When it comes to losing weight, the primary thing that most weight-loss programs focus on is shedding excess body fat. While this can be effective for achieving progress on the scale, it’s ultimately only part of the bigger picture when it comes to improving your appearance.
Body recomposition, on the other hand, is based around the idea that in order to achieve the most positive changes in your appearance, you also have to take into consideration your muscle mass.
While the term body recomposition can technically be used in a couple of different contexts, its most often used to describe a scenario in which fat loss and muscle growth occur simultaneously.
For both of those things to happen though, you have to be doing the right things both in terms of your nutrition and your training. Before we get too deep into the specifics, however, let’s first talk a little more about what body recomposition is and how it works.
What is Body Recomposition?
As opposed to most diets, where simply losing weight is the ultimate goal, body recomposition is an approach that focuses on achieving positive changes in your appearance (and health) through improving your body’s proportion of muscle to fat -- this ratio is known as your body composition.
It’s been well documented that an excessive amount of body fat can increase the chances of experiencing several adverse health outcomes like metabolic syndrome, cardiovascular disease, and cancer. Having a healthy ratio of fat to muscle, on the other hand, has been found to decrease these chances.(1)(2)
While you may lose substantial amounts of body fat with a regular weight loss diet, the issue is that you’ll also typically lose significant amounts of muscle mass, which may make improving your body composition -- and therefore your overall health -- more difficult.
While numerous studies have shown that regular resistance exercise can help to prevent muscle loss during a weight cut, the problem is that even when this happens, many people ultimately don’t end up with the lean, toned look that they’re after -- in many cases, it’s due to the fact that they simply didn’t start off with enough muscle mass -- and that’s where body recomposition comes into the picture.
How Does Body Recomposition Work?
As we’ve already discussed, body recomposition is aimed at reducing your amount of stored fat while simultaneously increasing your muscle mass. In order to do that, however, it takes a basic understanding of the underlying mechanisms behind fat loss and muscle growth.
The Science Behind Fat loss
In order to understand how fat loss works, you have to first understand what body fat is. Body fat is really stored energy that your body taps into when it doesn’t get enough calories from your diet.
A calorie deficit, which is what happens when you take in fewer calories per day than you burn off, therefore forms the basis of any successful fat-loss diet. Although research does show that similar results can be had from both a continuous and alternate day calorie deficit -- i.e. limiting your calories every day versus eating normally some days and limiting them on others.(3)
With that being said, you don’t want your calorie deficit to be too extreme when you’re trying to improve your body composition. The trouble lies in the fact that in order to meet its energy needs, your body tends to breakdown similar amounts of fat and muscle when your calories are severely restricted.
Instead, a modest 10 - 30% energy restriction -- i.e. consuming ten to thirty percent fewer calories than your body burns off each day -- has been shown to better preserve lean body mass, with most studies showing that those on a modest calorie restriction lost less muscle and more fat in comparison to those on a severe restriction.(4)
Cardio and Fat Loss
When it comes to shedding unwanted body fat, nothing is more effective than cardio as far as exercise goes. While you don’t have to do cardio to lose weight, it can have multiple benefits.
On top of helping to improve your heart health, and maximal oxygen uptake, cardiovascular exercise can also increase your body’s energy expenditure, helping to burn up more calories throughout the day. Having a greater calorie-burning potential ultimately makes creating a calorie deficit in your diet that much easier.
The Science Behind Muscle Growth

As opposed to fat loss, muscle growth requires a different approach both in terms of nutrition and exercise. When it comes to building muscle, nothing is more important than protein. Without enough of it in your daily diet, you simply won’t be able to increase the size of your muscles.
Protein -- and more specifically amino acids -- form the structural foundation of all of the muscle tissues throughout your entire body. These proteins are going through a constant state of flux, where physical activity from your day to day life breaks some of them down, requiring your body to repair the damage.(5)
The process through which your body replaces old, broken down proteins with fresh new ones from your diet is known as muscle protein synthesis (MPS) and it is through this general process that your muscles grow.(6) But for that to happen, the amount of muscle protein synthesis that occurs must be greater than the number of muscle proteins that are broken down.
That’s why a high daily protein intake -- 1+ gram of protein per lb of body weight each day -- is absolutely essential when it comes to muscle growth. Without an ample supply of dietary protein, your body simply won’t have the resources it needs to repair damaged muscle tissues, let alone to build them bigger and better.
On top of getting an adequate supply of protein, a calorie surplus is also an important component of the muscle-building process, especially when it comes to individuals with prior weight lifting experience, which we’ll discuss in more detail in the following section. As opposed to a calorie deficit, a calorie surplus occurs when you take in more calories per day than your body burns off.
When it comes to body recomposition, you obviously don’t want to take in so many extra calories that you gain body fat, but you also want to provide your body with enough calories to fuel the muscle-building process. That’s why you only want to have a modest calorie surplus -- somewhere between 250 to 500 extra calories per day -- in order to see the greatest improvements in your body composition.
Weight Training and Muscle Growth
When it comes to building muscle (body recomposition or otherwise), a regular weight lifting routine is absolutely essential. In fact, without the right stimulus, muscle growth won’t occur at all, even when your nutrition is dialed in.
Lifting weight actually causes microscopic damage to your muscle tissues, which your body must, in turn, repair. When it comes to building muscle there is a pretty simple equation: the more damage you cause to your muscle tissues, the more muscle growth that can potentially occur.
In other words, in order to cause the most amount of damage to your muscle tissues -- and therefore, influence the most muscle growth -- you have to be following a challenging weight lifting program.
Your routine should be centrally oriented around compound movements like the bench press, row, squat, and deadlift, which engage multiple muscle groups across multiple joints. Research shows that compared to isolation exercises like the bicep curl, compound exercises damage more muscle tissues, which ultimately equates to more muscle growth over time.
Body Recomposition: A Step By Step Guide
As you can see, fat loss and muscle growth are two unique biological processes, each being achieved through different means -- both in terms of nutrition and exercise.
So then how do you go about combining two seemingly diametrical approaches to nutrition and exercise in a way that facilitates both fat loss and muscle growth at the same time?
Nutrition and Body Recomposition

Well, some research does suggest that in combination with an adequate protein intake and a regular weight lifting routine, you may still be able to increase the size of your muscle on a modest calorie deficit.
For example, one 2010 study compared the effects of a high-protein, hypocaloric diet (DASH diet) alone, to the same diet combined with a regular weight training routine.(7) At the conclusion of the 10-week study, the researchers ultimately found that both groups lost significant amounts of weight.
However, while they did lose substantial amounts of body fat, those on the diet alone also lost an average of 3 pounds in lean mass. On the flipside, subjects who also participated in a weight lifting routine, on average, lost even more body fat in comparison, and actually gained nearly 2 pounds of fat-free mass.
With that being said, it’s important to point out that participants’ muscle gains in the aforementioned study (and others like it) were relatively modest -- remember fat-free mass also includes bone and water.
On top of that, gaining muscle when your calories are restricted appears to become more and more challenging as your training experience goes up.
Most research, involving well-trained athletes, for example, suggests that while a high protein intake and regular resistance training can help to prevent muscle loss during a calorie-restricted diet, those with extensive training backgrounds may find it exceedingly difficult to make gains in muscle mass while dieting.(8)(9)
That’s where the concept of calorie cycling comes into the picture -- it’s an attempt to address some of these basic limitations you may face when trying to combine the muscle-building and fat-loss processes.
Calorie Cycling
The concept of calorie cycling is an approach to body recomposition that modifies your daily calorie intake in accordance with what you’re doing that day. In other words, you’ll be adjusting your calorie intake each day depending on your exercise goals for the day -- how many calories you eat will depend on whether it’s a weight training day, a cardio, or an off day.
Here’s what it looks like:
Weight training days(calorie surplus) - calories in should be greater than calories out | ||
Cardio days(maintenance) - calories in and calories out should be equal | ||
Non-training days(calorie deficit) - calories in should be less than calories out |
In order to be able to accurately adjust your calories from day to day, you must first know your total daily energy expenditure (TDEE), which represents the total number of calories you burn off in a day at your current weight. You can easily estimate your TDEE using an online calculator (make sure to set your activity level to “little or no exercise”/sedentary).
Once you know your TDEE, you have your maintenance calorie target, which is what you will be shooting for on days in which you do cardio. So for example, if you know that it takes you 2,000 calories to maintain your current weight, that is what you would eat on cardio days.
Because you’ll be doing cardio, you’ll be expending more energy than normal, which will actually put you in a slight deficit even though you’re technically consuming your “maintenance calories”. This, in turn, can help to maximize your fat-burning potential and prevent the loss of lean muscle mass on cardio days.
Your weight training days are the days you’re really going to be focused on fueling the muscle-building process and that means consuming a calorie surplus. However, you don’t want to consume too many excess calories on lifting days.
Instead, you want to provide your body with enough extra energy for muscle growth to occur without taking in so many extra calories that some are ultimately converted into body fat. When it comes to body recomposition, that means going with a modest calorie surplus of between 250 - 500 calories over your TDEE on days in which you are weight training.
On days in which you don’t exercise at all, weight loss is the primary goal. You’ll be applying somewhere around a 10% restriction to your daily calorie intake. Maintaining a relatively modest calorie deficit on your off days will help you to more exclusively burn fat and spare lean muscle mass as your body turns to itself to meet its energy needs.
The Role of Protein
No matter if it’s a training day or not, in order to build lean muscle while you’re shedding body fat, you absolutely have to be consuming an ample amount of protein. Numerous studies have found that compared to a low protein diet, a diet high in protein leads to significantly greater increases in fat-free muscle mass when combined with a resistance training program.(10)
Long story short, in order to maximize your muscle-building potential during your body recomposition, you need to be consuming 1+ grams of protein per pound of body weight each day -- that means on cardio days and off days as well, not just weight training days.
So for example, if you weigh 195 pounds, your daily target would be to consume at least 195 grams of protein. Although you do want to make sure that you’re not going too far overboard with your protein intake. According to the NIH, no more than 35% of your total daily calories should come from protein-based food sources.
Exercise and Body Recomposition

On top of your nutrition, in order to have a successful body recomposition, you also have to be doing the right things when it comes to exercising.
Weight training
As far as weight lifting goes, in order to see muscle growth, you need to be putting enough time in at the gym. That means 3+ sessions per week of moderate to heavy resistance training (i.e. working with weights that you can lift for between 6 -12 reps) with a focus on compound movements that collectively engage all of the major muscle groups.
In general, those with extensive training backgrounds will ultimately require more sessions per week than those with little to no prior experience.
On top of putting enough time in at the gym, in order to maximize your muscle-building potential, you also have to be focused on making gradual but regular improvements on the different exercises in your weight lifting program -- if your strength is going up, it’s a good indication that you’re gaining muscle mass
On the other hand, if you're not seeing modest increases in things like the amount of weight you’re able to lift and/or the number of sets/reps you’re able to do, it’s a sign that you need to adjust your program.
Cardio
When it comes to weight loss cardio can be an effective tool, but you don’t want to overdo it. As little as 2 cardio sessions per week (on different days than your weight training) can be an effective way to burn up some extra calories without interfering with your progress in the weight room.
The issue is that doing too much cardio can actually impinge on the ability of your muscles to react and adapt to resistance training, which in turn, can blunt the muscle-building process.
Before you get too worried that you won’t lose fat if you don’t do enough cardio, it’s important to point out that the only factor that’s absolutely essential for fat loss is a calorie deficit. As long as you have a calorie deficit, you will shed body fat, no matter how much or how little cardio you do.
With that being said, regularly including cardio in your weekly workout routine can be an effective way to increase your total daily energy expenditure, which can ultimately help you to shed more body fat.
While most people tend to turn to steady-state cardio -- i.e. longer-duration, lower-intensity exercises like jogging on a treadmill -- research shows that high-intensity interval training (HIIT) may be even more effective when it comes to shedding body fat.
HIIT entails short-duration, high-intensity exercises like sprints and research shows that while both HIIT and steady-state cardio can result in significant amounts of weight loss, HIIT helps to preserve more lean muscle mass, helping to more exclusively target body fat and improve your body composition to a greater degree than with steady-state.(11)
Supplementation and Body Recomposition

When it comes to body recomposition, nothing is more important than diet and exercise, however, supplementation can also aid in the process. Taking the right kinds of dietary supplements can not only increase your ability to build muscle, but it can also improve your fat-burning potential.
Muscle-Building Supplements
Several natural dietary supplements have been shown to increase your levels of muscle protein synthesis, which again, is the process through which your body actually builds new muscle tissues. Keeping these levels elevated through supplementation ultimately helps to put your body in the ideal position for muscle growth to occur.
⫸Whey Protein
When it comes to maximizing your muscle-building potential, nothing is more effective than whey protein. Whey is a fast-digesting protein which makes it the perfect post-workout snack and research shows that it produces greater spikes in muscle protein synthesis than any other type of protein.(12)
On top of helping to increase your levels of MPS, whey protein is also incredibly handy for hitting your daily protein target. While maintaining a high daily protein intake can be daunting, adding a couple of protein shakes into your daily diet can be an easy way to make achieving your goal more realistic. Most high-quality whey protein powders contain 25+ grams of protein per serving, so if you have 2 shakes a day, that’s 50+ grams of protein out of the way.
⫸HICA & HMB
HICA and HMB are natural amino acid metabolites that through different pathways, can also help to boost your levels of MPS. Several randomized controlled trials have demonstrated that compared to diet and exercise alone, those who also supplemented with HICA and HMB, on average, saw significantly greater gains in lean muscle mass.(13)(14)
Other research has also demonstrated that HMB may also help to prevent muscle protein breakdown, which in turn, can create a more positive protein balance, helping to improve your muscle-building potential even further.(15)
⫸Phosphatidic acid
Phosphatidic acid is a natural signaling lipid that has been shown to activate the mTOR signaling pathway, which is responsible for coordinating the delivery of proteins, oxygen, and other important biochemical to muscle cells in need of repair.(16)
Research shows that regular phosphatidic acid supplementation leads to significant increases in MPS, which in turn has been shown to lead to greater gains in lean muscle mass compared to diet and exercise alone.(17)(18)
Fat-Burning Supplements
⫸Conjugated Linoleic Acid (CLA)
Conjugated Linoleic Acid (CLA) is a naturally occurring substance that’s actually the combination of over 20 different linoleic acid isomers. While research involving human subjects is still somewhat limited, there is some evidence that CLA may help to increase lipolysis, which is the technical term for the process through with the body breaks down adipose tissue (aka fat stores).(19)
For example, one meta-analysis involving 18 different randomized controlled trials ultimately found a small but significant association between CLA and fat loss, with those who were regularly given a CLA supplement losing substantially more body fat on average in comparison to individuals who were only received a placebo.(20)

⫸Alpha GPC choline
Alpha GPC choline is a natural precursor to acetylcholine, a multipurpose neurotransmitter that performs a number of different roles in the body. Amongst other things, some research suggests that acetylcholine may play an important role in fatty acid oxidation, helping to convert more stored fat into usable energy.(21)(22)
For instance, one short-term 2014 study ultimately found that compared to those following a calorie-restricted diet and regular exercise program alone, those who also took a daily choline supplement in addition to diet and exercise, on average, lost significantly more weight.(23) Not only did participants lose more weight, but they also saw a significantly greater reduction in body fat percentage and BMI over the course of the trial.
Wrap Up
While it can have multiple connotations, the term body recomposition most often refers to the process of shedding body fat and build muscle simultaneously. While fat loss and muscle growth require different approaches both in terms of nutrition and exercise, there is a way to combine the two.
While those who no previous training experience may be able to build some muscle on a continuous calorie restriction, the most effective approach to body recomposition may be calorie cycling.
With calorie cycling, you’ll be switching up your calorie intake depending on your training goals for the day. On weight lifting days, you’ll be consuming a slight calorie surplus ( +250 - 500 extra calories). On cardio days, you’ll be consuming your maintenance calories and on off-days, you’ll be moderately reducing your calorie intake ( 10% restriction).
On top of managing your calorie intake, having a high protein intake is also important when it comes to body recomposition. In order to see substantial amounts of muscle growth, you need to be consuming 1+ grams of protein per pound of bodyweight every day.
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- “Effects of High Versus Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes Engaging in an 8-Week Resistance Training Program”Campbell, B.I., Aguliar, D., Conlin, L., Vargas, A., Schoenfeld, B.J., Corson, A., Gai, C., Best, S., Galvan, E., Couvillion, K. Homan Kinetics Journal. 2018.
- “The Impact of Different High-Intensity Interval Training Protocols on Body Composition and Physical Fitness in Healthy Young Adult Females”Brown, E.C., Hew-Butler, T., Marks, C.R.C., Butcher, S.J., Choi, M.D. Mary Ann Liebert. Nov. 2018.
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- “The effects of 12 weeks of beta-hydroxy-beta-methylbutyrate free acid supplementation on muscle mass, strength, and power in resistance-trained individuals: a randomized, double-blind, placebo-controlled study”Wilson, J.M., Lowrey, R.P., Joy, J.M., Anderson, J.C., Wilson, S.M.C., Stout, J.R., Duncan, N., Fuller, J.C., Baier, S.M., Naimo, M.A., Rathmacher, J. European Journal of Applied Physiology. Mar. 2014.
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