Diet Quality following Total Meal Replacement Compared with Food-Based Weight-Loss Diets in Postmenopausal Women with Obesity: A Secondary Analysis of the TEMPO Diet Trial

Background Severely energy-restricted diets that utilize meal-replacement products are the most effective dietary treatment for obesity. However, there are concerns they may fail to educate individuals on how to adopt a healthy food-based diet after weight loss. Objectives The aim of this research was to compare changes in diet quality following total meal replacement compared with food-based weight-loss diets. Methods In this secondary analysis of a randomized controlled trial, 79 postmenopausal women aged 45-65 y, with a BMI (in kg/m2) of 30-40, were randomly assigned to either a total meal-replacement diet (energy intake restricted by 65-75% relative to requirements) for 16 wks, followed by a food-based diet (energy intake restricted by 25-35% relative to requirements) until 52 wks, or the food-based diet for the entire 52-wk period. Diet quality was scored at baseline and 52 wks using the Healthy Eating Index for Australian Adults, with score changes compared between groups using an independent t test. Results Diet quality improved from baseline in both groups, but less so in the total meal-replacement group, with a mean (SD) increase of 3.6 (10.8) points compared with 11.8 (13.9) points in the food-based group, resulting in a mean between-group difference of -8.2 (P = 0.004; 95% CI: -13.8, -2.7) points. This improvement in diet quality within both groups was mostly driven by a reduction in the intake of discretionary foods. Intake remained below the recommendations at 52 wks for 4 of the 5 food groups in both dietary interventions. Conclusions In postmenopausal women with obesity, weight-loss interventions that involve either a total meal-replacement diet or a food-based diet both improve diet quality, however, not sufficiently to meet recommendations. This highlights the importance of addressing diet quality as a part of all dietary weight-loss interventions. This trial is registered with the Australia and New Zealand Clinical Trials Registry as 12612000651886.