The Lean Bulk: Maximising Muscle Growth with Least Fat Gain

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Ok, so you’ve trimmed down to a decent body fat percentage using one of many cutting/dieting techniques, and are now looking to enter into a growth phase.

You want to pack on as much muscle as you can for your age and natural genetics, whilst minimising fat gain. You are not alone! You and everyone else wants the holy grail of muscle gain whilst maintaining their leanness.

Build Muscle & Burn Fat Meme

This article lays out the reality that most men (and women) will face when prioritising lean muscle growth, and gives the most practical real-world recommendations to Lean Bulking.

The Ugly Truth of Muscle Growth

There are some universal truths we must orient around before going any further. I’ll opt for brevity throughout, so you can quickly get to the info that matters most:

  1. Testosterone matters – This means 15-25 year olds will do better than 50 year olds in building muscle if all else is matched. Testosterone declines naturally with age once in your twenties, and can be further depressed based on lifestyle factors
  2. Anabolism matters – Sustained and appreciable muscle growth requires being in a net-anabolic state through time. That means having sufficient calories, protein and micronutrients to support a net-growth of muscle tissue
  3. With Muscle comes Fat – If you are in a net-anabolic physiologic state, all tissues get fuelled for growth and repair. That includes adipose tissue – aka body fat. How much fat, however, is within your control
  4. Lose Fat, lose Lean Mass – If you diet down, you’ll have to be in a sustained caloric deficit, allowing you to catabolise body fat tissue. Problem is, lean mass will also take a hit – it will be broken down too. How much actual muscle you lose, is within your control
  5. Lean Mass is not Muscle Mass – Lean mass includes all non body fat weight, including bones, muscles, organs etc… and water and glycogen within your muscles. Lean mass can fluctuate a lot between dieted lean and bulking. Muscles look ‘fuller’, because they are!
  6. You Cannot Convert Fat – Sorry, it doesn’t work like that. You must decide. Lose the fat (with some lean mass loss), or gain a little muscle (with some extra fat)
  7. Newbie Gains stop – Ugh! After 6-12months of proper strength training, this honeymoon period of gains slows right down. During this period, you can gain muscle whilst dieting. You’ll likely see half your natural gains potential in this year alone
  8. It Takes a Long Time! – Expect 3-5 years of consistently effective training and nutrition to reach close to your muscular potential. Probably longer. After that, it’s a loooong road to small improvements

Right, now we got that out of the way, lets briefly understand what happens during a diet.

What Happens During a Diet?

In any serious successful effort to lose weight, you would have persevered through a sustained calorie deficit over several weeks or perhaps months. Whether you opted for a non-dramatic mild deficit, a more aggressive blitz cut with refeeds, a fasting blitz cut or any other form of diet protocol, your body would have hunkered down into a period of perceived famine.

In an effort to preserve life, your metabolism would have slowed, non-essential movement would have been reduced, and easily accessed energy would have been tapped into. In addition to the inevitable reduction in carbohydrates, you would have seen a noticeable reduction in water and glycogen weight within your muscles.

Furthermore, as your body will be in a net-catabolic state (more breaking down than building tissue), you will have lost some inevitable muscle mass. To minimise muscle wastage – strength training, eating at least 1g of complete bioavailable protein per lbs of bodyweight, refeeds, and dieting for as short a period as possible are good recommendations.

Simple Anabolism vs Catabolism

Let’s now talk about post-diet bulking…

What To Expect After Dieting Down?

So, once the day comes to end the diet and return to your TDEE (Total Daily Energy Expenditure) – i.e. the amount of calories to maintain your new weight, your body will embrace the apparent ‘feast after the famine’.

You will tip out of a chronically net-catabolic state and enter homeostasis and then into a net-anabolic state (more building of tissue versus breaking down). Your body will be primed to soak up all the nutrition and energy it can muster, as it rebuilds back up its energy reserves. If you are increasing your carbs too, the net effect can be quite a bump in scale weight.

Diet rebound
Steve’s diet rebound: saw 5 lbs rebound even when eating at maintenance calories for first week of Lean Bulk

Using myself as an example, If I lose ~14lbs of weight in a cut, taking myself down to say ~185lbs at 7-10% body fat, I can expect my scale weight to bump 3-5 lbs within the couple of weeks of exiting a diet. That will happen even if I stick to maintenance calories, and keep carbs still relatively low.

A lean bulk one month in
One month into lean bulk: After initial bump, scale weight normalises with a slight upward trajectory

Over the course of the first month of maintenance and/or a lean bulk, my weight will likely increase by 5lbs or so from baseline. Why? Replenishment of glycogen and associated water into your muscle bellies, extra gut weight, and some growth of adipocytes (body fat cells).

These numbers will be dependant on your height, muscle mass, overall bodyweight and sex. Irrespective, expect to see your weight rebound by several pounds as your body attempts to replenish itself to healthy levels. It will be overall body weight, with just a touch going towards your waist/belly.

What is Lean Bulking?

As mentioned, almost everyone who wants to increase muscle mass wants to do so whilst minimising fat gain, or naively expects to lose body fat during this time.

Getting back to reality, we must accept that with any committed muscle hypertrophy goal, we will inevitably gain some unwanted body fat. How much you gain depends on how you decide to bulk.

In an ideal world, you would perfectly fuel a net-anabolic state to the calorie, leaving negligible surplus calories to be stored as body fat. The reality is, adipocytes enter into an anabolic state as well as muscle cells, meaning this ideal physiologic state of no extra calories doesn’t really exist. Some calories will inevitably get diverted into fat cells.

And let’s not forget that we must ensure we’re in a net-anabolic state over the course of a week and a month. How many calories you need to make this happen changes per day based on the uniqueness of that days activities, combined with your complex unique physiology and metabolism.

thread that needle
Threading the needle: It’s a fools errand trying to match your calorie intake to your ever shifting TDEE

It would be a huge waste of training energy (and hope) if you were accidentally running on a sustained calorie deficit in an attempt to perfectly thread the needle of muscle growth without fat gain. No one wants to to work like a dog in the gym and actually lose muscle mass!

So, in response to the above desire and realities, Lean Bulking is your best solution. Defined as TDEE +5-10% on a daily basis, with most people shooting for +10%. So, if your average training week daily TDEE is 3,000kcal, you would be shooting to consume 3,150-3,300kcal.


People often ask how to manage daily caloric goals between Training and Non-Training Days. There are two approaches:

  1. Weekly TDEE / 7 – Using your historical energy burn and calorie counting data in a typical training week, add up Monday through Sunday and divide by 7. Take that average and multiple by 1.05 – 1.10
  2. Undulating Targets – Alternatively, using your historical data, identify your average Training and Non-Training TDEE. Multiply both number independently by 1.05 – 1.10 to get your Training and Non-Training daily targets

Please Note: These above recommendations assume you have been historically tracking daily energy expenditure with fitness trackers such as an Apple Watch, and counting daily consumption with a tool such as MyNetDiary. If not, using a TDDE Calculator with a little real-world trial and error using the above tools will help you know your numbers within a couple of weeks.

TDEE Calculator Results
TDEE Guesstimate: Even if you don’t have historical data, is within +/-5%

The most important thing is, if you’re bulking, you should feel satisfied with the amount of food you eat. Your body tells you if you are under nourished in terms of calories and nutrients.

Personally, I like to get that feeling everyday to ensure anabolism, that’s why I adjust my calories between resting and training days. I want to get enough stimulus throughout the week, without feeling deprived, as well as not getting into bad overeating habits on non training days.

What Muscle & Fat Gain can I Expect?

This is where the muscle meets the road! The question that we all care about most.

In ideal circumstances, you can expect to see muscle gain in line with the below table for a guy. Women can expect approximately half this progress. Remember, your age, lean mass weight and testosterone status will absolutely play a role, as will the effectiveness of your strength training effort and recovery protocol.

Sorry if you are disappointed, I understand. Especially if you are busting a gut in the gym. However, we are all in the same boat, unless steroids are involved, or you are a genetic freak. That said, incredible physiques are frequently created naturally. Commitment and perseverance can create stellar physical results.

What about fat, I hear you ask

Well, this is another “it depends”. This time, the dials at play will be diet choice and quality, age, and most importantly… quantity of food consumed.

After the first 3-4 weeks post-diet, where your body was replenishing energy stores, you should settle into a predictable and slow rise of body fat gain that is tolerable and contained. In my experience of lean bulking, a 1:1 to 2:1 ratio of Fat Gain to Muscle Muscle Gain is a very good result.

So, if you are an intermediate lifter and are able to max out at your top end of 0.5lbs of muscle gain in a month, expecting 1lbs of fat gain is totally reasonable, and probably the best result you can expect.

Mathematically, it stacks up too, albeit this is back of an envelope stuff…

Naturally the science is not clear on how many calories you actually need to maximally fuel daily muscle growth without fat deposition. Why? We are infinitely complex and varied organisms. So, when we’re talking about lots of estimate numbers with reasonably high margins of error, trying to be precise on imprecise data makes no sense.

That said, if your TDEE is 3,000kcal, then you will be in a daily surplus of 300kcal. Approximately, let’s say you need a ~150kcal of energy to support daily maximal muscle growth. That would leave a monthly non-muscle growing surplus of approx. 150×30 = 4,500kcal. With approximately 3400kcal in a pound of body fat, would would expect to put on 1.3lbs of fat.

It seems that Novice and even Beginner lifters can push to to the 1:1 Fat Gain to Muscle Gain ratio on a Lean Bulk, whereas trained lifters need to accept a ratio closer to 2:1.

The lean bulk progress
LEAN BULK Weight Gain: After the initial bump (which was Xmas time!), I settle in at 1.5-2lbs per month

Irrespective of training age and experience, if the weighing scales are shooting real fast, you are likely laying down more fat than muscle.

WORK IT OUT: Take the above Muscle Gain Potential and use the 1:1 for less trained and 2:1 for the well-trained lifters to estimate your absolute max monthly bodyweight increase. If you are not Lean Bulking AND not training hard enough… well, you know what will happen.

Optimising Your Lean Bulking Experience

Alrighty. You are almost set and ready to start your (likely multi-year) Lean Bulking phase.

That said, it would be remiss of me to not talk about nutrition quality, and specifically adequate levels of complete bioavailable protein.

When it comes to retaining or building muscle mass, you need a good amount of bioavailable amino acids (aka proteins). Protein is the building block of all tissue generation, growth and repair in our bodies, and it’s essential to human health that we get enough.

Protein Amount

As a general rule of thumb, aiming for 1 gram of protein per pound of bodyweight is an easy and reasonable number to aim for. If you are sufficiently overweight or obese, you may need to lower this number to an achievable target, or consider using your lean mass weight instead.

Quality: Complete Proteins

Now, quality of Protein does matter. Protein is not one thing – in actual fact it’s short hand for Amino Acids, of which there over 200 leveraged within the human body! That said, there are 20 most commonly used amino acids in the body, of which nine are essential (can only get them through food we eat).

You need to make sure your protein sources in total per day/week contain a full animo acid profile. Moreover, you should be thinking about favouring the most bioavailable protein sources, otherwise your portion goals will need to increase further.

Quality: Bioavailable Protein

The most bioavailable and naturally complete Protein sources are all animal-based, with Eggs topping the chart. Whey protein (milk derivative) and Beef are close contenders. If you opt for a nutrient-dense diet where animal based products feature at the centre, you will be in the most advantageous spot.


After daily Protein Intake and Protein Quality are addressed, you may wish to further optimise around the edge with Protein timing and extra Leucine supplementation. These are NOT the big rocks, but will add a couple percentage points of extra protein synthesis.


Protein Timing

As a general guide, try to get some protein 1-2 hours before and after you workout, as well as decent hit of protein in your evening meal. I opt for this approach, but I don’t get precious about times and optimal doses. Feel free to google around for many opinions of ‘optimal’.

Well Timed Leucine

As Leucine most robustly triggers protein synthesis out of all the Amino Acids, it is recommended to get an extra hit of Leucine just before your workout, with at least 30-60mins between this and your prior meal. Again, this is of marginal benefit.

How Long Should I Lean Bulk For?

Generally, you should consider lean bulking for as long as you are deliberately training for hypertrophy and muscle growth goals. 3-5 years is a likely timeframe to go from untrained to a physique reaching 90% of your potential – if you train with complete conviction.

But of course, you will not want to Lean Bulk throughout without any breaks. Firstly, you’ll eventually reach a fat mass that you can no longer tolerate. Secondly, you body needs periods of deprivation to bounce back anabolically. And thirdly, being overweight and/or constantly overfed is not a healthy state from a longevity and disease prevention standpoint.

So, you’ll probably want to cut again in about 3-5months of a Lean Bulk. In 3-4 months you’ll probably not like your waistline… albeit you’ll still be leaner than most if you started at 8-10% body fat.

How you cut, and for how long, takes you right back to the top of this article.

For me, with long term growth being the number one priority, plus (naturally) not enjoying being on a diet, I opt for dramatic and quick weight loss. I do a Blitz Cut or Fasting Blitz Cut, between 3-5 weeks. I’ll strip off about 12-14lbs of weight, maintain for a few days, and then straight back into a Lean Bulk. #rinseandrepeat

Steve Katasi Fat Loss Journey
BLITZ CUT: One fast approach to cutting in just a few weeks

Now… go enjoy those Lean Gains!

Steve Katasi 2 year body goals finale
STEVE: Check out my journey over two years, as a walk the talk of lean bulking…

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