How to build muscle without fat - Lean bulking macros.

Macronutrients 101

It’s that time.

You’ve decided you’re going to place your focus in to building muscle mass. Except, you don’t want to turn in to one of those people who says they’re bulking but has actually just gotten fat.

You need a well-executed lean bulking phase.

The term lean bulking is typically referring to a phase of time where adding as much muscle mass as possible is the goal, given the constraint of trying to limit fat gain only to what is necessary.

Fat gain is always going to be inevitable in a period of mass gain, however this approach aims to mitigate any unnecessary fat gain (I.e. additional weight gain that serves no further purpose regarding gaining muscle mass).

To start a lean bulk – you need to actually get lean in the first place, which should be step 1 for the majority of people (get it out of the way essentially).

These two guides I wrote may help you, if you’re struggling with that:

My complete fat loss guide.

Optimal macronutrients for cutting fat.

This article aims to cover how to implement a lean bulk in terms of nutrition. If you want an overview of how to build muscle mass (i.e. frequency, volume, intensity, exercise selection etc.) – read my article here.

Okay let’s get down to business.


Calorie intake for lean bulking:

A period of time focusing on building as much muscle as possible is going to require excess energy.

A calorie surplus.

This means that, whatever your TDEE is (your maintenance calories), you need to be (on average) consuming more calories than this to ensure that “growth” is able to occur.

For the purposes of a lean bulk, I typically recommend one increases their calories by around 10% over their TDEE. 

You can calculate all of the above using my free calculator.

You’re never going to be 100% accurate with how many calories you consume/burn, and 10% is a safe figure that would allow slow, but quantifiable weight gain.

Therefore, to ensure that the majority of this weight you’re gaining is quality weight, you would just need to be training intelligently, consistently, and progressing over time.

I appreciate it is all easier said than done, but let’s continue.

This 10% surplus rule of thumb is a safe bet for the vast majority, however let’s cover two other possible circumstances:

  • A complete beginner with a lot of muscle to gain, who is currently quite thin:
    This individual may be able to push their surplus towards 15% and be able to gain more muscle as opposed to just gaining more bodyfat.
    This will not last forever, and they should gradually transition towards the 10% over time, after “newb-gains” have begun to tail off.
  • An advanced lifter who no longer has the potential to gain a lot of muscle mass naturally (it sucks, but it happens):
    At this stage, they may want to only consume around a 5% surplus, or maybe even let their progression in the gym be the main driver of whether or not they even enter a surplus (if there’s a surplus of calories but 0 progression, it’s probably just fat gain).

Another way to try and quantify this is like this:

  1. Beginners: 1-1.5% bodyweight increase per month.
  2. Intermediates: 0.5%-1% bodyweight increase per month.
  3. Advanced: 0.25%-0.5% bodyweight increase per month.

The above are Alan Aragon’s recommendations for rate of bodyweight gain when taking into account potential for muscle growth [1].

In reality, I do think your actual weight gain may be ever so slightly higher than this – however, if you were to gain at the rates presented in the Aragon model, you could rest assured that you’re probably gaining a good proportion of muscle and minimising unnecessary fat gain (assuming you’re training effectively and employing progressive overload).


It’s a relatively slow process – but if you could zoom out and look over a longer period of time, the results can be quite phenomenal.

The point however, is to not gain weight too fast as this simply results in a longer period of time required dieting in order to rid the excess weight (fat).

Rule of thumb: We want to spend the maximum amount of time we can in a surplus/maintenance at the least, and the minimum amount of time as we can get away with in a calorie deficit.

Protein intake for lean bulking:

Arguably the most important macronutrient when it comes to muscle growth – how much protein should you consume per day?

Thankfully, I already covered this in depth in this article here about your daily protein needs.

Let’s quickly cover the important stuff.

1.5grams – 2.2grams per kg of bodyweight.

For individuals who struggle to gain weight on a bulk, opt towards the lower range.

For individuals who tend to gain too much bodyfat on a bulk, opt towards the higher range.

Higher protein intakes are fine but likely not beneficial for muscle mass gains

1.5-2.2grams of protein probably doesn’t seem very high for those who have read all the supplement-infused bodybuilding magazines that promote intakes up to 2grams per lb of bodyweight (over 4g per kg) – which there is absolutely zero research to support in terms of building muscle (they just want to sell their ovepriced protein supplement).

Remember, life as a drug-free athlete is very different to life as an athlete using performance enhancing substances – i.e. anabolic steroids resulting in considerably elevated rates of muscle protein synthesis allowing benefit from such high protein intakes.

I digress (like always).

So is there any merit to going higher on protein when in a lean bulking phase?

In terms of building more muscle mass – probably not. 

In terms of favourable body composition – potentially, yes.

This is where you need to analyse what type of individual you are:

If you are somebody who tends to always get fatter than they’d like on a bulk – then opting for the higher range of protein such as 2.2g per kg and even higher may have some merit.

Protein is satiating and has a high thermic effect, which is partially why it is so useful when dieting. For the same reasons, it can be useful in trying to fight unnecessary fat gain on a bulk.

You also do not need to worry about driving your fats and carbs too low, due to the higher calories allowing for reasonable consumption of all 3 macronutrients.

This study from Antonio et al. aimed to analyse the impact of protein over-feeding in resistance trained athletes.

Subjects were consuming 4.4grams of protein per kg of bodyweight and saw no increase in muscle mass gains compared to the control group consuming around 1.8grams per kg – however, they also saw no body-fat increase despite consuming much higher calories[2].

“This is the first investigation in resistance-trained individuals which demonstrates that a hypercaloric high protein diet does not contribute to a fat mass gain.”

Obviously, consuming this much protein just to try and avoid fat gain on a bulk is not a clever, long-term strategy (just consume less calories without the unnecessary protein) – however it helps support the claim that a slightly higher protein approach (around 2.2gram per kg) may help promote satiety and metabolism.

Are you somebody who struggles to gain weight on a bulk?

Well then it probably makes sense to eat the lower end of the recommended protein intake – you’re still probably going to build the exact same amount of muscle as with a higher intake, but you’ll have more room for fats and carbs which are much easier to consume without feeling full

For those interested in purchasing a protein supplement to help you reach your daily protein goals – I highly recommend this protein from MyProtein – Good quality, extremely good value for money & many flavours available to choose from.

Carbohydrate & fat intake for lean bulking – does it really matter?

Let’s give a really short answer here quickly:

Once you’ve set your calorie goal, and then your protein goal – however you split the remainder of your calories between carbs and fats really isn’t going to make a huge difference in terms of your gains.

I know we all want to be massively optimal, but it just really is not that big of a deal within the context of your ~10% calorie surplus.

Having said that, let’s brush over the merits of both macronutrients and where your intake should probably fall.


 A diet that is too low in dietary fat can lead to reductions in circulating levels of testosterone – not good [3] [4] [5] [6].

So, high fat bulking then because testosterone = more gains, surely?

Not quite, more like: Adequate fat bulking because inadequate fat bulking may result in very slightly reduced testosterone levels (which may or may not have an impact on muscle gains – most likely zero impact).

You see, being in an energy deficit (weight loss) seems to be the biggest culprit for reductions in testosterone levels, and sometimes separating this effect from the low-fat effect can be challenging.
The larger the deficit, the greater the impact it seems [7] [8].

You’re not in an energy deficit!

Basically, when you are lean bulking (energy surplus), the chance of your diet causing reductions in testosterone levels are far slimmer, unless your fat intake is bizarrely low. For this reason, I would barely be concerned about fat intake, assuming you’re at least hitting that “20% of total calories” floor which seems to be the threshold for healthy testosterone production.

Not to mention, a (reversible) drop in testosterone of around 10-30% will almost definitely not impact muscle growth – just sayin’.

This is why we state that it is important to achieve adequate fat intake, not an as high as possible fat intake.

On top of this, increasing the proportion of your fats from saturated fats may also help with testosterone levels, without needing to increase total daily fat intake.

This could be anywhere from 20%-40% of total daily caloric intake. Preference plays a huge part in setting the “optimal” diet. Where you fall in that 20%-40% range will be dependent upon:

  • Your taste preferences: Much prefer fattier foods? Go higher.
  • Your appetite: Struggle gaining weight? Eat more fat (and vice versa).
  • Your total caloric intake: 40% fat at 4000 calories per day is around 175g fat per day, that’s quite a lot (but not necessarily too much).
  • How you respond to foods: Trial and error, do you operate better on higher fat or higher carbs? Listen to your body, because it’s not that serious.

Bottom line is, it’s largely individual and preference/dietary adherence will always be number 1. I will say this though:

When in a calorie surplus, dietary fat is very easily stored as body fat (compared to proteins and carbs).

Therefore, it may make some sense intuitively speaking to not eat excessively over what you deem to be a necessary amount of fat, because there would likely have been additional merit from consuming those extra calories from carbohydrates instead (I’ll get to this).

When we look at studies regarding overfeeding, carbohydrate overfeeding seems to “out-perform” fat overfeeding [9] – which is partly why refeed days are done with high carbohydrates (learn more about refeeds here).


The conversion of excess carbohydrates to body fat (de novo lipogenesis) is a relatively ineffective process in humans. 

That sentence above, coupled with what I said earlier about excess fats being easily stored as body fat – well, lower fat higher carb for sure, yes?

It’s not that black and white – however, yes my end recommendation will be geared towards more carbohydrates as opposed to fats. Just bear with me.

Let’s say two individuals are consuming 3000 calories, and assume this is a 300 calorie surplus for both of them.

One follows a higher carb approach, whilst the other a higher fat.

The individual consuming more carbohydrates may have more frequent/larger insulin spikes which prevent fat oxidation (which may inadvertently promote fat gain), however they will be consuming less fat to actually store as fat during these periods of time where insulin is elevated*.

Conversely, the higher fat approach may have fewer insulin spikes, allowing for more fat oxidation; however their dietary fat intake (which can be easily stored) is higher to match this.

The end result between the two diets is pretty much identical – as their energy balance is the same (3000 calories, 300 surplus).

Insulin (in a very, very small nutshell):

*Insulin doesn’t cause fat gain – it simply allows fat to not  be oxidised (lost) when it is elevated.

Also, insulin isn’t a simple on/off switch – it simply varies throughout the day depending on what you eat. On a scale of 0-100, it is never at either 0 or 100, just fluctuates between the two.

Insulin isn’t the enemy – it also acts as a very anabolic (or rather, anti-catabolic) hormone a.k.a useful/necessary for building & preserving muscle mass.

Those who are more insulin sensitive respond better to glucose (less insulin is secreted per “unit” of glucose), whereas those who are insulin resistant  do not handle it well as more insulin is required to do the same job (this is how type 2 diabetes starts).

Therefore, someone who is more insulin sensitive will benefit from a higher carbohydrate approach (in theory), whereas a more insulin resistance individual may benefit more from an increase (decrease) in fats (carbs), which has been validated by research looking at fat loss dietary approaches [10].

So does it really just not matter then?

Well, that does largely seem to be the case. Your level of weight gain is going to be pretty much solely determined by your calorie surplus.

By hitting adequate protein you’ll be ensuring that you’re “maximising your gains” (from a nutritional stand-point), and by keeping this calorie surplus relatively small (~10%) you can be sure your keeping fat gain only to the bear minimum, hopefully.

Despite this, I’m still going to recommend an ever so slightly higher carbohydrate approach – why?

Well it’s really just splitting hairs so don’t worry about it too much (preference/adherence is still #1, choose a fat:carb ratio you enjoy), however –

1. Those who are more insulin sensitive will do better on higher carbohydrates. They will (in theory) store less fat and possibly even gain more muscle.

Two huge factors in determining insulin sensitivity are resistance training, and being lean/relatively low body fat.

If you’re about to start a lean bulk I’m going to assume you have them two factors checked. Your insulin sensitivity is probably fine – however we are all individuals with different genetics. You still need to determine if this is in fact the best approach for your body. Trial & error people.

2. De novo lipogensis (basically converting excess carbohydrates in to bodyfat) does not happen easily in humans. It takes energy for the body to convert excess carbohydrates in to body fat and so it is a low(er) priority bodily function.

3. Although some people can perform just as well on a lower carbohydrate diet – most will find that carbohydrates have an almost direct carryover to performance.

Those who have read my complete guide to gaining muscle mass and my article outlining the driver of muscle growth will know that progressive overload is the key to making gains. Therefore, being concerned with your performance is a very valid concern. I always recommend higher carbs when such an approach is feasible.

From Slater and Phillips paper: Nutrition guidelines for strength sports: Sprinting, weightlifting, throwing events, and bodybuilding – “we would consider a range of daily carbohydrate intakes between 4 and 7 g per kg body mass as reasonable for these athletes depending on their phase of training” [11].

Your lean bulking macros – summarised (and 2 bonus tips):


How many calories to consume?

Calculate your TDEE here.

Consume a ~10% calorie surplus, as stated in the calculator.

As your weight plateaus after a while (your new TDEE), increase by another 10%.

Keep weight gain slow & gradual:

  • Beginners: 1-1.5% bodyweight increase per month.
  • Intermediates: 0.5%-1% bodyweight increase per month.
  • Advanced: 0.25%-0.5% bodyweight increase per month.

Beginners may be able to push to a ~15% surplus.

Advanced lifters may have to drop to a ~5% surplus.

Protein intake:

Anywhere from 1.5g – 2.2g per KG of bodyweight.

The higher intake will likely result in no further muscle gains – however may be favourable for satiety and body composition.

If you struggle with the “bulk” in Lean Bulking – opt for a lower intake and consume more fats/carbs.

If you struggle with the “lean” in Lean Bulking – opt for the higher intake.

Fat intake:

Fats are important for hormonal balance (namely testosterone).

Intake should be between 20% – 40% of total daily calories.

Most important factor here is preference to promote dietary adherence/enjoyment – eat more fat if you prefer more fat, and vice versa.

Remember that an increase in fats results in a decrease in carbs (as protein is already set) – to keep calories the same.

Carbohydrate intake:

After setting protein & fat, carbohydrates fill the remaining daily calories.

For lean, weight-training individuals – a higher carbohydrate approach may have merit (performance benefits and assumed increased insulin sensitivity).

In this instance, opt towards the lower end of the fat intake range and maximise carbohydrate intake.

These are minor details and preference should still take precedence.

Two final strategies to help you lean bulk long-term:

1. One could consider eating in a surplus only on training days and staying at maintenance on rest days.

The additional calories on training days should be predominantly carbohydrates, as you are more insulin sensitive on these days (could even go slightly higher fat/lower carb on the rest days, but there is not currently research to support this approach being more beneficial).

2. Employ mini-cuts throughout your lean bulk. After 2-3 months of lean bulking, where you may have gained 6-10lbs or so, you may consider doing a 10-14 day mini-cut – this is just an example.

Mini-cuts are usually reasonably aggressive, to get the most bang for your buck. A 20-25% calorie deficit could be used, and then back to lean bulking.


  • [1] McDonald Lyle, What’s My Genetic Muscular Potential? 
  • [2] Antonio et al.; The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals. Journal of the International Society of Sports Nutrition2014
  • [3] Hämäläinen E, Adlercreutz H, Puska P, Pietinen P. Diet and serum sex hormones in healthy men. J Steroid Biochem. 1984  
  • [4] Hämäläinen EK, Adlercreutz H, Puska P, Pietinen P. Decrease of serum total and free testosterone during a low-fat high-fibre diet. J Steroid Biochem. 1983  
  • [5] Sallinen J et al. Relationship between diet and serum anabolic hormone responses to heavy-resistance exercise in men. Int J Sports Med. 2004 
  • [6] Volek JS et al. Testosterone and cortisol in relationship to dietary nutrients and resistance exercise. J Appl Physiol (1985). 1997
  • [7] Rossow LM et al. Natural bodybuilding competition preparation and recovery: a 12-month case study. Int J Sports Physiol Perform. 2013
  • [8] Antti A Mero et al. Moderate energy restriction with high protein diet results in healthier outcome in women. J Int Soc Sports Nutr. 2010
  • [9] Horton TJ et al. Fat and carbohydrate overfeeding in humans: different effects on energy storage. Am J Clin Nutr. 1995
  • [10] Cornier MA et al. Insulin sensitivity determines the effectiveness of dietary macronutrient composition on weight loss in obese women. Obes Res. 2005 Apr
  • [11] Slater G, Phillips SM. Nutrition guidelines for strength sports: sprinting, weightlifting, throwing events, and bodybuilding. J Sports Sci. 2011

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