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Background: Emerging research suggests that redistributing total protein intake from 1 high-protein meal/d to multiple moderately high-protein meals improves 24-h muscle protein synthesis. Over time, this may promote positive changes in body composition. Objective: We sought to assess the effects of within-day protein intake distribution on changes in body composition during dietary energy restriction and resistance training. Design: In a randomized parallel-design study, 41 men and women [mean ± SEM age: 35 ± 2 y; body mass index (in kg/m 2 ): 31.5 ± 0.5] consumed an energy-restricted diet (750 kcal/d below the requirement) for 16 wk while performing resistance training 3 d/wk. Subjects consumed 90 g protein/d (1.0 ± 0.03 g · kg -1 · d -1 , 125% of the Recommended Dietary Allowance, at intervention week 1) in either a skewed (10 g at breakfast, 20 g at lunch, and 60 g at dinner; n = 20) or even (30 g each at breakfast, lunch, and dinner; n = 21) distribution pattern. Body composition was measured pre- and postintervention. Results: Over time, whole-body mass (least-squares mean ± SE: -7.9 ± 0.6 kg), whole-body lean mass (-1.0 ± 0.2 kg), whole-body fat mass (-6.9 ± 0.5 kg), appendicular lean mass (-0.7 ± 0.1 kg), and appendicular fat mass (-2.6 ± 0.2 kg) each decreased. The midthigh muscle area (0 ± 1 cm 2 ) did not change over time, whereas the midcalf muscle area decreased (-3 ± 1 cm 2 ). Within-day protein distribution did not differentially affect these body-composition responses. Conclusion: The effectiveness of dietary energy restriction combined with resistance training to improve body composition is not influenced by the within-day distribution of protein when adequate total protein is consumed. This trial was registered at clinicaltrials.gov as NCT02066948., (© 2017 American Society for Nutrition.)

Context: A preponderance of evidence supports the beneficial effects of whey protein (WP) supplementation on body composition in men; however, there is currently insufficient evidence to make an equivalent claim in women. Objective: This systematic review and meta-analysis assessed the effects of WP supplementation with or without energy restriction (ER) and resistance training (RT) on changes in body mass, lean mass, and fat mass in women. Data Sources: Pubmed, Scopus, Cochrane, and CINAHL were searched using the keywords "whey protein," "body composition," and "lean mass." Data Extraction: Two researchers independently screened 1845 abstracts and extracted 276 articles. Thirteen randomized controlled trials with 28 groups met the inclusion criteria. Results: Globally, WP supplementation increased lean mass (WMD, 0.37 kg; 95% confidence interval [CI], 0.06 to 0.67) while not influencing changes in fat mass (-0.20 kg; 95%CI, -0.67 to 0.27) relative to non-WP control. The beneficial effect of WP on lean mass was lost when only studies with RT were included in the analysis (n=7 comparisons; 0.23 kg; 95%CI, -0.17 to 0.63). The beneficial effect of WP on lean mass was more robust when only studies with an ER component were included (n=6 comparisons; 0.90 kg; 95%CI, 0.31 to 1.49). There was no effect of WP on lean mass in studies without ER (n=9 comparisons; 0.22 kg; 95%CI, -0.12 to 0.57). Conclusion: Whey protein supplementation improves body composition by modestly increasing lean mass without influencing changes in fat mass. Body composition improvements from WP are more robust when combined with ER . [ABSTRACT FROM AUTHOR]

Context: The impact of timing the consumption of protein supplements in relation to meals on resistance training-induced changes in body composition has not been evaluated systematically. Objective: The aim of this systematic review was to assess the effect of consuming protein supplements with meals, vs between meals, on resistance training-induced body composition changes in adults. Data Sources: Studies published up to 2017 were identified with the PubMed, Scopus, Cochrane, and CINAHL databases. Data Extraction: Two researchers independently screened 2077 abstracts for eligible randomized controlled trials of parallel design that prescribed a protein supplement and measured changes in body composition for a period of 6 weeks or more. Results: In total, 34 randomized controlled trials with 59 intervention groups were included and qualitatively assessed. Of the intervention groups designated as consuming protein supplements with meals (n = 16) vs between meals (n = 43), 56% vs 72% showed an increase in body mass, 94% vs 90% showed an increase in lean mass, 87% vs 59% showed a reduction in fat mass, and 100% vs 84% showed an increase in the ratio of lean mass to fat mass over time, respectively. Conclusions: Concurrently with resistance training, consuming protein supplements with meals, rather than between meals, may more effectively promote weight control and reduce fat mass without influencing improvements in lean mass. [ABSTRACT FROM AUTHOR]

There is a shift in thinking about dietary protein requirements from daily requirements to individual meal requirements. Per meal, stimulation of muscle protein synthesis has a saturable dose relationship with the quantity of dietary protein consumed. Protein intake above the saturable dose does not further contribute to the synthetic response; the "excess" amino acids are predominantly oxidized. Given that daily dietary protein intake is finite, finding protein distribution patterns that both reduce amino acid oxidation and maximize their contribution towards protein synthesis (in theory improving net balance) could be "optimal" and is of practical scientific interest to promote beneficial changes in skeletal muscle-related outcomes. This article reviews both observational and randomized controlled trial research on the protein distribution concept. The current evidence on the efficacy of consuming an "optimal" protein distribution to favorably influence skeletal muscle-related changes is limited and inconsistent. The effect of protein distribution cannot be sufficiently disentangled from the effect of protein quantity. Consuming a more balanced protein distribution may be a practical way for adults with marginal or inadequate protein intakes (<0.80 g·kg−1·d−1) to achieve a moderately higher total protein intake. However, for adults already consuming 0.8–1.3 g·kg−1·d−1, the preponderance of evidence supports that consuming at least one meal that contains sufficient protein quantity to maximally stimulate muscle protein synthesis, independent of daily distribution, is helpful to promote skeletal muscle health. [ABSTRACT FROM AUTHOR]

Unhealthy Western-style eating patterns (WSEP) predominate, adversely affecting health. Resistance to improving dietary patterns prompts interest to incorporate a potentially health-promoting ingredient into typical WSEP foods and beverages. We assessed the effect of incorporating isocalorically matched carbohydrates versus milk protein isolate (MPI) into a WSEP on weight loss-induced changes in cardiometabolic health and body composition. In a randomized, double-blind, parallel-design study, 44 participants (age 52 ± 1 years, body mass index (BMI) 31.4 ± 0.5 kg/m2, mean ± standard error) consumed a weight maintenance WSEP (0.8 g total protein/kg/day) for 3 weeks (baseline). After, participants consumed an energy-restricted (750 kcal/day below estimated requirement) WSEP for 16 weeks, randomly assigned to contain either an additional 0.7 g carbohydrate/kg/d (CON: n = 23, 0.8 g total protein/kg/day) or 0.7 g protein/kg/d from MPI (MPI: n = 21, 1.5 g total protein/kg/day) incorporated into foods and beverages. Compared to CON, the MPI favored reductions in average 24 h and sleeping systolic and diastolic blood pressures (BP), waking hours systolic BP, and fasting plasma triglyceride concentrations. Reductions in fasting plasma insulin, glucose, total cholesterol, and low-density lipoprotein cholesterol concentrations were not different between groups. Among all participants, whole body mass, lean mass, fat mass, and thigh muscle area, each decreased over time. For adults finding it difficult to deviate from a WSEP, replacing a portion of their carbohydrate with foods and beverages containing MPI may be an effective dietary strategy to reduce BP after weight loss. [ABSTRACT FROM AUTHOR]