Alpha Progression
Low-carb diet
Also known as: Low-carbohydrate diet
A low-carb diet reduces carbohydrate intake relative to a person's usual diet or a comparison diet. Research definitions vary, but a common threshold is below about 130 grams per day or below 26% of total energy. Low carb does not automatically mean ketogenic, high protein, or low calorie.
Carbohydrate can be replaced by fat, protein, or both, so two low-carb diets may have very different foods and health effects. Vegetables, nuts, seeds, dairy, berries, and limited legumes or whole grains can still fit some versions. The amount and quality of fiber, unsaturated and saturated fat, protein sources, and overall dietary variety remain relevant; carbohydrate grams alone do not measure diet quality.
For fat loss, low carb works when it produces a sustainable calorie deficit. A Cochrane review of 61 randomized trials found probably little to no difference in weight reduction or several cardiovascular risk markers between low-carbohydrate and balanced-carbohydrate weight-loss diets for up to two years. Individual appetite, food preferences, and adherence can still make one approach easier than another.
In strength training, reducing carbohydrate may lower glycogen and perceived training energy, but the effect depends on prior intake and session demands. A systematic review of resistance exercise found little reason to expect extra carbohydrate to improve fed sessions of modest volume, while higher-volume or fasted training was more likely to benefit. Low carb is therefore not automatically incompatible with lifting, nor is it proven superior for strength or muscle growth.
Very low intake can cause headaches, constipation, fatigue, or rapid early water loss, and diabetes or blood-pressure medication may require clinical adjustment as intake and body weight change. Anyone using glucose-lowering medication, pregnant, managing kidney or other medical disease, or showing signs of an eating disorder should seek individualized guidance rather than making a severe restriction alone.
