In women with obesity, lowering carbohydrate intake from 40% to 28% of total calories increases fullness after meals, but does not result in eating fewer calories overall or losing more weight.
Mechanism
Synthesis from 1 study
Eating fewer carbs makes blood sugar and insulin rise less after a meal, which tells the brain you're full. It also causes the body to make small amounts of ketones that further reduce hunger. But even though you feel fuller after eating, you still eat the same amount of food all day and don't lose...
Most probable mechanism
When someone eats fewer carbs, their blood sugar and insulin don't spike as much after eating. This change tells the brain they are full, so they feel less hungry right after the meal. At the same time, the body starts making small amounts of ketones, which also signal the brain to reduce hunger. But even though they feel fuller after eating, their total food intake over the day stays the same, and they don't lose more weight.
Reduced dietary carbohydrate intake lowers postprandial glucose and insulin concentrations in the bloodstream.
Lower insulin and glucose levels reduce stimulation of hunger-promoting neural circuits in the hypothalamus and enhance signaling from satiety-associated brain regions.
Metabolic adaptation to reduced carbohydrate availability increases hepatic ketone body production, even without full ketosis.
Ketone bodies cross the blood-brain barrier and directly suppress activity in appetite-stimulating neurons in the hypothalamus.
Enhanced postprandial satiety signaling does not alter total daily food intake or energy expenditure.
Less supported by current evidence, but not ruled out
Eating more protein increases amino acids in the blood, which causes the liver to release more glucagon and reduces taurine levels. These changes support sugar production in the liver but do not change how much a person eats or how much weight they lose.
Increased dietary protein intake elevates circulating amino acid concentrations.
Elevated amino acids blunt the suppression of glucagon secretion during energy restriction.
Glucagon stimulates hepatic gluconeogenesis to maintain blood glucose levels.
Increased sulfur amino acid metabolism reduces plasma taurine concentration.
These metabolic shifts do not alter daily energy intake or body weight.
Evidence from Studies
Supporting (1)
Community contributions welcome
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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