Nutrient timing favours ‘with meal’ protein supplementation to aid lean mass gains
The findings contrast to subjects, who took these supplements between meals resulting in a lower change in body weight composition in adults over a period of six weeks or more.
“Consuming protein supplements with meals, rather than between meals, may be a more effective dietary strategy to improve resistance training–induced changes in body composition by reducing fat mass, which may be relevant for adults looking to improve their health status,” said the review team, led by Wayne Campbell, professor and faculty associate at Purdue University.
“Conversely, consuming protein supplements between meals may be more effective at increasing overall body mass.”
Sports nutrition range
The review notes the importance of timing of protein supplementation, depending on the desired body weight and body composition outcome.
Previous evidence has pointed to the consumption of a protein supplement between meals as a factor in decreasing compensatory eating behaviours, thereby increasing energy intakes and body weight.
Equally, consuming a protein supplement twice daily with meals led to complete energetic compensation in adults who performed resistance training, although body composition was not affected,
The range of protein supplements available, which include ready-to-drink, powdered, and solid forms, cater to these requirements marketed to boost desired outcomes such as weight gain, weight loss, and weight management.
Overall, the review included 34 randomised controlled trials with 59 intervention groups all featuring a population of apparently healthy adults with a mean age of group 19 years and over.
Protein supplements (whey, casein, soy, bovine colostrum, and rice) were acceptable if they were isolates, concentrates, or hydrolysates consumed alone or in combination with other nutrients (creatine, amino acids, and carbohydrate) and protein sources.
Of the intervention groups designated as consuming protein supplements with meals vs. between meals, 56% vs. 72% increased their body mass, 94% vs. 90% increased their lean mass, 87% vs. 59% reduced their fat mass, and 100% vs. 84% increased the ratio of lean to fat mass over time, respectively.
Training the key factor?
“Consuming protein supplements either between meals or with meals in combination with resistance exercise training consistently increased lean mass,” the review said.
“This finding suggests that resistance training is a more potent anabolic stimulus than the timing of protein supplementation in relation to meals.”
The review also pointed out that consuming protein supplements while concurrently resistance training created a positive net protein balance.
Two meta-analyses showed that participants who consumed protein supplements while resistance training had greater lean mass than participants consuming a non-protein placebo.
The research team thought that consuming protein supplements with meals might lead to partial meal replacement that would displace the energy that would be consumed otherwise.
The within-meal effects of protein supplementation are consistent with previous observations that adults may fully compensate for the additional energy from protein supplements that are consumed with meals.
“The decrease in fat mass fits within the results of this systematic review, which showed a consistent increase in lean mass and an inconsistent change in body mass. Since lean mass consistently increased and body mass change was inconsistent, it follows that fat mass would decrease,” the team added.
Source: Nutrition Review
Published online ahead of print: doi.org/10.1093/nutrit/nuy012
“Effects of protein supplements consumed with meals, versus between meals, on resistance training–induced body composition changes in adults: a systematic review.”
Authors: Joshua Hudson, Robert Bergia, Wayne Campbell
