Obese adults who eat high-protein diets have lower triglycerides, lower total cholesterol, lower LDL cholesterol, and stable HDL cholesterol compared to those who do not.
Mechanism
Synthesis from 1 study
Eating more protein tells the liver to make less fat and fewer fat-carrying particles, which lowers bad cholesterol and triglycerides. It also makes you feel fuller and burns more calories, helping you lose fat. The good cholesterol stays the same because the body doesn't break down muscle, which...
Most probable mechanism
Eating more protein lowers the liver's production of fat-carrying particles called VLDL, which reduces bad fats in the blood. The liver makes less fat from scratch because protein intake shifts metabolism away from storing fat. This causes triglycerides and LDL cholesterol to drop, while the good cholesterol stays stable because the body clears fat more efficiently and doesn't break down muscle tissue.
Dietary protein increases amino acid delivery to the liver, suppressing de novo lipogenesis and fatty acid esterification into triglycerides
Reduced hepatic triglyceride synthesis decreases the assembly and secretion of very low-density lipoprotein (VLDL) particles
Lower VLDL secretion reduces circulating triglycerides and the precursor pool for low-density lipoprotein (LDL) formation
Improved lipid metabolism enhances peripheral lipid uptake and reduces ectopic fat deposition without altering high-density lipoprotein (HDL) synthesis
Preservation of lean body mass via mTOR activation prevents the release of free fatty acids from muscle breakdown, reducing substrate for hepatic lipid synthesis
Less supported by current evidence, but not ruled out
Eating more protein triggers gut hormones that signal fullness to the brain and suppress hunger, leading to reduced food intake. This creates a calorie deficit that causes fat loss, which naturally lowers blood fats.
Dietary protein stimulates intestinal L and I cells to secrete glucagon-like peptide-1 (GLP-1) and cholecystokinin (CCK)
GLP-1 and CCK activate vagal afferent nerves and hypothalamic satiety centers, suppressing appetite
High-protein intake suppresses gastric ghrelin secretion, reducing circulating acylated ghrelin levels
Reduced hunger and increased satiety lead to lower daily caloric intake and sustained negative energy balance
Negative energy balance drives adipose tissue lipolysis and reduces circulating free fatty acids, lowering hepatic lipid substrate
Protein requires more energy to digest and convert into body proteins than fats or carbs, so the body burns more calories after eating protein. This higher energy use helps create a calorie deficit that reduces fat stores and improves blood fat levels.
Dietary amino acids undergo deamination and urea synthesis in the liver, consuming ATP and generating heat
Protein synthesis in skeletal muscle and other tissues requires additional energy compared to fat or carbohydrate storage
Increased metabolic activity during protein turnover elevates resting energy expenditure
Higher daily energy expenditure contributes to negative energy balance, promoting fat loss and improved lipid profile
Evidence from Studies
Supporting (1)
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Contradicting (0)
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