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Nutrition for gaining muscle without fat

Gain muscle mass fast

Fork with measuring tape wrapped around it like pasta


7. Learnings

The gist

  1. A research study that tested the effects of adding 500 calories to the diets of those on a resistance training program found that the extra calories added fat, not muscle.

  2. To gain muscle you need enough protein and enough calories. Excess calories to the point of fat gain will not speed up this process and neither will excess protein.

  3. To maximize rates of muscle growth, you want to find the high end of your metabolic range.

  4. Follow the provided step-by-step process which includes watching your weight, body composition and/or strength, and continually adding small amounts to your daily intake to find this point.

  5. Those described as “hard-gainers” (e.g. those in their early 20’s, teens, and those with active jobs) will have a much larger metabolic range than others.

You gotta eat BIG for BIG gains... right?

You want to build more muscle and may have heard that the fastest way to do this is to “bulk” by eating BIG. Do you really need that additional body fat from bulking in order to gain muscle quickly? Is it necessary to eat all those extra calories?

Let’s check out this research study by Garthe and colleagues at The Norwegian School of Sports Science in Oslo, Norway [1]:

The study divided participants into two exercise groups:

  1. Resistance training and adding 500 extra calories on top of a maintenance diet

  2. Resistance training and no addition to diet

The results: Gains in lean body mass did not vary between groups. However, fat mass increased more in the +500 calories group.

In other words, they concluded that all the extra calories added was extra fat.


Here is a table from the study:

You can see that there is no statistical difference in LBM (Lean Body Mass) in the NCG (+500 calories) group, but a massive gain in fat mass.

What if there was a way to get that extra bit of increased rate of muscle gain without the added fat?

The 2 critical nutrition components for gaining muscle


Protein synthesis or, in other words, muscle growth is dependent on dietary protein and resistance training.

The key is enough to maximize rates of muscle growth. Remember, your body can only use so much protein (i.e. 0.3 g/kg) and can only add so much muscle at one time (i.e. every 3-5 hours). Therefore, more protein after this point does not equal more gains.

For more on this see our resource Protein for gaining muscle: there’s more to it than just hitting a daily target


Your body’s gas tank. Energy must be provided to fuel workouts, the protein synthesis process and to actually be incorporated into muscle tissue (i.e. the protein calories).

You want to be at the high end of your metabolic range while maintaining body fat levels so energy is easily available for both muscle growth and high performance in the gym.

What is your metabolic range? And where should you be in this range?

All of us have a range of calories where we can maintain body fat levels and some people's range is much larger than others [5].

For example, Suzy Q. does not gain weight if she eats over 1743.42 calories per day or lose weight if she eats under it. This is because a person’s calories for weight maintenance are not at a set point that is this refined. Instead, it is more likely that if she eats within a certain range (e.g. 1600-1900) she will not gain or lose fat.

For muscle gain without fat gain, what we are looking for is the high end of your range.

In Suzy’s case, she should be aiming for closer to 1900 calories to maximize the amount of energy her body has for great workout performance and building muscle without gaining fat. This is where the additional burn between 1600 and 1900 will go: increased muscle generation, increased workout performance, increased subconscious activity away from the gym and, for some, possibly a small increase resting metabolic rate.

We can use the analogy of your body as a race car: If the driver has the premiums and extra cash they are going to be less conservative on the gas pedal and will also spend more on the upgrades under the hood. So if your body has the extra energy, it can afford to expend more fuel on movement, performance, and on upgrading its muscles!

Therefore, you may need to increase your intake but only to the point where you are not gaining significant amounts of fat. You can figure this out by continually and slowly increasing the number of calories you consume while watching the important metrics discussed below.

Finding your metabolic range

If you want more tangible numbers, Eric Helms, natural bodybuilding coach for 3DMJ, PhD in Exercise Physiology, and professor at Auckland University, estimates:

  • Beginners can expect to gain 1 to 1.5% body weight per month

  • Intermediates, 0.5 to 1% per month

  • And advanced, 0.5% or less per month



  1. For a 180 lb male that’s 2-3 lbs/month for the first 4-8 months and less than 1 lbs per month after 3 to 5 years of consistent training.

  2. For a 130 lbs female it would be 1-2 lbs/month as a beginner and less than 0.7 lbs per month as an advanced lifter.


To maximize gains, avoid the deficit and avoid going overboard

Being in an energy deficit (weight loss) drastically blunts the rates at which muscle growth can occur [2]. Knowing there isn’t as many calories available, your body doesn’t want to spend much on the energy expensive process of building muscle.

However, being in a caloric surplus beyond the increase needed to fuel the muscle building process and high performance has no effect on increasing rates. Therefore, more calories after this point does not equal more gains, except in fat.

Can you lose fat AND build muscle?

While fat can be very easily stored at almost no metabolic cost, this is not true for muscle mass. Muscle mass is much more metabolically costly to synthesize than body fat. In other words, it’s a lot more work for your body to build and maintain muscle than fat.

Overweight individuals can lose more body fat and keep more muscle because there is more fat to mobilize [3]. For those new to resistance training, muscle growth occurs much more quickly so the effect of gaining muscle while losing fat will be more pronounced [4].

Therefore, the more overweight the person is and the less experience they have resistance training (i.e. further they are away from their genetic potential for muscle mass), the more capable they will be of gaining muscle and losing fat at the same time. Keep this in mind if this is your situation. The weight on the scale may not move, but look for improvements in the gym, the mirror and the way your clothes fit!

I’m a “hard-gainer”, why am I not gaining muscle?

Individuals, commonly those in their early 20’s and teens, could find themselves adding and adding and adding calories with no gains in muscle, strength or weight. If you’re one of these individuals, you may indeed find yourself eating BIG.

The process of building muscle increases caloric expenditure and this along with increases in NEAT (subconscious everyday physical activity away from the gym, such as walking and fidgeting) contributes to this “hard-gainer” phenomenon. Essentially, you eat more and your body will find more ways to use this energy. This is the main reason why weight gain is much less than expected after a caloric increase [5,6].

This may also be the case for those who have active jobs. You would be surprised by how many extra calories your body will burn in your daily activities if it has them available.



In comparison with Suzy Q.’s metabolic range of 1600-1900, hard-gainer Katy Doe’s range is 1800-2300. Where Suzy should be aiming closer to 1900 calories, Katy should be aiming for closer to 2300 calories to gain muscle most effectively.

For individuals in the “hard-gainer” category, don’t be afraid to learn that your metabolic range may be larger than the average. This energy will be used wisely by your body.


How to find the edge of your metabolic range, step-by-step

Just like training and fat loss nutrition, there is no cookie-cutter plan for those looking to gain muscle. The way we want to do this is carefully and slowly.

Here is your 5 step process:

  1. Protein - Ensure you are eating at least 1.6 g/kg of protein per day or 1.8 if you want to be extra sure.

  2. Add Food - No need to meticulously count calories (although you can if you prefer). Every week or two, slowly start to add a small amount (~50 kcals) of fat or carbohydrate dominant food to your daily intake, such as 1 tsp oil, 1 small fruit, 1 tbsp of nuts or ¼ cup of rice.

  3. Watch Your Weight, Body Composition and/or Strength – You could notice your weight rises 3-5 lbs quickly as you add and start ensuring you are eating enough every day. This is your body’s carbohydrate stores filling up. For every 1g of carbs stored in your muscle and liver there are 3g of water stored. This is not fat! Watch your strength, the mirror and have your body composition or circumferences checked regularly for greater accuracy.

  4. Continue Increasing - Keep adding to your intake of carbs and fat. If your weight makes a jump again, stop!

  5. Wait - Allow a few weeks or months and, if your weight stabilizes, continue adding again.

What else can slow rates of muscle gain?

Very low carbohydrate diets (non-ketogenic) Carbohydrate is your body’s preferred source of fuel for muscle and brain activity if it is not in a ketogenic state. Therefore, your body will do what it can to maintain your blood carbohydrate levels and it does so (partly) by converting protein into carbohydrate. If it is not receiving enough carbohydrate from food, it will break down your muscle to do this [7].

Very low fat diets Fat is an essential nutrient for many physiological processes including those that produce anabolic hormones like testosterone. Being deficient in fat can result in lower levels of these hormones which means lower rates of protein synthesis.

Too much cardio exercise Note the words ‘too much’. To maximize gains in muscle it is recommended to keep your cardio that is >20 min separate from your strength training [8]. Keep them on separate days or have at least one snack or meal in between if they need to be on the same day. Keep in mind that more endurance training will also increase your calorie needs. The same process applies as above, but your intake will likely be much higher than your cardio-less friends.

What else maximizes rates of muscle gain?

Protein timing and type

We’ve established that you need to eat enough protein. But what else can protein do for you? When should you have it? The quality?

For answers see our resource Protein for gaining muscle: there’s more to it than just hitting a daily target

Proper resistance training that regularly increases volume in a periodized way

Essentially adding more repetitions, sets and/or weight on a regular basis in the gym over the course of your training block (typically 8-16 weeks). The increase in energy will certainly help fuel this increase in volume.


1. Ensure you are consuming adequate protein (≥1.6g/kg) and energy to gain muscle fast. More than this will not result in faster gains.

2. Slowly increase food intake to find the high end of your metabolic range by following the provided step-by-step process. Ensure you are not in a deficit (losing weight) as this blunts protein synthesis reducing your rates of muscle growth.

3. Other factors for gaining muscle fast: avoid very low carbohydrate diets (non-ketogenic), very low fat diets and too much cardio exercise. Include proper protein timing and periodized progressive volume-based resistance training.

Think of it this way: The “goldilocks” of nutrition for gaining muscle fast

Forget what you know about “bulking”, as from the argument above. You don’t need to jump from 0 to 100 to make gains. In order to produce fast muscle growth, you just need to understand the concept of what we are calling, ‘the Goldilocks of nutrition for gaining muscle fast’ – not too much protein, not too much energy, but just the right amount of each.

Need help implementing this or want to be extra sure that you’re gaining as fast as you can?

Get yourself a coach or dietitian! At Unlocked we use the latest science to inform your nutrition and training so they complement one another. Contact us if you would like to team up and get close personalized guidance every step of the way to reaching your fitness goals.



  1. Garthe I, Raastad T, Refsnes PE, Sundgot-Borgen J. Effect of nutritional intervention on body composition and performance in elite athletes. European Journal of Sport Science EJSS : Official Journal of the European College of Sport Science 2013;13(3):295-303.

  2. Hector AJ, McGlory C, Damas F, Mazara N, Baker SK, Phillips SM. Pronounced energy restriction with elevated protein intake results in no change in proteolysis and reductions in skeletal muscle protein synthesis that are mitigated by resistance exercise. FASEB. 2017 Sept.

  3. FG. - Body fat content influences the body composition response to nutrition and exercise. Ann N Y Acad Sci. 2000 May;904:359-65. 2000 May.

  4. PM, RM, AB. Applications of the dose-response for muscular strength development: a review of meta-analytic efficacy and reliability for designing training prescription. J Strength Cond Res. 2005 Nov;19(4):950-8. 2005 Nov.

  5. Levine JA, Eberhardt NL, Jensen MD. Role of nonexercise activity thermogenesis in resistance to fat gain in humans. Science 1999 Jan 8;283(5399):212-214.

  6. LJ, EN, JM. Role of nonexercise activity thermogenesis in resistance to fat gain in humans. Science. 1999 Jan 8;283(5399):212-4. 1999 Jan 08.

  7. HK, PS, MM, RD, MN, GM. Effect of glycogen availability on human skeletal muscle protein turnover during exercise and recovery. J Appl Physiol (1985).2010 Aug;109(2):431-8.doi: 10.1152/japplphysiol.00108.2009.Epub 2010 May 20. 2010 Aug.

  8. WJ, MP, RM, WS, LJ, AJ. Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises. J Strength Cond Res. 2012 Aug;26(8):2293-307.doi: 10.1519/JSC.0b013e31823a3e2d. 2012 Aug.


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