Dietary protein is necessary for the synthesis of new muscle tissue, and inadequate dietary protein intake results in net muscle loss over time.

Study: Insects are a viable protein source for human consumption: from insect protein digestion to postprandial muscle protein synthesis in vivo in humans: a double-blind randomized trial

This study showed that eating protein from insects builds muscle just as well as drinking milk protein. So yes, you need enough protein to grow muscle — if you don’t get enough, your muscles won’t grow and may shrink over time.

Study: Higher circulating FGF21, lower protein intake, and lower muscle mass: Associations with a higher risk of mortality

People who ate less protein had less muscle, and those with more muscle lived longer. The study shows that not eating enough protein is linked to losing muscle, which can hurt your health over time.

Study: The role of protein quality and amino acid composition in preventing sarcopenia and functional decline in older adults

If you don't eat enough protein, your body can't build or keep muscle, especially as you get older. This study shows older people need a certain amount of protein at each meal to stop losing muscle.

Study: A Muscle-Centric Perspective on Intermittent Fasting: A Suboptimal Dietary Strategy for Supporting Muscle Protein Remodeling and Muscle Mass?

If you don’t eat enough protein throughout the day, especially in small amounts at multiple meals, your body can’t rebuild muscle properly and may start breaking it down instead. The study shows that spreading protein across 3–4 meals helps keep muscle strong.