Effect of Protein-Rich Breakfast on Subsequent Energy Intake and Subjective Appetite in Children and Adolescents: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Breakfast has been labeled "the most important meal of the day", especially for children and adolescents. Dietary protein intake may benefit and regulate appetite and energy balance. However, few meta-analyses have been conducted to examine the effect of protein-rich (PR) breakfast on both children and adolescents. This meta-analytic study was conducted to examine the effect of consuming a PR breakfast on short-term energy intake and appetite in children and adolescents. PubMed, Embase, Cochrane Central Register of Controlled Trials, China Biology Medicine disc (CBM), and China National Knowledge Infrastructure (CNKI) were searched for randomized controlled trials (RCTs) published in January 1990-January 2021. The inclusion criteria applied were RCTs in children and adolescents (7-19 year) comparing PR breakfast consumption with normal protein (NP)/traditional breakfast consumption. Finally, ten studies were included in the analysis, eight studies examined the effect of consuming PR breakfast on SEI (n = 824), and nine studies examined the effect on appetite (fullness = 736, hunger = 710). Our meta-analysis using the random-effects model shows that participants assigned to consume PR breakfast had lower SEI (MD, -111.2 kcal; 95% CI: -145.4, -76.9), higher fullness (MD, 7.4 mm; 95% CI: 6.0, 8.8), and lower hunger (MD, -8.5 mm; 95% CI: -9. 7, -7.3) than those assigned to consume NP/traditional breakfast. However, there was considerable inconsistency across the trial results. Our review suggests that the consumption of PR breakfast could be an excellent strategy for weight management by declining SEI and suppressing appetite, and provides new evidence of the relationship between energy balance and obesity. However, since most eligible studies were of low quality, the results ought to be interpreted cautiously.