Body recomposition diet — what to eat

A body recomposition diet balances sufficient protein intake, the right amount of calories, and nutrient timing to support muscle maintenance or growth while promoting fat loss. This article explains the practical dietary choices that best support recomposition.

This article is from the Nutrition section of our Library.

This article is part of a four-part series on body recomposition — the process of losing fat while maintaining or building muscle. Across the series, we cover what recomposition is and how it comes about, the role of resistance training, nutrition, and rest. Each article builds on the previous one to provide a complete overview, so please read away!

Articles in this series:

Article 1: What Is Body Recomposition?
Article 2: Training for Body Recomposition
Article 3: Nutrition for Body Recomposition
Article 4: Rest and Recovery for Body Recomposition

For body recomposition, good nutrition is crucial because you're asking your body to simultaneously support two processes (fat loss and muscle maintenance or growth) that have traditionally been viewed as incompatible.

How much protein do you need to eat for body recomposition?

Your muscle tissue isn't static. At every moment, muscle proteins are being broken down and rebuilt in a continuous cycle called protein turnover.

After resistance training, the process of muscle growth is elevated for up to 48 hours. However, when you’re in an energy deficit, it can potentially impair the growth stimulus.

This is where protein intake becomes important, as it can help counteract the growth-suppressing effects of having less energy available.

First and most obviously, protein supplies the amino acids that serve as the building blocks of muscle. Your body cannot make muscle proteins without several amino acids (called “essential” amino acids), which can only come from your diet.

Without adequate dietary protein, even the strongest training stimulus cannot produce meaningful muscle growth because the raw materials simply aren't there.

Second, protein has a unique capacity to stimulate muscle growth directly. Certain amino acids, particularly leucine, activate the signalling pathways that stimulate muscle growth processes. This means protein intake doesn't just provide materials; it also triggers the construction process itself.

Third, during an energy deficit, protein becomes increasingly important for preserving muscle.

Research consistently shows that higher protein intakes (1.6–2.4 g/kg body mass) during caloric restriction result in greater preservation of fat-free mass compared to lower protein intakes, even when total weight loss is similar — a clear demonstration of better body recomposition.

Fourth, protein has the highest thermic effect of all the macronutrients, meaning your body expends more energy digesting and processing protein compared to carbohydrates or fats.

This modest but meaningful increase in energy expenditure can support fat loss goals. It has a lower “metabolisable” energy density than fat or carbohydrate, and it is more satiating — meaning it will help reduce hunger more effectively.

How many calories should you eat for body recomposition?

Calories aren't a target to hit with precision; they're a boundary condition that determines what's physiologically feasible. Being in an energy deficit means your body must source energy from stored reserves, primarily fat but potentially also protein from your muscles.

The question is, how large a deficit can you sustain whilst still supporting muscle growth?

While you can run a deficit and grow muscle, those exceeding 500 kcal a day deficit tend to impair your ability to preserve or grow muscle.

Very large deficits (meeting less than half your energy needs) will likely turn on muscle breakdown processes, which not even very high protein and regular resistance training can offset.

In fact, the dietary protein that you consume will end up being used for energy, rather than building muscle. And the net effect is that you’ll end up losing muscle over time.

A moderate 300 to 500 kcal a day deficit seems like a sensible target. Smaller deficits will favour muscle growth but slow fat loss, whereas larger deficits will do the opposite. There is not really a standard, one-size-fits-all recommendation.

A Double Effect

Good news. Your stored fat can, to a degree, support the energy costs of building new muscle. Yes, your muscles can use your own fat stores for energy.

When you’re in an energy deficit, your body breaks down stored fat to use for energy. If you're eating enough protein, resistance training, and the energy is not required elsewhere, for more important things, it can be used to build muscle.

This is one of the reasons why those with more fat have greater potential for body recomposition and can potentially run larger energy deficits, as they can tap into their own fuel reserves in their fat tissue.

As your body becomes leaner, body recomposition becomes increasingly more difficult.

Other Nutrients

Whilst protein and total energy are the most influential, there are a few other considerations.

Carbohydrate intake, while not as critical as protein, can support training performance and recovery in between bouts of exercise.

Dietary fat is also often overlooked. Inadequate amounts of dietary fat can impair testosterone production, which in turn could impair muscle maintenance or growth.

However, once the minimum requirements of fat (e.g., 0.5-0.8 g/kg body mass) and protein are met, the remaining calories from fat and carbohydrate can be adjusted to your personal preferences and training demands.

Deficiencies in some micronutrients like vitamin D, zinc and magnesium can potentially impair body recomposition prospects. However, these are generally “threshold effects”, meaning correcting deficiencies matters, but super-dosing won’t improve muscle growth or fat loss.

A Strategic Foundation

Nutrition for body recomposition isn't about following a perfect meal plan or hitting precise macro targets to the gram.

It's about understanding the biological principles and creating a sustainable approach that provides adequate protein, maintains a moderate energy deficit, and supports training performance.

Research consistently shows that higher protein intakes (over 1.6 g/kg body mass) combined with moderate energy deficits (~ 500 kcal) and resistance training create an optimal environment for body recomposition.

In the final article of this series, we'll look at the last piece of the puzzle: rest. This includes recovery, sleep and stress. We’ll also round up all the principles and discuss the practical application of them.

3 Quick Questions

Q: If I'm eating enough protein, can I eat very few calories and still build muscle?

No. Whilst adequate protein is essential, very large energy deficits (typically more than 500 kcal below maintenance) create an environment that will impair muscle growth, and possibly lead to muscle wasting.

Q: Does the timing of protein intake matter for body recomposition?

Timing appears to matter, but less than your total daily intake. Ensuring you consume enough protein on your training days and the day after is particularly important.

It is probably easier to hit your protein targets if you spread your protein intake throughout the day (rather than eating it all at once).

Q: I've been doing body recomposition for months, and progress has slowed dramatically. What's happening?

This is normal. Body recomposition becomes progressively more difficult as you become leaner and more trained. If you've lost substantial fat and gained noticeable muscle, you may have reached a point where further recomposition becomes more difficult.

At this stage, it may be more efficient to have dedicated phases of either building muscle (“bulk”) or losing fat (“cut”) than to do both at the same time.