In women with obesity following an 8-week low-calorie diet that includes meal replacements, increasing protein intake or reducing carbohydrate intake does not change the levels of the...
Mechanism
Synthesis from 1 study
When people eat fewer calories, their gut stops releasing as many fullness hormones, no matter if they eat more protein or fewer carbs. This happens because the gut doesn't get enough food to trigger hormone production, so hunger signals stay unchanged.
Most probable mechanism
When the body gets less energy from food, it reduces the release of fullness hormones from the gut, no matter if the diet has more protein or fewer carbs. This happens because the gut cells don't get the usual signals from digested food, so they don't produce as much of these hormones, and the brain doesn't get stronger fullness signals.
Energy restriction reduces luminal nutrient availability in the distal small intestine and colon, decreasing stimulation of enteroendocrine L-cells.
Reduced L-cell stimulation leads to diminished synthesis and secretion of GLP-1 and PYY into the bloodstream.
Lower circulating concentrations of GLP-1 and PYY result in reduced activation of vagal afferents and hypothalamic satiety centers.
Metabolic adaptations such as reduced insulin and glucose fluctuations do not override the suppression of gut hormone release under sustained energy restriction.
Less supported by current evidence, but not ruled out
Eating more protein increases amino acid levels, which keeps glucagon high and lowers taurine, but this does not change the amount of fullness hormones released by the gut.
Increased dietary protein elevates circulating amino acids, stimulating hepatic gluconeogenesis and sustaining glucagon secretion.
Elevated sulfur-containing amino acids increase taurine catabolism, reducing plasma taurine concentrations.
These metabolic shifts occur without altering enteroendocrine L-cell activity or GLP-1 and PYY secretion.
Evidence from Studies
Supporting (1)
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Does a Higher Protein Diet Promote Satiety and Weight Loss Independent of Carbohydrate Content? An 8-Week Low-Energy Diet (LED) Intervention
Contradicting (0)
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