Protein triggers insulin, but differently than carbohydrates—through direct amino acid stimulation, not blood sugar spikes. Research by Holt on the insulin index shows protein-rich foods stimulate significant insulin despite low carb content. Protein also triggers glucagon, which partially offsets insulin’s effects. Fat has minimal insulin impact. The result: protein causes a more moderate, balanced hormonal response supporting satiety and muscle preservation.
This companion covers carbs and insulin, protein and insulin, fat and insulin, and practical implications for meal design. (3 min read)