Setting Energy Balance (Calories in vs out) & Optimal Rates of Body Weight Change
Whether your goal is muscle gain, fat loss, or performance enhancement or weight maintenance for your sport, the single most important piece of the nutritional puzzle is getting your energy intake right.
Not macros, not timing, not avoidance of alcohol, gluten, dairy or any other specific food, calorie intake.
In this post I’ll tell you:
- How to choose appropriate fat loss targets based on your current body fat percentage.
- How to set muscle gain targets based on your current training experience.
- How to calculate your energy intake for those targets defined above
- Why energy calculations are only a ‘best guess’ and need to be adjusted.
- How to adjust your calorie intake to get back on target if things don’t go as planned.
This is the longest in the series, but the most important. Get this right and you’re two-thirds of the way there. I hope you find it useful.
Fat Loss & Muscle Gain Fundamentals
(to check we’re on the same page)
People generally have one of two goals, fat loss or muscle gain. Though everybody wishes for both, generally that is only achieved by beginner trainees due to the favourable nutrient partitioning they experience.
Late stage novices, intermediate or advanced trainees will have to chase one goal or the other.
Those choosing fat loss (known as ‘cutting’) will lose body weight. Those choosing muscle gain (known as ‘bulking’) will gain body weight. As energy balance determines whether weight is gained or lost, it is the most important part of the fat loss puzzle.
Deficits can (and arguably should) be greater than surpluses.
- Fat can be lost quicker than muscle is gained, so those cutting will experience quicker and more obvious visual changes than those looking to gain muscle.
- Gaining muscle requires the building of new tissue and connections in the body. It takes time and requires patience. – Think of building a house versus burning one down. The former takes time, the latter much quicker.
- An excessive energy surplus when bulking (stuffing yourself with food every day) will lead to muscle growth, but also excessive and unnecessary fat gain. As we are looking at nutrition from a physique and secondly performance perspective, we want/need to curb this. We will therefore refer to a muscle gain phase as a “slow-bulk” rather than bulk.
- Therefore, the energy deficit to burn fat can (and should) be greater than any energy surplus to build muscle.
Diet should determine whether you are in an energy deficit or surplus, not training.
It’s easier and more effective to control the energy balance through diet, i.e. eating more or less, rather than moving more or less.
Training should be determined by goal, not used to address the energy balance equation.
Adding in extra weight training (this includes metabolic conditioning circuits) will interfere with the recovery balance from your workouts. When bulking this threatens to steal from your gains. When cutting, the increased energy and recovery demands will add to systemic stress, and those knock on hormonal effects will negatively affect fat loss.
Cardio, while it can be used to help create calorie deficit required for fat loss, it should never be the primary means of doing so.
Don’t try to outrun your mouth.
Calculating Your Calorie Needs – Just an Educated Guess?
The likely range for your maintenance caloric needs, needs to be calculated first.
Step 1. Calculate your BMR
I like to call BMR your ‘coma calories’. – The energy intake you need, should you fall into a coma, to maintain your body weight. There are a variety of formulas, all of which produce a guess at best, however we need a figure to work with. Please choose a different formula if you wish.
Metric BMR Formula* (*Harris-Benedict)
Women: BMR = 655+ ( 9.6 x weight in kilos )+( 1.8 x height in cm ) – ( 4.7 x age in years )
If you’re obese then the above formula will overestimate your BMR, and if you are very lean then the above formula will underestimate your BMR. If you have an idea of your body fat percentage then you’re best using the Katch-McArdle BMR Formula.
Katch-McArdle BMR Formula:
BMR (men and women) = 370 + (21.6 X lean mass in kg)
Step 2. Adjust for Activity
You need to add an ‘activity multiplier’ (x1.2~x1.9) to your BMR depending on your lifestyle/training.
It’s essential to realise that any calculation will just be a best guess, which is why I used the words “likely range” to describe the calculations above. This is because spontaneous physical activity (a.k.a. NEAT, written about here) – fidgeting, moving around, propensity to take stairs vs elevator etc. – will vary greatly between people.
This means that two 6ft, 200lb males, with the same 15% body fat and training regimes may find their maintenance calorie needs vastly different. One guy may need 2500kCal a day to maintain his weight, the other 3250kCal.
No calculation can take into account these individual NEAT differences. However, we need a starting point, so we make a calculation regardless.
How do we therefore get our calorie intake right?
- 1. Set weight loss targets based on current body fat percentage, and weight gain targets based on training status (beginner, intermediate, advanced).
- 2. Calculate the theoretical deficit or surplus needed to achieve that.
- 3. Adjust energy intake upwards or downwards accordingly based on how the scale weight* changes over a few weeks of consistent implementation.
More on each of these below.
*For ease and simplicity we’ll assume that fat loss is linear and any scale weight change reflects pure fat loss in a cut, or weight gain (muscle and a little fat) in the slow-bulk. – More on this in, How to Track Your Progress When Dieting.
Cutting: Choosing Fat Loss Targets and Setting Calorie Intake
How much fat can I lose per week?
Recall from the article How and When to Manipulate Your Macros that there is a theoretical limit to how much fat can be released from the fat stores in a single day, and this is inversely proportionate to how lean you are. If you go over this limit, then you will lose muscle mass, regardless of whether you keep your protein intake high (specifics covered in next article, Macros).
Simply put, fatter folks can get away with greater rates of fat loss than leaner people.
Maximum fat loss recommendations depend on a persons body-fat percentage rather than total body weight. If you shoot for the following you should be ok for preserving muscle mass:
|Body fat %||Loss /week|
|30%>||~2.5 lbs / 1.1kg|
|20-30%||~2 lbs / 0.9kg|
|15-20%||1.25-1.5 lbs / 0.45-0.7kg|
|12-15%||1-1.25 lbs / 0.45-0.6kg|
|9-12%||0.75-1 lbs / 0.35-0.45kg|
|7-9%||0.5-0.75 lbs / 0.2-0.35kg|
|<7%||~0.5lbs / 0.2kg|
The above figures are my guidelines, they are based on observation not theoretical limits.
Obese people significantly over 30% body fat will be able to lose more per week without muscle losses, but I don’t advise it for skin elasticity reasons.
Short people should shoot for slightly less; taller people may be able to go slightly higher.
Feel free to go with a lower rate of fat loss if you find it more sustainable. Just because you can lose more, doesn’t mean you should if it makes your life miserable.
How to adjust your daily calorie intake for the cut.
You may have heard the ‘rule’ that it takes 3500kCal to burn a pound of fat. (Though not flawless it’s a good guide so we’ll roll with it.)
If based on that chart above you have determined that a ‘safe’ rate of fat loss for you is 1lb a week, then you’ll need to have a calorie deficit of 3500kCal for the week to do that.
This can be as simple as reducing calorie intake by 500kCal a day each day, regardless of training. Or, as per Martin Berkhan’s Leangains set up, you can fluctuate your intake to have more on training days than on rest days for the theoretical recovery and nutrient partitioning benefits.
Even if you choose to add this layer of complexity, you still need to maintain the same weekly deficit. (So for example, if you are training 3 days a week that could be: maintenance +500kCal on training days, maintenance -1250kCal on rest days.) – This should answer all those questions like “Well, what if I choose to train 4 or 5 days a week?”
It’s important to note here that the 3500kCal rule thus 500kCal deficit/day in theory.
Also, alongside the individual energy requirement variances that make the initial maintenance calculation just a best guess, we also have the issue of NEAT swings with dieting. Basically some people will experience greater swings in their NEAT than others when their calorie intake changes upwards or downwards. – Which partially explains why some people tend to struggle and claim of being very lethargic when dieting, but others don’t. Also, there’s the issue of metabolic adaptation, which we covered in, Why You Need To Make Adjustments As You Diet.
If your eyes just glazed over there, don’t worry about it, the science isn’t necessary to understand the implementation of the method. All you need to know is that things aren’t always going to work out as the math said. You need to track your progress and adjust your calorie intake upwards or downwards according to the scale weight changes to get yourself back on target.
You’re best to take the average of 3 or 4 weeks weight change.
Slow Bulking: Muscle Growth Expectations and Setting Calorie Intake
Unlike fat loss, where body-fat percentage determines how quickly we can lose weight, rates of potential muscle growth are determined by how advanced someone is with their training.
Whereas fat can be lost relatively quickly, muscle gain happens slowly but. If you are bulking you’ll need to be patient to see changes.
Classifying Training Experience
Though different experts in the field have different ways of calculating muscle gain potential, they all agree that beginners can gain muscle more quickly than more advanced trainees. Which brings us to a sticky area – how to classify someone’s training experience/status.
Lyle McDonald does it by “years of proper training”, which I personally think is too open to misinterpretation (aka: fantasy thinking).
Alan Aragon, Martin Berkhan and Eric Helms go by Beginner, Intermediate and Advanced categorisations.
If you’re a lifter that has been focused on gaining strength in the barbell movements, or has put those movements at the core of your workouts, then you can determine your training status fairly objectively using Martin’s guidelines here, section Progress and Goals.
If not, check out Lyle’s guidelines here.
Muscle Growth Potential
Alan gives rate of muscle gain potential per month as a percentage of body weight, Lyle and Eric as a range of pounds. I like to go with the latter as it makes the math simpler. So here it is:
Training Status | Gains/month | Energy Surplus/day
Beginner | 2-3lbs | ~200-300kCal
Intermediate | 1-2lbs | ~100-200kCal
Advanced | 0.5lbs | slight surplus
- Don’t sweat the math. The above daily energy surplus recommendations are just recommendations. As with cutting there will be individual variances (section above: The Caveat). So choose a surplus, stick with it, track, and adjust your calorie intake upwards according to the scale weight change.
- Height consideration. Shorter men should shoot for the lower end of the ranges above; taller men the upper; women for around half (unless you’re built exceptionally big for a lady).
- We’re talking about real muscle mass increases, not the increase in water weight people experience when increasing their carb intake or volume of training. (It is this that explains the slew of people in forums claiming they gained 10lbs of muscle in a month after taking supplement X.)
- For advanced trainees, muscle growth on this level is so small that it can be very tough to track. It is probably better to just shoot for a slight surplus, and then gauge progress by strength or rep increases in the main compound movements. This way though you won’t necessarily see the differences in the mirror, measurements, or scale weight, you can be sure that structural changes are actually taking place.
Adjusting Calorie Intake When Weight Doesn’t Change As Planned
For a Cut: Decrease calorie intake by 200-300kCal/day, or ~5-10%. (If weight is lost too quickly, there is a risk of muscle loss, so increase calories.)
For a Slow Bulk: Increase calorie intake by 100-200kCal/day, or ~3-6%. (If weight is gained too quickly, you’ll have put too much fat on, so decrease calories.)
Remember to take into account water weight fluctuations, and always consider 3-4 weeks worth of data before making any changes.
That’s it, by far the biggest piece of the puzzle.
When it comes to questions such as, “Can I eat X?” first and foremost consider whether it fits within your calorie intake targets – macronutrient targets are the secondary consideration.
Of course, to minimise any muscle loss when cutting and minimise any fat gain when slow-bulking you’ll need to get those macros right. – We’ll cover this in the next post. If you’d like to be notified when that comes out, click like on our Facebook page and it’ll pop up in your feed.
Feel free to critique, show love, or ask questions in the comments. Yes, I could have made this a lot more complicated/detailed, but have tried to find a balance between including the necessary theory & math, while keeping it accessible.
If you think your friends may benefit from reading, please share it. - Andy.