The question seems trivial on the surface: How much should I eat? If you dig deeper into it, determining your energy demand can get quite complicated. Countless different formulas try to calculate what can only be guesstimated in real life. Therefore I show you an easy way to do the calculations yourself and how to make sure the numbers fit your goals.
Disclaimer: I am neither a physician nor a nutritionist. If you are going to change your diet drastically, seek the counsel of a dietary professional first. That said, I am only giving you information that has worked times and times for a wide variety of people and is considered save in the evidence based fitness world.
We need to calculate our energy intake to make better decisions of what exactly we are eating. This process is commonly called tracking and nowadays best done via an app. There are countless tracking apps out there, just choose what seems to fit you, most of them are pretty good.
I firmly believe that everbody should at least at some point in her life learn to track. It can be an eyeopener! We simply have no grasp of how energy dense (and devoid of protein) many of our favourite foods are. Sadly the food industry makes this problem not exactly easier, but that is an entirely different topic for another time.
Even though I think tracking is great, we still have to consider it has limitations and potential dangers. Tracking forces you to focus a lot on food: What to eat? How much to eat? Which combination of foods to eat? This can lead to a difficult relationship to food in the long term. Because of this, tracking is a tool to be used for certain periods of time, not a way to live your life. Transitionsing back to intuitive eating should always be the end goal!
First of all we need a starting point for our energy intake. Later you can always adjust it depending on what the scale shows. More on this later in the article. The calories you need every day come from the following areas:
- Resting metabolic rate (60-70%): this is everything your body needs for survival without doing anything.
- Diet induced thermogenesis (8-10%): the energy your body uses for digestion.
- Physical activity (20-30%): includes exercise and non-exercise activity like fidgeting.
As you can see, energy demands of physical activity are not that high compared to the energy your body needs just for maintenance. Our body is very efficient at moving and it is very easy to overestimate the amount of calories burnt by exercise. Crappy fitness media makes this even worse as they like to promote (yet another) totally awesome workout that burns 600kcals in 60minutes. Please, don’t believe this! I know, it is tempting to reward yourself with some ice cream after a tough workout, but the truth is that you probably only spent a few hundred calories, which is more like two bananas. Sad, but true.
Okay, now as we are all down to earth with our calorie expectations, let’s take a look at how to calculate your energy demands. There are several different formulas out there, some use your body-mass-index, some your lean body mass, some are even more complex and include characteristics like gender. But all of them are flawed! There is no formula, that calculates your energy demand, they are only estimations. As they are all inaccuare to some degree anyways, we might as well pick a simple formula:
Calories(kcal) = Bodymass(kg) * 22 * Activity Factor
The activity factor (AF) is a measure of how active your lifestyle is. Most of the time it is just a measure of how often you train per week, as the general population isn’t very active outside the gym anyways. However, if you have a physically demanding work, feel free to up your activity factor accordingly.
- no or very little training/activity = AF 1,2
- 1-3 days of training = AF 1,375
- 3-5 days of training = AF 1,5
- 6-7 days of training = AF 1,725
- multiple training sessions per day and/or extremely active lifestyle = AF 1,9
To give you an example: if I (~85kg) go to the the gym 4 times a week, while not being overly active otherwise (bear-mode), I need around 2805kcal (85 x 22 x 1,5). This is the amount of calories I need to neither gain or lose body weight. Which, of course, raises the question: how many calories should I add/leave out if I want to lose/gain weight? Glad you asked, let’s take a look.
First of all, let’s get absolute numbers out of the way. What I mean by this are recommendations that often float around in fitness media like “eat 500kcal less everyday to lose weight”. While such numbers are a often a good place to start for most people, they can be wildly inaccurate for certain individuals.
Think of a 50kg woman who wants to lean down to chiseled abs for a bikini shooting. Let’s call her Mary. Training 4 days a week and working an office job allows her 1650kcal. If she cuts on a 500kcal deficit, she drops her energy intake by ~30%. That’s a lot! On the other side, we have a highly motivated, but severly obese male at 180kg, working as a mechanic and training 6 times a week. His name is Peter. He needs 6830kcal to maintain weight. Cutting 500kcal from his diet doesn’t even put him into a 10% deficit! While not everybody has to lose bodyweight as fast as possible, a too slow approach unnecessarily lengthens the cutting phase.
How aggressive should you diet? Well, this is different for everbody. The more advanced (leaner) you are, the less aggressive you should diet to protect you from losing too much muscle mass. Which means in conclusion that the more body fat you carry, the harder you can diet:
- Overweight: 30-50% deficit; 1,5% weight loss per week.
- Intermediate: 20-40% deficit; 1% weight loss per week.
- Advanced: 5-25% deficit; 0,7% weight loss per week.
- Elite: 2,5-7,5% deficit; 0,5% weight loss per week.
That’s a lot of numbers, right? Well, let’s come back to our examples mentioned above. Mary is already quite lean, so we classify her as “advanced” and assign her a 15% deficit. This means she is cutting at 1400kcal (1650 x 0,85), eating 250kcal less every day. This is quite far from the “minus 500kcal”-rule mentioned above. Peter, on the other hand, is classified overweight, so we put him to a 40% deficit. This gives him 4100kcal, a 2700kcal deficit, which is again far away from the 500kcal-rule.
I hope these examples have convinced you to think critically about the numbers that are being thrown around in common fitness media. Now you can do the calculations yourself and make a better decision. Always remember: it isn’t as important where you start, as it is important how you adjust!
The same principles that are true for losing weight can be applied for gaining weight. Again, we don’t want to use absolute, but relative numbers. When gaining weight, we have to use much smaller numbers because building muscles is a very slow process. If we put on weight too quickly, we gain unnecessary large amounts of body fat, which we would have to diet down later for longer periods, leaving less time in a calorie surplus or having to cut more frequently.
Contrary to weight loss, we are not looking at body fat to determine the surplus/weekly weight gain, we are looking at how muscular advanced you already are. This is, of course difficult to exactly measure, but a general estimation is good enough. The more advanced you are, the slower you can build muscle and the slower you have to bulk.
- Novice: 5-10% surplus; 1% weight gain per week.
- Advanced: 3-7% surplus; 0,5% weight gain per week.
- Elite: 1-3% surplus; 0,25% weight gain per week.
What to do with those numbers? Well, it is pretty easy. You weigh yourself every day, note it, and at the end of the week you calculate an average of those seven days. If your weight went up as appropriate to your muscular level, you are fine. Else, you need to adapt. Too little weight gain = eat more. Too much weight gain = eat less. It’s really that simple.
A quick side note as we are talking of building muscle: I regularly stumble upon rates for muscle building on fitness media, which are usually absolutely overblown! I don’t know where those numbers come from, but for the average, chemically unassisted office Joe, they are far from realistic. Which is very bad, because it breeds false expectations of progress. Please forget those numbers and focus only on the journey, not the outcome! As long as you put your best into it, you will see good results.
Tracking is a tool everybody should learn to wield as it teaches a better understanding of food. However it it to be used for certain goals, not as a way of life!
- Use the simple formula above to calculate your maintainance calories.
- Choose if you want to cut or bulk.
- Determine a deficit or surplus that is adequate to your level of body fat/muscle mass.
- Track your body weight, calculate a weekly average and see if the scale moves in the right direction and at your individual speed.
- Adjust calories if necessary. Rinse and repeat!
I hope this article was helpful for you and made it clearer how to calculate your energy intake. Next we will take a look at how to fill those calories out with protein, fat and carbs, a.k.a. the macros. If you are interested, subscribe to the Beary Email Liste below to make sure you don’t miss it!
Meanwhile, love life, lift and eat well!