Nutrition during cutting: the basic principles
Cutting is not a set of “forbidden” foods but a controlled energy deficit, during which the main task is to lose fat and preserve muscle. The editorial team gathered the principles with the best evidence base that work regardless of a fashionable diet.
What cutting is from the standpoint of physiology
In the sports world, “cutting” refers to the period when the goal is to reduce the percentage of body fat while preserving as much muscle mass and strength as possible. From a scientific point of view this is simply a controlled energy deficit combined with strength training and sufficient protein. Physiology requires no “special cutting foods.”
When the body receives less energy than it expends, it covers the difference from its reserves — mostly fat, but partly from muscle protein as well. The task of properly built nutrition is to shift this ratio in favor of fat. There are three levers for this: the size of the deficit, the amount of protein and the training stimulus.
The ISSN position on diets and body composition (Aragon et al., 2017) emphasizes that with equal calories and protein, different schemes — low-carbohydrate, low-fat, with intermittent fasting — produce similar results for fat loss. What is decisive is maintaining the deficit, not the “magic” of a specific diet.
That is why in this article the editorial team focuses on the basic principles that work regardless of the chosen eating style: how to determine the deficit, how much protein is needed, how to distribute carbohydrates and fats and how to assess progress.
The size of the deficit and the rate of weight loss
The most common mistake is too large a deficit at the start. The desire to see definition quickly leads to a sharp cut in calories, which in the short term gives a fast minus on the scale (mostly water and glycogen) and in the long term — loss of muscle, a drop in strength and a breakdown of the diet.
A study by Garthe and colleagues (2011) on elite athletes compared two rates: roughly 0.7% and 1.4% of body weight per week. The group with the slower rate on average preserved, and in some cases even gained, lean mass and strength. The review by Helms and colleagues (2014) for natural bodybuilders recommends aiming at 0.5–1% of body weight per week.
In practice the calculation starts with an estimate of maintenance calories (from a food diary and stable weight over 2–3 weeks or from formulas) and subtracts 15–25%. Then the figure is adjusted for the actual rate: if the weight does not move for two weeks in a row with accurate tracking, the deficit is increased by a small step.
The lower the body-fat percentage becomes, the slower the rate should be. A lean athlete approaching competition shape risks losing much more muscle than a person with excess weight, so at the final stages 0.5% per week is an entirely adequate benchmark.
Protein — the main protector of muscle
In an energy deficit the need for protein increases. A systematic review by Helms, Zinn and colleagues (2014), devoted to trained lean athletes in a deficit, concluded that consuming roughly 2.3–3.1 g of protein per kilogram of lean body mass is advisable. For a person with a moderate body-fat percentage this usually corresponds to about 1.8–2.7 g per kilogram of total mass.
A randomized study by Longland and colleagues (2016) showed that young men in a pronounced deficit with intense training who received 2.4 g/kg of protein gained more lean mass and lost more fat than a group on 1.2 g/kg. This is one of the most striking pieces of evidence for the role of protein specifically during cutting.
Protein is also the most satiating macronutrient and has the highest thermic effect — more energy is spent on digesting it than on carbohydrates or fats. For a person who feels constant hunger on a diet, this is an important practical bonus.
It is worth distributing protein across 3–5 meals of 0.4–0.5 g/kg, including a meal after training and, if desired, before sleep. The sources are lean meat, fish, eggs, dairy, legumes; protein powder is convenient for filling “gaps” in the plan but is not mandatory.
Carbohydrates, fats and fiber
After calories and protein have been determined, the rest of the energy is distributed between carbohydrates and fats. Helms and colleagues (2014) advised keeping fats at roughly 15–30% of calories so as not to disrupt hormonal function, and giving the rest to carbohydrates, which ensure the quality of training.
| Component | Baseline benchmark during cutting | Why |
|---|---|---|
| Calories | A deficit that gives 0.5–1% of body weight per week | Fat loss without excessive muscle loss |
| Protein | ≈2.3–3.1 g/kg of lean mass | Preserving muscle, satiety |
| Fats | ≈15–30% of calories | Hormonal function, fat-soluble vitamins |
| Carbohydrates | The remaining calories, closer to training | Training intensity, glycogen replenishment |
| Fiber | Vegetables at every meal | Satiety, bowel function |
A complete rejection of carbohydrates is not mandatory. For a strength athlete they are important as fuel for training, and a sharp cut in them often reduces training volume — and it is precisely the training stimulus that signals the body to “preserve muscle.” A convenient strategy is to concentrate carbohydrates around training.
Vegetables, berries, legumes and whole grains provide a large volume of food with relatively few calories. This helps to tolerate the deficit psychologically. High-calorie liquids — juices, sweet drinks, alcohol — on the contrary, are the easiest way to imperceptibly “eat up” the entire deficit.
As for micronutrients: the lower the calories, the harder it is to meet the need for vitamins and minerals from food alone. A variety of foods and, if needed, a basic multivitamin complex help to avoid deficiencies.
Tracking progress and common mistakes
The scale is an important but not the only tool. Daily fluctuations in weight due to water, salt and bowel contents can reach 1–2 kg, so it is worth weighing yourself every day under the same conditions and looking at the weekly average. In addition — waist measurements and a photo once a week, as well as the dynamics of working weights in the gym.
- too large a deficit at the start and sharp “cuts” at every stall in weight;
- insufficient protein and cutting strength training in favor of cardio;
- not accounting for “hidden” calories — oils, sauces, drinks, snacks;
- chronic lack of sleep, which increases hunger and worsens recovery;
- the absence of a plan for exiting the diet.
Sleep deserves a separate mention. Studies show that sleep deprivation against the background of a calorie deficit shifts weight loss toward lean tissue and increases appetite. Seven or more hours of sleep is just as much a cutting tool as calculating macronutrients.
A prolonged deficit is accompanied by metabolic adaptation: energy expenditure drops more than can be explained by the loss of weight. That is why on long cuts planned breaks or “maintenance days” are often used, and at the end of the diet — a gradual return to maintenance calories.
Psychological health is also important. If the diet is accompanied by obsessive thoughts about food, episodes of overeating or a fear of certain foods, this is a reason to stop and turn to a specialist.
Editorial conclusions
The basic principles of cutting are simple: a moderate calorie deficit, high protein, strength training, enough carbohydrates for quality training and no less than 15–20% of calories from fats. A specific diet is only a way to implement these principles.
A slow rate of 0.5–1% of body weight per week preserves muscle better than an aggressive one. Progress is assessed by the average weight, measurements and strength, not by a single weigh-in.
Sleep, control of “hidden” calories and a plan for exiting the diet determine the long-term result no less than the deficit itself.
We recommend continuing your reading with our materials on metabolic adaptation during dieting, the reverse diet after cutting and the cheat meal.
References
- Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr. 2014;11:20.
- Helms ER, Zinn C, Rowlands DS, Brown SR. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes. Int J Sport Nutr Exerc Metab. 2014;24(2):127–138.
- Longland TM, Oikawa SY, Mitchell CJ, Devries MC, Phillips SM. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial. Am J Clin Nutr. 2016;103(3):738–746.
- Garthe I, Raastad T, Refsnes PE, Koivisto A, Sundgot-Borgen J. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. Int J Sport Nutr Exerc Metab. 2011;21(2):97–104.
- Aragon AA, Schoenfeld BJ, Wildman R, et al. International Society of Sports Nutrition position stand: diets and body composition. J Int Soc Sports Nutr. 2017;14:16.
- Roberts BM, Helms ER, Trexler ET, Fitschen PJ. Nutritional recommendations for physique athletes. J Hum Kinet. 2020;71:79–108.
Andriy Melnyk
A strength-sports coach and author of programs for beginner and intermediate levels. Writes about training planning.
