In our last two blog posts about muscle building, we explored changing body composition, how fat loss and muscle building interact, and under what conditions.  We also covered exercise in greater depth. 

You can find them here: 

In this post we are going to look at nutrition.  This post is for anyone that wants to build muscle or tone up.  Toning is a product of fat loss and muscle building.  Quite often it’s a good idea to start by building some muscle before we go on to do some work on fat loss (but not always).  If you are interested in building some muscle or toning then this post (and the last two) are for you.


At PinkPT we believe that all bodies are good bodies, and we deliver training and advice to people with any goal for themselves.  At PinkPT you decide your goal and we coach as required.  Rather than this post being generic advice that we think everyone should be following, it’s simply an open response to questions about nutrition for muscle building that we regularly get.

In this post we will cover:

•Protein requirements for hypertrophy

•Carbohydrate requirements for hypertrophy

•Fat requirements for hypertrophy

•Calories and meal timing for hypertrophy

Protein requirements for hypertrophy

Protein is probably the macro nutrient (nutrients that we require in large amount and that can be used for energy, namely Fat, protein and carbohydrates) that is focused on most when building muscle.  This is because the protein we ingest literally becomes muscle in our bodies.  Protein is broken down into amino acids and these become the building blocks for repairing muscle and gaining muscle mass. 

The optimal daily amount of protein needed seems to be between 1.3-2g per kilogram of bodyweight (a 75kg man would need 97.5-150g protein a day).  That is to say that eating less protein than this might mean that you aren’t recovering efficiently from weight training and potentially aren’t building muscle as efficiently as possible.  Eating more than this would mean that the extra protein is purely providing fuel for activity or being stored as fat (expensive fuel).


A key amino acid in this process is leucine.  Leucine is the sole stimulator of protein synthesis, and is absolutely crucial to muscle hypertrophy.  In fact ingesting leucine on its own post exercise is almost as effective as ingesting every essential amino acid including leucine. 

The magic number here is 3g in each meal, particularly post work out.  This takes a little effort if you aren’t used to eating high protein meals regularly and forms a good argument for taking protein shakes.  There is 3g of leucine in a chicken breast, 5 eggs, or 200g of firm tofu, beans and pulses are much lower and large amounts would be required.  For me, I like eating, and 5 eggs post work out is absolutely fine with me.  For those who don’t like that idea a good quality whey protein shake can easily provide 3g of leucine post work out.  You can have a little look at your other meals and make sure you are hitting that 3g requirement there too.  If in doubt, Google your protein source and check how many total grams you would need to provide 3g of leucine and 30g of protein (depending on your daily goal, based on 1.3-2g per kg of bodyweight) and serve that up for breakfast, lunch or dinner.

The post exercise protein window

The narrative goes that the protein synthesis window is 30-45mins long and begins immediately after exercise.  In this window protein synthesis is highest and protein should be consumed in this window.  Well… yes and no.  Protein synthesis is at its highest but ingesting protein in this window vs any other time of day doesn’t change the result on its own. You need carbohydrates too.  We’ll cover why when we go on to talk about carbohydrates. 

When we talk about optimal, it probably is best to eat protein post work out (maybe even pre work out too) but the importance of this has been widely exaggerated.  The reason for which is mostly to sell protein shakes and bars.  It’s hard to sit down and eat a whole chicken breast and something carby immediately after a work out and if you believe it is absolutely essential to get that protein in (and carbs) then you are going to buy a shake.  It’s not essential, it’s probably optimal, but if you are determined to go through your muscle building journey without supplements then you absolutely can and really effectively too.


•1.3-2g of protein per kg of bodyweight per day

•3g of leucine every meal

•Protein shakes make things easier


Carbohydrates are massively important for muscle building.  It is nearly impossible to build muscle on a low carbohydrate diet.  There are a couple of reasons for this. 

Carbohydrates are our preferred fuel source during intense exercise (like lifting weights), protein is a back up.  If you don’t have enough glycogen available (stored carbohydrates in your muscles and liver) then your body will use protein as a fuel.  Your body breaks down the protein into its components and you can no longer use the amino acid to build muscle.  In fact in cases where protein isn’t available either then your body will break down your own muscle and you will use that for fuel.  You can train hard in the gym and end up losing muscle mass.

The other reason is that insulin is needed for lucine to act as a hypertrophic regulator and insulin is produced in response to carbs.  Insulin and lucine work together to build muscle in the human body.  The caveat to this is that relatively low levels of insulin are needed to trigger this response and more isn’t better (until you get to pharmaceutical levels of insulin that you can’t achieve through diet).  So a little carbohydrate close to exercise might increase the efficiency of muscle building, but this has been massively exaggerated in the name of selling post workout shakes with added simple sugars.  There is no proof that spiking your insulin levels dramatically post workout with sugar will increase protein synthesis beyond what a few grams of carbs would achieve. 

The main reason to replace carbs post work out remains for protein sparing reasons.  If you replenish your carbohydrate stores you are much less likely to use the protein for muscle building and not for a fuel replacement for the glycogen lost in preforming your work out.

Optimal carbohydrate requirements for a muscle building diet are very hard to estimate.  It purely depends on how many calories you are burning both in your work out and in your day generally.  It also depends on how much fat you are eating too, if you aren’t eating much fat then the need for carbs go up and vica versa.  Carbohydrates as with protein provide 4kcals of energy per gram.  If you consume above the level you are using then the extra will be used for replenishing glycogen, and assisting in muscle building, after that the rest will be stored as fat.  Eating too little carbohydrate will mean that you aren’t effectively building muscle, eating too much will lead to you gaining fat.  It’s best to allow for some fat gain whenever you are trying to build muscle.  Unless you are a hypertrophic hyper responder some fat storage always happens.  As a guide 55-60% of your total calories should come from carbohydrates.  If you are doing a lot of cardio alongside your weights routine then this will almost definitely need to be higher.  If you try this for a few weeks and you feel you aren’t gaining any muscle then you can slowly increase that figure.


•Carbohydrates are protein sparing and crucial for muscle building

•Start at 55-60% of your total calories coming from carbohydrates (higher if you are expending more energy through cardio, walking, an active job etc)


Fat like carbohydrate is an efficient fuel source.  The two of them work together to provide the energy for daily life.  Carbohydrate provides more fuel during intense exercise and the fat does a bit more work the rest of the time. 

Dietary fat requirements don’t specifically go up when you are trying to build muscle but total calorie demands do, so it’s probably best just to up your dietary fat a little in line with your total calories.  There is a significant metabolic cost to building muscle, and total calories need to go up. 

If protein is set at 1.3-2g per kg of bodyweight and carbohydrates are at 55-60% of your total calories, fat just needs to pick up the slack.  Probably around 20-30% of your total calories.

Total calories

It is not essential to be in a calorie surplus in order to optimally gain muscle (for most people) however if you are in a deficit then you will really struggle to gain any muscle at all, therefore it’s best to aim to be in a slight surplus. 

Muscle building itself also has a metabolic cost, muscle building is calorific work.  Your total calories will need to be significantly higher than they would be to maintain your current bodyweight and body composition. 

The following mechanisms also affect calorie demands during muscle building.  Much more so if you are new to exercise or new to following a hard resistance work out routine:

•Energy cost of resistance training

•Increased metabolism post exercise

•Increased cost of protein turn over (breakdown of muscle and protein synthesis in building new muscle

•Overcome increase in dietary induced thermogenesis (the energy it takes to dives more food)

•Increase in NEAT (non exercise based activity) due to metabolically active tissue.  Trained muscles burn more calories at rest

•Increase in total NEAT due to less time spent sedentary

A good guide for a total calorie goal is 45kcals per kg of bodyweight (75kg person needs 3375kcals).  I would recommend that you start there and adjust as required.


•Calorie demands go up during muscle building

•Being in an energy deficit will inhibit muscle building

•A good total calorie goal to start with would be 45kcals per kg of bodyweight


•Aim for 1.3-2g of protein per kg bodyweight

•Ingest 3g leucine with every meal

•Eat 55-60% of your calories through carbohydrates

•Start with 45kcals per kg of bodyweight

•Eating close to training helps

•Protein shakes make things easier but are not essential