The effects of whey protein on anthropometric parameters, resting energy expenditure, oxidative stress, and appetite in overweight/obese women with type 2 diabetes mellitus: A randomized placebo controlled clinical trial

Background: Insufficient data are available on the effects of long-term whey protein (WP) consumption on patients with type 2 diabetes mellitus (T2DM). So, in this study, we aimed to examine the effects of WP combined with individualized diet on anthropometric parameters, resting energy expenditure (REE), oxidative stress markers, and appetite among overweight/obese women with T2DM. Methods: In this 3-month double-blind placebo-controlled randomized clinical trial, 48 women with T2DM were randomly allocated into either WP group (one bread fortified by 20 g whey protein concentrates (WPC)) or placebo group (one unfortified bread) along with their individualized diets. At both pre- and post-intervention phases, physical activity, anthropometric parameters, REE, appetite, and serum levels of total antioxidant capacity (TAC) and malondialdehyde (MDA) as well as diet were assessed. Results: Thirty-five patients completed the trial. At the endpoint, there were no significant between-group differences for anthropometric parameters (p > 0.05), except for waist circumference (WC), which was lower in the WP group after adjusting for the confounders (p = 0.040). Serum level of MDA was significantly decreased in the WP group (p = 0.022). There were no significant within- or between-group changes for serum levels of TAC, REE, and appetite sensations (p > 0.05), except for the “hunger”, which was lower in the WP group after adjusting for the confounders (p = 0.045). Conclusion: Regarding significant reduction in WC, serum levels of MDA, and feeling of hunger, consumption of the WPC fortified bread could be beneficial in women with T2DM. Registration Number: IRCT20110123005670N26; Registration date: 2019/01/07.