carbohydrate (VLC, 10%–60%-30%) diets on total postprandial metabolic fuel energy availability (EA) during weight loss maintenance.MethodsEight obese young adults were fed a standard hypocaloric diet to produce 10–15% weight loss. They were then provided isocaloric LF, LGI, and VLC diets in a randomized crossover design, each for a 4-week period of weight loss maintenance. At the end of each dietary period, a test meal representing the respective diet was provided, and blood samples were obtained every 30 minutes for 5 hours. The primary outcome was EA, defined as the combined energy density (circulating level×relative energy content) of glucose, free fatty acids, and β-hydroxybutyrate. Secondary outcomes were individual metabolic fuels, metabolic rate, insulin, glucagon, cortisol, epinephrine, and hunger ratings. Respiratory quotient was a process measure. Data were analyzed by repeated-measures analysis of variance, with outcomes compared in the early (30 to 150 min) and late (180 to 300 min) postprandial periods.ResultsEA did not differ between the test meals during the early postprandial period (p = 0.99). However, EA in the late postprandial period was significantly lower after the LF test meal than the LGI (p<0.0001) and VLC (p<0.0001) test meals. Metabolic rate also differed in the late postprandial period (p = 0.0074), with higher values on the VLC than LF (p = 0.0064) and LGI (p = 0.0066) diets.ConclusionThese findings suggest that an LF diet may adversely affect postprandial EA and risk for weight regain during weight loss maintenance.Trial RegistrationClinicalTrials.gov NCT00315354

Highlights

Circulating levels of the major fuels the body uses for metabolic processes, including glucose, free fatty acids (FFA), and ketones, are tightly regulated by hormonal mechanisms
These findings suggest that an LF diet may adversely affect postprandial energy availability (EA) and risk for weight regain during weight loss maintenance
Many studies have shown that circulating levels of the individual fuels affect appetite [2,3,4,5]. In both rodent [2,3] and human [4] models, hypoglycemia and decreased FFA levels lead to increased food intake

Summary

Introduction

Circulating levels of the major fuels the body uses for metabolic processes, including glucose, free fatty acids (FFA), and ketones, are tightly regulated by hormonal mechanisms. Many studies have shown that circulating levels of the individual fuels affect appetite [2,3,4,5]. In both rodent [2,3] and human [4] models, hypoglycemia and decreased FFA levels lead to increased food intake. Limited data suggest that ketones, such as betahydroxybutyrate (BHB), decrease appetite [5] These studies of individual fuels may not provide a comprehensive view of the metabolic regulation of hunger, because the body can utilize a varying mix of fuels under varying dietary conditions. An integrated measure of postprandial energy availability from circulating metabolic fuels may help inform dietary recommendations for weight maintenance after weight loss

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