Effect of a Whey Protein Supplement on Preservation of Fat Free Mass in Overweight and Obese Individuals on an Energy Restricted Very Low Caloric Diet

Abstract

The obesity epidemic has caused a widespread interest in strategies to achieve a healthy “high quality” weight loss, where excess fat is lost, while fat free mass (FFM) is preserved. In this study, we aimed to examine the effect of whey protein supplementation given before night sleep on FFM preservation during a 4-week (wk) period on a very low caloric diet (VLCD). Twenty-nine obese subjects (body mass index (BMI) > 28 kg/m2) completed a 4-week intervention including a VLCD and a walking program (30 min walking × 5 times per week). Subjects were randomly assigned to either control (CON, n = 15) or a whey protein supplement (PRO, 0.4 g protein/kg/day, n = 14), ingested before bedtime. Body composition (dual-energy X-ray absorptiometry, DXA), blood analysis and physical test were performed pre and post intervention. We measured nitrogen excretion in three 24 h urine collections (Day 0, 7 and 28) to assess nitrogen balance. Changes in nitrogen balance (NB) after 7 and 28 days was different between treatment groups (interaction p < 0.05). PRO was in NB after 7 days and in positive NB at day 28. In contrast, CON was in negative NB at day 7, but in NB at day 28. Nevertheless, no significant group differences were observed in the change in pre- and post-FFM measurements (−2.5 kg, [95% CI: 1.9; 3.1], p = 0.65). In conclusion, ingestion of a whey protein supplement before bedtime during a 4-week period on a VLCD improved nitrogen balance, but did not lead to any significant improvement in the quality of the weight loss in regard to observed changes in body composition and health parameters compared with controls.

Protein, amino acids and obesity treatment

“…In this population, whey protein supplementation improved waist circumference, blood pressure, and lipid or sugar plasmatic levels, despite heterogeneity in protein doses, BMI, age and follow up duration [25]. Additional studies on body composition showed fat free mass stayed similar for obese adults when adding whey protein supplementation to a four-week long, very low calorie diet and exercise intervention, albeit the statistical power for this study was insufficient with approximately 15 participants per group [26]. In another study by Giglio and colleagues, 52 obese women were randomized and supplemented with either whey protein or hydrolyzed collagen as an afternoon snack for 8 weeks [27].…”

The Effects of Very Low Energy Diets and Low Energy Diets with Exercise Training on Skeletal Muscle Mass: A Narrative Review

“…The current evidence concerning the effects of additional protein supplementation in the context of VLED has to date yielded conflicting results. In 2018, Larsen et al conducted an RCT assessing the effects of additional daily protein supplementation (0.4 g/kg/day) with 30 min of aerobic exercise training (AET) five times per week in 29 patients aged between 18 to 55 years who were either overweight or obese over a 4-week duration [ 58 ]. The authors of this study noted no statistically significant improvements in LBM retention during this period between the protein supplementation and placebo groups [ 58 ].…”

“…In 2018, Larsen et al conducted an RCT assessing the effects of additional daily protein supplementation (0.4 g/kg/day) with 30 min of aerobic exercise training (AET) five times per week in 29 patients aged between 18 to 55 years who were either overweight or obese over a 4-week duration [ 58 ]. The authors of this study noted no statistically significant improvements in LBM retention during this period between the protein supplementation and placebo groups [ 58 ]. In contrast to these findings, Johansson et al (2017) performed a systematic review and meta-analysis of 27 RCT studies, where 6 of these studies had intervention arms that utilised a high protein intervention with a total sample size of 865 [ 59 ].…”

Comparative Meta-Analysis of the Effect of Concentrated, Hydrolyzed, and Isolated Whey Protein Supplementation on Body Composition of Physical Activity Practitioners

“…Whey protein has high concentration of essential amino acids such as leucine [4] and, in addition, its serum proteins are also source of bioactive peptides that can act in the treatment of clinical outcomes such as cancer, HIV infection, hepatitis B, cardiovascular diseases, and osteoporosis [2,3].…”

“…Although the positive effects of the dose/response relationship between WP supplementation and improvement of body composition are already known, factors such as level, type of physical activity and trainability aspects have strong influence on individual final results [11]. Moreover, it is necessary to consider that the maximum saturation dose for the plateau is still uncertain, which makes establishing prevalence values for the risks associated with its continuous long-term ingestion impossible [2,4,6].…”