Unprocessed red meat in the dietary treatment of obesity: a randomized controlled trial of beef supplementation during weight maintenance after successful weight loss

Abstract

Background Consumption of unprocessed red meat in randomized trials has no adverse effects on cardiovascular risk factors and body weight, but its physiological effects during weight loss maintenance are not known. Objectives We sought to investigate the effects of healthy diets that include small or large amounts of red meat on the maintenance of lost weight after successful weight loss, and secondarily on body composition (DXA), resting energy expenditure (REE; indirect calorimetry), and cardiometabolic risk factors. Methods In this 5-mo parallel randomized intervention trial, 108 adults with BMI 28–40 kg/m2 (45 males/63 females) underwent an 8-wk rapid weight loss period, and those who lost ≥8% body weight (n = 80) continued to ad libitum weight maintenance diets for 12 wk: a moderate-protein diet with 25 g beef/d (B25, n = 45) or a high-protein diet with 150 g beef/d (B150, n = 35). Results In per protocol analysis (n = 69), mean body weight (−1.2 kg; 95% CI: −2.1, −0.3 kg), mean fat mass (−2.7 kg; 95% CI: −3.4, −2.0 kg), and mean body fat content (−2.6%; 95% CI: −3.1, −2.1%) decreased during the maintenance phase, whereas mean lean mass (1.5 kg; 95% CI: 1.0, 2.0 kg) and mean REE (51 kcal/d; 95% CI: 15, 86 kcal/d) increased, with no differences between groups (all P > 0.05). Results were similar in intention-to-treat analysis with multiple imputation for dropouts (20 from B150 compared with 19 from B25, P = 0.929). Changes in cardiometabolic risk factors were not different between groups, the general pattern being a decrease during weight loss and a return to baseline during weight maintenance (and despite the additional mild reduction in weight and fat mass). Conclusions Healthy diets consumed ad libitum that contain a little or a lot of unprocessed beef have similar effects on body weight, energy metabolism, and cardiovascular risk factors during the first 3 mo after clinically significant rapid weight loss.

High‐ and normal‐protein diets improve body composition and glucose control in adults with type 2 diabetes: a randomized trial

“…However, some observational studies have associated red meat consumption with higher risk of T2D, leading to recommendations to limit its consumption [22,23]. Recommendations to limit red meat consumption are based mostly on observational data, whereas findings from randomized clinical trials usually have found a neutral effect of red meat consumption on health outcomes [24][25][26][27][28]. A recent meta-analysis found no differences in most glycemic and insulinemic risk factors associated with T2D when comparing reduced or no red meat diets with diets that contained red meat [29].…”