Daily consumption of 10 grams of lupin protein for five weeks reduces fasting glucose and C-peptide levels and lowers glucose-dependent insulinotropic polypeptide (GIP) and ghrelin concentrations in adolescent boys with overweight or obesity.

Lupin protein feeds beneficial gut bacteria that make butyrate, a compound that tightens the gut lining and stops inflammatory molecules from entering the blood. This reduces inflammation in fat tissue, which lets insulin work better. At the same time, lupin protein directly signals the gut to release less of the hunger hormone ghrelin and less of the insulin-stimulating hormone GIP. With less GIP, the pancreas doesn't need to produce as much insulin, so blood sugar drops. With less ghrelin, hunger decreases. Together, these changes lower fasting glucose and insulin levels.