Young, trained men who drink a whey protein shake 5 minutes after lifting weights eat about 430 kJ less at their next meal than when they drink a carbohydrate shake with the same calories, due to...
Mechanism
Synthesis from 1 study
The thick, creamy texture of the whey drink makes you eat slower, giving your body time to feel full before you finish eating as much. This reduces how much you eat later, even though you don’t feel any hungrier or fuller than before.
Most probable mechanism
A thick, creamy drink makes a person eat more slowly because it takes longer to process in the mouth, which gives the body more time to register fullness before consuming the same amount of calories, leading to less food eaten at the next meal.
Whey protein isolate forms a high-viscosity, creamy liquid due to its molecular structure and formulation
Increased oral viscosity prolongs orosensory exposure and increases the duration of mechanical and tactile processing during swallowing
Slower eating rate reduces the rate of nutrient delivery to the gastrointestinal tract and extends meal duration
Extended meal duration allows gut distension and nutrient sensing mechanisms to activate satiety signals before total caloric intake reaches levels that would trigger cessation of eating
Reduced energy intake occurs without changes in subjective hunger or fullness ratings because the sensation of fullness is driven by physical eating pace and oral processing, not by perceived appetite
Less supported by current evidence, but not ruled out
Amino acids from digested whey protein stimulate cells in the gut to release hormones that signal fullness to the brain, which may reduce eating even if the person does not feel consciously hungrier or fuller.
Whey protein is broken down into amino acids in the small intestine
Amino acids activate enteroendocrine cells to release cholecystokinin and glucagon-like peptide-1
These hormones bind to receptors on vagal nerve endings in the gut wall
Vagal signals are transmitted to the brainstem, where they inhibit feeding centers
Food intake decreases without a corresponding change in conscious hunger or fullness perception
Evidence from Studies
Supporting (1)
Community contributions welcome
Whey protein consumption after resistance exercise reduces energy intake at a post-exercise meal
Contradicting (0)
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Gold Standard Evidence Needed
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