Episode 40 – What is the Ideal Calorie Surplus for Muscle Gain

Key Topics Covered


It’s possible to gain muscle without a calorie surplus. Particularly when somebody is:

  • Newer to training
  • Has good genetics
  • Is on a good training program
  • Has good nutrition
  • Minimal stress
  • Has good sleep 

But even under those circumstances, it is more efficient to gain muscle in a calorie surplus. To OPTIMISE muscle growth, a calorie surplus is necessary. 

There are two main ways you can go about gaining muscle mass.  

  1. Body recomposition at maintenance calories  
  2. A small calorie surplus

Downsides of too Large/ Small Calorie Surplus 

  • Too large = excessive fat gain 
  • Too small = slower than necessary muscle growth 
  • Study titled “Effect of nutritional intervention on body composition and performance in elite athletes” – 39 athletes either ate an “ad libitum surplus” or a set 500kcal surplus.  
  • Over the course of the study the 500kcal surplus group gained just over double the body weight, a tiny bit more lean mass and a LOT more body fat.  
  • I often point to the above study since back on the day on bodybuilding.com it was common advice to tell people to go into a 500kcal surplus. But studies like the above are a solid example of why that is not often a good move outside of very specific cases. 

Caveat – A Calorie Surplus can Increase your Energy Expenditure 

  • This happens to a different degree in different people.  
  • But when your body has access to more energy, it is likely to start burning more through:
    • Increase in the thermic effect of foods (we burn calories digesting food) 
    • Increases in both planned and incidental activity – if we eat more, we might have more energy and therefore push harder in training, training more or do things like take the stairs instead of the elevator  
    • Increase in our BMR due to metabolic adaptation – just as your metabolism can down regulate when you are in a deficit, it can upregulate in a surplus  
    • Changes in body composition and calories burnt through producing more muscle mass  
  • One study overfed participants by 1000kcal per day, 6 days/week over a 100 day period.
    • The average gain was 8.0kg, but the range was 4.3-13.3kg.  

An Interesting Study

  • “Is an Energy Surplus Required to Maximize Skeletal Muscle Hypertrophy Associated with Resistance Training” – one of the most boring and densest studies I have ever read. Went super into detail about trying to pinpoint things like the energy cost associated with building muscle explaining that this could actually be a large portion of why some people require larger calorie surpluses to gain size at the expected rate, in addition to changes in NEAT and TEF.  

Theoretically, this study is the most useful study for this topic – but it is so hard to find useful takeaway points in it. 

  • Their recommendation was that people start with a surplus between ~300-500kcal per day and monitor body composition from there and make adjustments over time. 

Practical applications 

1) Beginner: 250-500kcal surplus (or 1-2kg per month) 

2) Intermediate: 125-250kcal (or 0.5-1kg per month)  

3) Advanced: 50-125kcal (or 0.2-0.5kg per month) 

  • I also prefer to think of it in terms of monthly weight gain than calorie surplus size due to:
  • 1) How small the surplus gets and how little margin for error there is because of that
  • 2) The whole concept of changing energy expenditure 

This can sound slow, but muscle gain becomes a slow process as you get closer to your potential. Advanced, natural lifters are forever chasing that last 1-2kg of muscle growth. Going quicker than this ends up just guaranteeing a lot of body fat is gained.  

Useful Links/ Resources

Studies Mentioned:

Relevant Blog Posts: