Effects of a 6-Month Lifestyle Intervention for Type 2 Diabetes Featuring Intermittent Energy Restriction or Time-Restricted Eating on Dietary Intake

Introduction and Objective: Time-restricted eating (TRE) and intermittent energy restriction (IER) may be particularly effective in patients with type 2 diabetes mellitus (T2DM), but their effects on achieving dietary change recommendations for T2DM have not been assessed in a parallel trial. Methods: This RCT enrolled 57 adults with type 2 diabetes and overweight/obesity (21-65 years old, HbA1c 6.7-9.5%, BMI 25-45 kg/m²) to participate in a 6-month intervention featuring IER or TRE with energy restriction (TRE+ER). TRE+ER adhered to a ≤8-hour eating window ≥5 days/week and reduced energy intake during the first 3 months. IER utilized 2-3 very low-calorie diet days/week during the weight loss phase (0 - 3 months) and as often as needed during weight maintenance (3 - 6 months). Assessments occurred at baseline, 3- and 6-months of a comprehensive lifestyle intervention featuring regular group meetings to facilitate behavior change. Five days of dietary intake data was prospectively collected using the Remote Food Photography Method and analyzed using Nutrition Data Systems for Research (2021). Health Eating Index (HEI-2020) scores were calculated to assess diet quality. Results: 53 participants had complete and valid diet records (86% IER, 100% TRE+ER). Both interventions significantly reduced energy (IER: -366.09 kcal [-547.06, -185.13]; TRE+ER: -408.27 [-569.74, -246.81]), total fat (IER: -21.04 g [-33.43, -8.66]; TRE+ER: -30.89 g [-41.67, -20.12]), and total carbohydrate intake (IER: -45.54 g [-60.98, -30.10]; TRE+ER: -28.42 g [-54.18, -2.66]) relative to baseline, with no significant differences between groups. Diet quality as measured by HEI increased in both IER (13 [7, 19]) and TRE+ER (13 [8, 18]). Conclusion: IER and TRE+ER significantly reduced energy intake, improved diet quality, and altered macronutrient distribution in individuals with T2DM. Both strategies were effective in achieving dietary change recommendations for type 2 diabetes. Disclosure: H. Lackey: None. C.K. Martin: Advisory Panel; EHE Health, Wondr Health. Other Relationship; Academy of Nutrition and Dietetics, ABGIL. Research Support; Foundation for Food and Agriculture Research; Kroger Co. Zero Hunger / Zero Waste Foundation, Weight Watchers International, Eli Lilly and Company. Other Relationship; The Bray Course Planning Committee, Spoonified. J.P. Thyfault: None. J. Donnelly: None. K. Grdinovac: Consultant; AmalgamRx. R. Montgomery: None. L. Clark: None. F. Steger: None. Funding: American Diabetes Association (7-22-JDFN-13); National Institutes of Health (5P20GM144269)