A cutting phase is a dietary strategy involving a caloric deficit, aiming to maximize fat loss while preserving existing muscle mass. Protein and fat intake are typically fixed at minimum levels to support muscle and hormonal health. Once these two macronutrients are established, carbohydrate intake becomes the most flexible variable, adjusted to fit the remaining calorie budget.
The Role of Carbohydrates During a Cut
Carbohydrates are the body’s preferred fuel source, especially for the high-intensity training needed to signal muscle retention during a calorie deficit. They are stored in the muscles and liver as glycogen, which powers resistance exercise sessions. Maintaining these glycogen stores allows for continued heavy lifting, preventing the loss of strength and intensity that occurs on a severely restricted diet.
Carbohydrates also play a role in muscle preservation through their protein-sparing effect. When carbohydrate availability is low, the body may convert amino acids from muscle tissue into glucose for energy (gluconeogenesis). Consuming sufficient carbohydrates helps prevent this, ensuring that dietary protein is used for muscle repair rather than being burned as fuel.
Determining the Baseline Carb Target
The most practical method for calculating a baseline carbohydrate target is to first establish the intake for protein and fat, then allocate the remaining calories to carbohydrates. Protein should be set high, typically between 0.8 and 1.2 grams per pound of body weight, or 1.0 to 1.4 grams per pound of lean body mass, to support muscle tissue. Fat intake is generally kept at 20 to 30 percent of total daily calories to support hormone production and health.
Once the total calories from protein and fat are subtracted from the daily calorie target, the residual amount is dedicated to carbohydrates, using the conversion of four calories per gram. For instance, if 700 calories remain, this equates to 175 grams of carbohydrates per day. This “calories remaining” method ensures the total daily calorie goal is met, making it the most precise approach for a cutting phase.
An alternative method is using a fixed multiplier based on body weight, typically 1.0 to 2.0 grams of carbohydrates per pound of body weight. This range offers a straightforward calculation that can be adjusted based on training volume and individual response. For those who prefer a percentage-based approach, setting carbohydrates at 30 to 40 percent of total daily energy expenditure is common for fat loss. This percentage allows for adequate fueling while accommodating the high-protein and moderate-fat requirements of a cutting diet.
Adjusting Carb Intake for Training and Rest Days
Once a baseline intake is established, the total weekly carbohydrate allotment can be manipulated using carb cycling. This involves alternating between higher-carbohydrate days and lower-carbohydrate days to optimize performance and fat loss. High-carb days coincide with heavy or intense training sessions, providing maximum energy for performance and promoting muscle glycogen replenishment.
On training days, carbohydrate intake is increased above the baseline target, often drawing from the total weekly pool of calories. Conversely, on rest days or days with low-intensity activity, carbohydrate intake is lowered. This reduction in glucose availability encourages the body to switch to fat oxidation as its primary fuel source, supporting the goal of fat reduction.
A short-term high-carb adjustment, often called a refeed day, can be incorporated once or twice a month during longer cutting phases. A refeed involves a temporary spike in carbohydrate intake, increasing total calories for a single day to maintenance or slightly above. This higher carbohydrate intake may offer a psychological break from the deficit and help regulate appetite-controlling hormones like leptin, which can drop during prolonged dieting.
Selecting Carbohydrate Sources
When calories are restricted during a cut, the quality of carbohydrate sources becomes significant, focusing on nutrient density and satiety. Complex, high-fiber sources are digested slowly and provide a sustained release of energy. Prioritizing foods like whole grains, legumes, vegetables, and whole fruits helps manage hunger, a common challenge in a calorie deficit.
The fiber content in these sources adds volume to meals without adding many calories, contributing to a feeling of fullness. Examples include brown rice, quinoa, oats, sweet potatoes, and various beans and lentils. These whole-food options also deliver vitamins and minerals necessary for metabolic function.
Simple sugars and highly processed carbohydrates, such as white bread, sugary drinks, and baked goods, should be limited. These refined sources lack the fiber and micronutrients of whole foods and are quickly digested, leading to energy spikes and subsequent crashes. Selecting slow-digesting, high-fiber carbohydrates keeps the cutting diet manageable, providing consistent energy for training.