metabolism
Gluconeogenesis
The body's production of glucose from non-carbohydrate sources such as amino acids and glycerol — a demand-driven backup fuel supply.
Gluconeogenesis (GNG) lets the liver and kidneys manufacture glucose from lactate, glycerol, and glucogenic amino acids when dietary carbohydrate is scarce, keeping blood sugar stable during fasting, sleep, and low-carb or ketogenic diets. Crucially, GNG is demand-driven, not supply-driven: eating more protein does not force extra glucose production or "kick you out of ketosis" at normal intakes (1.6–2.0 g/kg). The process is regulated by insulin, glucagon, and cortisol rather than by protein availability.
Primary Sources
- Rui L. "Energy metabolism in the liver." Compr Physiol. 2014.
- Fromentin C et al. "Dietary proteins contribute little to glucose production, even under optimal gluconeogenic conditions in healthy humans." Diabetes. 2013.