I often hear athletes say:
“I eat a lot, but just can’t gain weight.”
“I’m not sure if I’m eating enough to fuel my performance goals and recover properly.”
“I eat well, but still can’t get rid of this extra body fat.”
The issue here is one of specificity.
YOUR BODY IS LIKE A CAR
To over-simplify it, the body is in some ways, like a car, in that it requires a certain amount of fuel and a certain type of fuel.
If you were telling someone to fill your car with fuel, you wouldn’t just tell them to “Put a lot of fuel in”, or “Use good fuel”, you would tell them how much to put in, based on how much traveling you were planning on doing, and you’d tell them the exact type of fuel needed (diesel or petrol, for example) based on which type of fuel was right for your specific car.
Similarly, leaving the fuelling of your body open to vague terms like “A lot” or “Well” can lead to sub-par results.
Energy Balance
Of course, the quality of food you fuel your body with is important, but in the same way that even high-quality diesel won’t get you far if you don’t have enough of it, the best quality of food won’t be enough to fuel you if you don’t eat the right amount of it.
For car fuel, the numbers we use are usually litres.
In the case of energy for our bodies, we use the measurement of calories.
This can refer to the energy we put into our body through food, and the energy we use through exercise and daily life.
These two aspects form what’s known as the energy balance equation.
If the amount of energy you take in is greater than the amount you put out on average, the extra energy will be stored, and you will gain weight over time.
If the amount of energy you output is greater than the amount you take in on average, your body will use its energy stores (from body fat, for example) to get the energy it needs, and you will lose weight over time.
If the amount of energy you take in is the same as the amount you put out on average, and you are supplying enough energy to fuel your body (no more, no less), you will remain the same weight over time.
The Performance & Physique Sweet-Spot
As an athlete, whilst gaining or losing weight might be important to you depending on your current goals, it’s only one part of the equation.
Fuelling your body is another part.
Eating in too much of an energy deficit (i.e. eating excessively fewer calories than your body uses) in pursuit of dropping body fat can cause you to feel drained in training and under-recovered.
Eating in too much of an energy surplus (i.e. eating excessively more calories than your body uses) in pursuit of muscle gain or simply fuelling properly can lead to unwanted increases in body fat.
Instead, you want to hit the sweet-spot between improving your physique and fuelling your performance as an athlete.
That will require a level of accuracy around your food intake.
This may require that you track your food intake, through an app like MyFitnessPal or Cronometer for example, and adjust your calorie intake based on the upcoming calculations.
But Your body is Not a Car
Although we can draw some conclusions about the body, based on its previously-mentioned similarity to a car, it isn’t a car, and doesn’t work in exactly the same way.
One way in which this is true is that, for the body, one side of the energy equation can affect the other.
This is a separate topic for a different article, but I’ll give a couple of quick examples.
If we eat in a calorie deficit for a period of time, and therefore lose weight, we will have less body mass to carry around, and therefore will be using less energy on a daily basis to carry this now-lighter body, meaning that we will probably need to eat slightly less to lose the same amount of weight.
On the other end of the scale, if we eat in a surplus over time, and gain weight, we now have more body weight to carry around, and our energy output increases, potentially creating a situation where we need to eat more in order to gain the same amount of weight.
We also may unconsciously start to move more, train harder etc, as our body “finds stuff to do” with all this extra energy (although storing fat may still be one of those things).
Based on that, plus the fact that training load and activity levels change throughout the weeks and months, it would be impossible to calculate an exact figure for how much energy you will be expending, and therefore how much you should be eating.
So, we use the best estimates we can, and adjust over time.
Getting Specific: Calculating Your Estimated Calorie Requirements
In order to calculate your recommended calorie intake, there are many equations used in the scientific literature and in practice, and they can all get quite complicated.
Here’s one that’s basic enough to calculate for yourself, whilst giving you a good estimate.
Step 1: Multiply your bodyweight in kg by 22-24:
BW (in kg) x 22 for those with relatively low activity outside of training.
BW (in kg) x 23 for those with moderate activity outside of training.
BW (in kg) x 24 for relatively high activity outside of training.
Step 2: Multiply the answer from step 1 by an activity multiplier, based on your training load:
If you are sedentary (little or no exercise) : ‘Answer from step 1’ x 1.2
If you are lightly active (Train 1-3 days/week) : ‘Answer from step 1’ x 1.375
If you are moderately active (Train 3-5 days/week) : ‘Answer from step 1’ x 1.55
If you are very active (Train hard 6-7 days a week) : ‘Answer from step 1’ x 1.725
If you are extra active (Train very hard Everyday & physical job or train 2x/day) : ‘Answer from step 1’ x 1.9
Step 3: Decrease or increase based on bodyweight loss/gain goal:
For weight-loss:
Decrease by 10-30% (towards the lower end if performance is a priority whilst losing weight, towards the middle if weight-loss is a priority whilst still performing well, and towards the higher end if you have a lot of weight to lose.)
For weight-gain:
Increase by 5-10% (towards the lower end if staying lean is a priority, towards the higher end if weight-gain is a priority)
You could increase the deficit/surplus beyond these recommendations in certain situations, but these are good starting points.
Example Calculation
Let’s take, for example, an 80kg footballer, who trains 3 times per week, with two gym sessions, is relatively active (has an office job, but does a decent amount of walking around the office and has a 15 minute walk to and from work) and wants to gain weight.
Step 1: Bodyweight in kg x 23
80 x 23 (based on his moderate activity level)
= 1840 kcal
Step 2: ‘Answer from step 1’ x Activity Multiplier
1840 x 1.55 (based on him/her training 3-5 times per week)
= 2852 kcal (this would be his/her estimated maintenance)
Step 3: ‘Answer from step 2’ + Percentage based on weight goals
2852 + 10% of 2852 (based on weight gain goal)
2852 + 285
= 3137
= 3150 kcal (rounded)
Adjusting & What to Expect
As mentioned previously, the values calculated here are estimates, and therefore won’t be exact.
In order to get closer to your exact caloric requirements, it’s important to track how your boydweight changes and adjust your intake targets based on those changes.
Here are some guidelines as to what to expect or aim for:
Fat-loss: Aim to reduce body weight by 0.5-1% per week. (e.g. Losing 0.4-0.8kg per week for an 80kg athlete. Towards the lower end if performance is a priority, towards the higher end if weight-loss is a priority)
Maintenance: Aim to remain the same body weight as time goes on.
Muscle Gain: Aim to increase body weight by 1-2% per month. (e.g. Gaining 0.8-1.6kg per month for an 80kg athlete. Towards the lower end if staying lean is a priority, towards the higher end if weight-gain is a priority)
If you aren’t making that type of progress based on your goals, presuming you are actually consistently hitting your calorie targets, then adjusting your calorie intake 5-10% either way and tracking progress will eventually lead to you hitting your goals for weight change/maintenance.
It may take a few increases or decreases to find your sweet spot, but you’ll get there.
It’s also crucial to remember that bodyweight fluctuates daily and for that reason, it is important to look at the trends over a period of weeks, rather than each day.
Body composition and fuelling your performance will also be affected by your training (most specifically, resistance/weight training for muscle gain/maintenance) and the macronutrient breakdown of your calories (protein, fat and carbohydrate) which you can calculate using this article.
Article Written By Conor O’Neill
Conor O’Neill is a Nutritionist, Strength & Conditioning coach, Psychologist, and Author.
He has helped 1000+ everyday athletes to pursue excellence in their physique and performance through optimising their nutrition, training, and psychology.
You can find out more about The Everyday Athlete Program by going to everydayathleteprogram.com/coaching.