Nutrition

A caloric surplus is when you consume more calories than your body burns in a day, causing your body to store the excess energy and gain weight.

A caloric deficit is when you consume fewer calories than your body burns in a day, forcing your body to use stored energy and causing fat loss.

Maintenance calories are the number of calories you can eat each day to keep your body weight stable — neither gaining nor losing.

TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns in a day, combining your resting metabolism with the energy used for activity, exercise, and digestion.

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to keep you alive — powering your organs, breathing, and cell function.

Macronutrients are the three nutrients your body needs in large amounts and that supply calories: protein, carbohydrates, and fat.

Protein is the macronutrient that builds and repairs muscle and other tissues, made up of amino acids and providing 4 calories per gram.

Carbohydrates are the body's main energy source, broken down into glucose to fuel training and daily activity, providing 4 calories per gram.

Dietary fat is an essential macronutrient needed for hormone production, vitamin absorption, and cell health, providing 9 calories per gram.

Fiber is a type of carbohydrate the body can't digest, which supports gut health, digestion, and satiety while adding few or no calories.

Micronutrients are the vitamins and minerals your body needs in small amounts to function properly, support health, and enable performance.

The glycemic index (GI) is a ranking of how quickly a carbohydrate-containing food raises blood sugar, from low (slow) to high (fast).

Protein timing is the practice of distributing protein intake around training and across the day to support muscle growth and recovery.

Meal timing refers to when you eat across the day and around training, and how that affects performance, recovery, and body composition.

Intermittent fasting (IF) is an eating pattern that cycles between periods of eating and fasting, such as the popular 16:8 method.

Reverse dieting is the practice of gradually increasing calories after a diet, aiming to return to maintenance while limiting fat regain.

Hydration is maintaining adequate fluid in the body for performance, recovery, temperature control, and overall health.

Muscle protein synthesis (MPS) is the process by which the body builds new muscle protein, stimulated mainly by resistance training and protein intake.

Leucine is an essential amino acid that acts as the primary trigger for muscle protein synthesis, making it especially important for building muscle.

Essential amino acids (EAAs) are the nine amino acids the body cannot produce itself and must obtain from food, required for building protein and muscle.

Protein quality describes how well a protein source supplies essential amino acids and how easily the body digests and uses it.

The thermic effect of food (TEF) is the energy your body uses to digest, absorb, and process the food you eat, accounting for around 10% of daily calorie burn.

Satiety is the feeling of fullness and satisfaction after eating that reduces the desire to eat more, a key factor in controlling calorie intake.

Flexible dieting (also called IIFYM, 'If It Fits Your Macros') is an approach where you hit daily protein, carb, and fat targets without banning specific foods.

Carb cycling is varying your carbohydrate intake across days — typically higher on training days and lower on rest days — to match energy needs.

A diet break is a planned period of eating at maintenance calories during a longer diet, used to ease the physical and mental strain of a deficit.

Electrolytes are minerals — including sodium, potassium, and magnesium — that carry an electrical charge and regulate hydration, nerve signals, and muscle function.

Omega-3 fatty acids are essential fats — found in fatty fish and some plants — linked to heart health, brain function, and reduced inflammation.

Added sugar is sugar put into foods and drinks during processing, as opposed to the sugar naturally present in whole foods like fruit and milk.

Alcohol and fitness describes how drinking affects training, recovery, muscle building, and fat loss — largely through calories, sleep, and recovery.