How many calories do you need to build a pound of muscle?
Simple question this one. Everyone knows that a pound of fat contains 3,500 calories, so if you want to add a pound of muscle, you’ve got to eat at least 3,500 extra calories. Right? Wrong.
This is the first comment usually chucked out on bodybuilding.com, and it’s wrong for several reasons. A pound of muscle doesn’t contain fat. Sure, there’s a little bit of fat stored within the muscles (called intramuscular fat, it’s why Wagyu beef is so damn tasty), but the predominant contents of muscle are water (70%), protein (22%) and trace amounts of carbohydrates, fat and minerals. So given that water has zero calories, and protein has 4 calories per gram, that should mean we need only around 400 calories (of protein) to build that pound of muscle. Chuck in some fat and carbs and we’re up to around 800 calories. IS that all it takes? NO! That’s another simplistic way of looking at muscle building, and it’s all wrong too.
FACT: The energy contained in muscle is not the same as the energy it takes to build muscle
This is the most commonly overlooked element of the puzzle above. If we want to “build” a pound of fat, do we just have to eat a pound of butter? Or does it “cost” energy to take that pound of butter and turn it into another notch on your belt buckle? Similarly why can’t we just eat a pound of another animal’s muscle and turn that into a pound of our own? Let’s take a deeper look.
The Seven Fundamental Questions for a One Pound Muscle Mass Gain
2.) Can we use energy already ‘stored’ inside the body as fat to build muscle?
3.) How much energy does it cost to break that fat down and turn it into useful fuel for muscle growth?
4.) How much energy does it cost to break down the food we eat and turn that into a pound of muscle?
5.) How will we know whether this over-eating will result in muscle gain or fat gain?
6.) Can we actually measure whether we’ve build a pound of muscle or a pound of something else entirely?
7.) How many calories do you need to build that pound of muscle?
So what are the answers?
Question 1. How much energy is contained in one pound of muscle?
This one is simple – we looked at it above. 800 calories is as good an estimate as any (note that different muscle tissues will have different calorie levels). Building a pound of bicep muscle is not the same as building a pound of heart muscle. But as we’ve discussed above that isn’t the whole story. It obviously costs more calories to build the muscle than the muscle actually contains.
Question 2. Can we use energy already stored in the body as fat to build muscle?
It would also be lovely if my next door neighbour’s cat crapped gold nuggets on my lawn rather than cat sh*t. Sadly it’s not going to happen.
The reason it doesn’t work is because your body is not good at making protein out of fat and carbohydrates. Protein is an essential nutrient – this means we have to eat protein in our diet in order to survive. We can’t eat something else then make it into protein ourselves. So the fat in your fat cells can’t turn into protein in your muscles.
But it CAN supply you with energy, and if you do your training, eating and nutrient cycling right then you can use fat from your fat cells for fuel on rest days and gain muscle (through overeating) on training days. That’s the principle behind my Lean Mass Gains Made Easy protocols, and it IS possible to build muscle whilst losing fat if you’re in the “Body Recomposition” category (between 10 and 15% body fat).
Question 3. How much energy does it cost to break that fat down and turn it into useful fuel for muscle growth?
OK, so we can’t use the fat directly to build muscles, but we can still liberate it from the fat cells for use as fuel on our rest days (if we set up the diet right). How much energy does it cost to “liberate” that fat from the fat cells and prepare it for use by your body?
Well, not a whole hell of a lot. But given that we can’t use the pound of fat to build a pound of muscle, it’s rather irrelevant here (other than to note that liberating a pound of fat from your fat cells doesn’t actually ‘waste’ much energy).
Question 4. How much energy does it cost to break down the food we eat and turn that into a pound of muscle?
This is a more interesting question. Because of a process known as the “thermic effect of feeding” we know that different macronutrients ‘cost’ different amounts of energy to break down and then rebuild once inside your body.
We know that we need to eat at least 100g of protein to build the pound of muscle (454g in a pound, ~ 22% proteins in muscle, therefore around 100g of protein per pound). But does all of the protein we consume actually get turned into protein in muscles?
No. Sadly, protein is pretty wasteful as a nutrient (which is another good reason to eat it – check out this post on macronutrients to find out more). Your body burns about a quarter of the energy of protein just trying to process this nutrient. This is called the Thermic Effect of Feeding (TEF).
Carbohydrates burn up around 6% of their energy through TEF, fat around 3% (in case you were wondering, alcohol burns a stately 0%).
The reason that protein is so ‘wasteful’ is the high energy cost of breaking the protein into its constituent parts (amino acids) and then rebuilding the links once inside your body. A high protein meal will stimulate whole body protein synthesis (note I say whole body here, your muscle protein synthesis is a more specific measure). There is also an energetic ‘cost’ of transporting those amino acids around your body and into the cells that need them (just like you need to put gas into a truck to deliver goods in the real world). A further ‘cost’ is incurred building the machinery in your cells that will assemble the amino acid building blocks by rebuilding these links between each amino acid (just like it costs money to buy cranes and diggers when creating a new building).
The theoretical values obtained show that building one gram of new protein inside a cell will cost up to 1 calorie per gram of protein created. Awesome – we’re getting somewhere. A pound of muscle has around 100g of protein within it, so does that mean we only need to overeat by 100 calories to build that pound of muscle? No, sadly not.
Just because a pound of muscle contains around 100g of protein doesn’t mean that’s all you need to build to create that pound of muscle. There’s a whole load of other elements to a muscle cell that need to be created. Plus there’s the entire supporting framework needed to hold that muscle in the right place (connective tissue) and supply it with blood (capillaries).
Coupled with that, the food we eat won’t always go where we want it to go. Some of our overeating (especially of carbohydrates) does wasteful things we don’t want it to do (like stimulating your sympathetic nervous system – essentially making you more active). Some of it will be excreted by your body (protein gets turned into urea, which is urinated out – something to think of when you’re buying a large tub of whey protein). And some of the elevation in whole body muscle protein synthesis in response to a meal is purely repairing damaged and old proteins that need to be replaced. There’s clearly a lot more going on than the simple theoretical amount of calories required for building the protein contained within a pound of muscle.
Let’s look in more detail.
Question 5. How will we know whether this over-eating will result in muscle gain or fat gain?
This is of paramount importance to bodybuilders, but also to anyone else who cares about their general body shape and health. After all, we’re putting in some serious work in the gym and we want to make sure we get the right results. So what dictates whether your calorie consumption will end up on your biceps or end up on your ass? And can you control this?
The answer is your hormones. They are primarily responsible in the body for taking messages from one type of cell to another. Normally one set of cells is busy “measuring” what sort of stress your body is under, then creating and releasing hormones into the bloodstream to “tell” the other tissues what’s going on and how to respond. We see this easily in a commonly known hormone – insulin. The pancreas is where insulin is made. Your pancreas measures how much glucose is in the bloodstream. If the level is above a certain threshold it releases insulin in order to reduce the amount of glucose that’s circulating. Insulin achieves the response by telling other cells (fat and muscle importantly) to “suck in” some of that glucose from the bloodstream and put it to use.
So can you control your hormones? Can you pass on a message to send your calories into your muscle cells but not into your fat cells? Actually, yes you can.
Exert some control!
You want to be controlling Insulin, Growth Hormone and Testosterone, IGF 1 and 2 and others besides. And there are two fantastic ways to do this.
The first is through resistance weight training. Check out the training section of the site for more information here. Essentially by putting regular stress on your body through barbell exercise (and making use of progressive overload) we are able to change the hormonal response of our muscle tissue. How? Because the stress of resistance exercise is measured in the cell and signalled to the nucleus (where the DNA sits – kind of a control centre) by cell signalling pathways. The most commonly talked about one is called mTor – essentially a protein within your cells that is able to measure what is happening in the muscle cell and send internal signals to boost growth (or not). It also measures external signals and responds to insulin and net energy balance, as well as the amino acid Leucine.
The net result of the mTor stimulation (and other cell signalling too) is to up-regulate muscle protein synthesis, and to increase the cells ability to take up glucose from the blood (by increasing the number of glucose transporters on the cell boundary). Under the stress of resistance exercise your muscles also release more Growth Hormone and your testes produce more Testosterone.
Lifting heavy weights changes how your muscle cells respond to hormones and how they respond to nutrients in the bloodstream. After you lift weights your muscles will be more likely to take in nutrients from the blood than your fat cells. So if you over eat post workout, more of the food you consume will go where you want it (your muscles) and less will go where you don’t (the fat on your ass).
It’s all about the timing
All of this is a really fancy way of saying “lift weights to get bigger” which bodybuilders have known for years. The point for this article is that the weight lifting is causing improved responses to nutrients in the bloodstream. Simply put – a muscle that has lifted weights will be more responsive to nutrients than one which has not. This means that we can time our over-eating to coincide with our training and more of the calories we consume will end up in our muscles. Because we know that a trained muscle is more likely to take up nutrients than one which has rested we should aim to over-eat at the times our muscles want food and under-eat at a time when they do not.
What else controls the hormones?
The second mechanism that boosts muscle cell responsiveness to nutrition is fasting. It’s growing more and more in popularity amongst those that seek true lean mass gains, and there’s a good reason why. Daily intermittent fasting boosts muscle cell insulin sensitivity. (As a side note, fasted training boosts the mTor muscle building pathway mentioned above more than training when fed too). This boost in insulin sensitivity is “free” – you don’t have to hit the gym or buy a supplement to get it. You just have to skip breakfast and follow the nutritional strategy I lay out in the free course here.
This increase in muscle cell insulin sensitivity means that on a day-to-day basis you are more sensitive to glucose in the bloodstream. Your muscles will actively take up more of the nutrients placed into your blood, and will enable you to store less of the calories you eat within fat cells.
This is backed up by studies showing improvements in body composition when fasting even in the absence of a calorie deficit (reference), and by studies on fasting during Ramadan (when Muslims see beneficial effects on body composition and blood markers, but normally eat a feast style diet of foods high in carbohydrates and fat (reference). Simply put – fasting changes your hormonal responses to ensure more of your food goes to your muscles and less goes to your fat.
Question 6. Can we actually measure whether we’ve build a pound of muscle or a pound of something else entirely?
This is another confounding element when looking at the effect of overfeeding to muscle growth. Unfortunately it isn’t one that has an easy answer to. In my Lean Mass Gains Made Easy course I spend a long time discussing the different mechanisms to measure body composition. To save you the time of reading all of that, the upshot is that it’s pretty difficult to get an accurate measurement of both body fat and lean body mass using even the most sophisticated scientific instruments (and zapping your body with X-rays). Even the best methods to measure body composition have about a 3% error rate.
If you think about that, and look at a 200lb male, you could have 6lbs of error one way or another. Given we’re talking about a 1lb gain of muscle mass, that’s well within our margin of measurement error (even if we took a really light female, we’d still struggle).
Add to that the problem of what has been built. With DEXA (one of the best body fat estimation tools) you get readouts of your Lean Body Mass, your Fat Mass and your Mineral (bone) mass. Whilst we can at least see whether the weight gain is down to fat gain, lean tissue gain or bone gain (which isn’t possible using a technique like skin fold callipers) we still don’t know if the lean tissue gain is muscle or other elements of lean mass (like tendons and other connective tissue).
Ultimately there is no way round this problem. We have to recognise that a 1lb change in anyone’s mass happens on a daily basis anyway (due to hydration levels, food in the stomach etc) and that measuring a true 1lb gain of muscle mass is not a very easy thing to do. That said, we can still make educated guesses based on bigger mass gains over longer time periods, so I’ll move away from this question and on to the next.
Question 7. How many calories do you need to build a pound of muscle?
I know it’s taken a while to get here, but as you can see from the previous 6 questions, this question is not as simple as it looks. It’s hard enough to accurately measure calorie intake and calorie expenditure when examining fat loss. It’s even harder when looking at muscle gain. It takes a long time to build muscle in humans (outside of rank beginners, you’ll be doing well to put on half a pound of muscle a week). And given the difficulties posed by question 6, it’s a tough problem to solve.
So what’s the answer? Well, research from the paediatrics (where they can easily measure weight gain in infants, and have a better control over calorie input and output) gives figures of 5 calories per gram of tissue (note, any tissue – not just muscle) built (reference). Better still, studies on adults place the range between 7 and 8 calories per gram of tissue built (reference). Adults will always have a harder time growing bigger because we don’t have the same rampaging hormones anymore (unless you’re juicing). The 8 calories per gram is for building Lean Body Mass, whereas the 7 calories per gram is looking at total mass gain (showing it ‘costs’ less calories to build fat than it does to build muscle – no surprises).
If we take the top end of that spectrum, and realise a pound is equivalent to 454g, then we’re looking at up to 3,600 calories we need to consume to build one pound of Lean Body Mass in the body. This is actually remarkably close to the value of energy contained in one pound of fat (3,500 calories) that we started out with. It turns out that the simplistic view on muscle mass gain is right, even if it’s right for the wrong reasons!
Putting it into practice
So it’s all well and good doing the theoretical gymnastics above to create a value for how many calories you need to eat to build a pound of muscle, but what does that mean in the real world? How do we use that to change our diet? And how to we put that into practice so we build lean muscle mass rather than fat?
The simple advice is to moderate your eating and calorie consumption so you’re only over-eating by around 250 calories per day whilst trying to gain muscle (shooting for a half pound of muscle gain per week). But that really is a simplistic look; because you won’t benefit from the nutrient timing processes mentioned in question 5. It’s also quite obvious that different types of trainee can add muscle at different rates (with beginners growing at up to a pound a week, but experienced trainees taking up to a month to pack on the same amount of muscle mass).
The more educated method is to understand how quickly you can truly build muscle depending on your body type, training experience and gender. Then make an effort to time your calorie and macronutrient consumption with your training to maximise the benefits and ensure those over consumed calories turn into muscles. Combine that with the practice of daily intermittent fasting and you’ll be on track for lean muscle gains in no time.
The problem with that approach is its complexity – it requires effort and math to get the numbers. That’s why I wrote Lean Mass Gains Made Easy. I also released a complementary excel calculator to do all the calculations for you. All you need is a set of bathroom scales and a tape measure to plug in the numbers. If you care about building lean muscle mass you should grab your copy today. Click here to get started!