Insect protein to support human skeletal muscle anabolism: A systematic review of randomised controlled trials

Context: A global shift towards sustainable food sources is emerging due to the immense environmental pressure from producing animal foods. Insects present a novel source of sustainable dietary protein due to their high protein content and favourable amino acid profile. Objectives: The aim of this systematic review was to establish the effects of insect compared to animal protein on skeletal muscle anabolism and adaptation. This review also aimed to explore the usefulness of insects for supporting the protein needs of population groups with high protein requirements. Data Sources: Database searches were performed using the search terms edible insects and insect protein; plus, key words human health, exercise, anabolic response, muscle protein synthesis, skeletal muscle, muscle adaptation, lean mass, bioavailability. Studies had to be randomised controlled trials using adult human participants (>18 yrs) and measure protein bioavailability, anabolic response, or skeletal muscle adaptation, with direct comparison between insect and animal protein. Data Extraction: Four studies (n = 100 participants) were included in the review. Of the two studies which assessed only postprandial blood amino acid concentration, one reported higher aminoacidemia from cricket compared to beef protein ingestion and the other reported higher aminoacidemia from whey compared to lesser mealworm protein ingestion. Two studies also directly assessed the postprandial skeletal muscle anabolic response following exercise. Both reported lower peak plasma amino acid concentration from cricket or lesser mealworm protein compared to whey or milk protein, but there was no difference in skeletal muscle anabolism between the insect and animal protein sources. Conclusion: Insects are a viable protein source which can likely support skeletal muscle anabolism to the same extent as conventional animal protein but with a considerably lower environmental impact. Insects could be an effective protein source to facilitate skeletal muscle during challenging life circumstances or physically demanding occupations.