If you’re already convinced in the magic around tracking your food and progress, you will need to know how to start calculating your numbers and to get a good kickoff of your journey. This is where science comes into play and that, in my opinion, is one of the most exciting parts. If you’re puzzled between few things, choose the one that is backed up with science. Not that the other one might not work for you, but scientifically proven methods will almost inevitable make you succeed.
So, understanding the need of calorie deficit for fat loss or calorie surplus for building muscle is great, but I’m sure you have asked yourself “Okay, but how much do I need?!”.
First, The Basics
You already know energy balance and metabolism determine what is happening with your body and physique. If you need a little reminder, here you can find it.
So, how much calories you need?
Calorie is just a unit of energy, and not tiny creatures sewing your clothes tighter and tighter every night.
1 kilocalorie (kcal) equals 1000 calories.
Kilocalorie is also called food calorie, but people usually use calorie as short for kilocalorie.
Let’s divide people’s goals into 3 types – losing fat, maintaining their current weight and building muscle/gaining weight.
3 Main Fitness Goals
Calorie deficit – eating less calories than your body needs to maintain your weight. Hence, you will lose weight, which might be mostly fat, but it could also be lean body mass. This depends on your food choices. Calorie deficit is the only necessary condition for losing body fat. How you will create a deficit, is, however, another story.
Maintenance calories – as simple as it sounds. These are the calories your body needs to maintain your current weight. Not going up, not going down. Slow body recomposition is possible over long period of time.
Calorie surplus – consuming more calories than your body needs to keep the same weight. This results in increasing body weight, as it’s preferably to do it in a way which builds up more muscle tissue than fat tissue. If you want to build more muscle, this is your deal.
There is always an exception, though, which concerns mostly people who are just beginning to workout, to lift weights and are newbies in general. For these people it’s more likely possible to build a little bit muscle while shedding fat at the same time.
There has been some research on building muscle and losing fat at the same time with professional athletes and people who workout regularly and they show that it’s also possible for non-newbies to achieve such results. Yet, this is not a focus here, so I’m going to write another article on the subject, trying to find as much evidence as possible. Just stick to the basics for now.
Then, Maintenance Calories
In order to know where and how to make changes you need to know first the calories you need for keeping your current way. As you know from my previous article about Energy Balance & Metabolism, we are going to calculate your TDEE (total daily energy expenditure).
TDEE = BMR + PA (NEAT + Exercise) + TEF
This is what we need to calculate for you to start. There are many calculators (even online: this one works great www.tdeecalculator.net), but no matter which one you choose, you should always keep in mind that this is just an estimation. It might not be 100% accurate, but it’s a great starting point.
Some equations use Lean body mass, because 2 people might have the same weight, age and height, but to look completely different because of differences in muscle mass and body fat percentage:
Fat Mass (FM) = Body weight × body fat percentage
Lean Body Mass (LBM) = Body weight - Fat Mass
Using only the scale is not a great way of measuring progress, because muscle tissue is denser than fat tissue. This means that at some point you could even weight 3-4-5kg more but to look a loooot smaller, lean and ripped if you have lost the extra fat and have built muscle.
PS: Building 4-5 kg of lean muscle tissue is extremely difficult for a woman and requires hell of a lot time, dedication and right progressive workout program. A mean – A LOT!
There are different ways for measuring body fat including DXA scans, calipers, underwater weighing and many more. All of them will give you a different result which doesn’t necessarily mean that they are inaccurate. If you pick up any method, just make sure you always use the same one under the same conditions. Don’t switch between measuring tools, because you wouldn’t know how your body responds to the changes in your nutrition.
Find Your BMR
The Katch-McArdle Equation:
BMR = 370 + (21.6 x Lean Body Mass (kg))
The Cunningham Formula:
RMR = 500 + (22 x Lean Body Mass [LBM] in kg)
Men: (10 x weight in kg) + (6.25 x height in cm) – (4.92 x age) + 5
Women: (10 x weight in kg) + (6.25 x height in cm) – (4.92 x age) – 161
The Revised Harris-Benedict Equation
Men: BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) – (5.677 x age in years)
Women: BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) – (4.330 x age in years)
The Aragon RMR Equation
25.3 x lean body mass in kg
11.5 x lean body mass in pounds
NOTE: There’s a margin of error with all of these equations!
Add Your Activity Factor
After you’ve estimated your BMR, you should apply your activity level to estimate your total energy expenditure. Multiply your BMR by one of the following:
1.2 - Sedentary
no exercise, desk job
1.375 - Lightly Active
desk job, light exercise 3-5 days/week or you don’t exercise but you’re on your feet for most of the day.
1.55 - Moderately Active
moderate exercise 3-5 days/week with active job or hard workouts with desk job. You might also have extremely demanding job but don’t workout at all.
1.725 - Very Active
hard workouts 6-7 days per week and relatively active job
1.9 - Extra Active
very hard daily workouts and physically intensive job or 2/day training)
Let’s say a lady has BMR of 1360. She works as an accountant, but also visits the gym 3-4 times a week and tries her best to have a really nice workout, but it’s still new to all of this. I would calculate her TDEE by multiplying her BMR with 1.375 and her TDEE will result in 1870 calories a day.
What about TEF?
In most formulas calories are already high enough to worry about TEF, which is in general very small, but if you really, really, really want to calculate absolutely everything:
BMR x Activity Score X 1.1 = Total Energy Expenditure
Create a Calorie Deficit for Fat Loss
We can take the above example with our lady and her 1870 calories for maintenance. In order to eat in a calorie deficit she needs do crease her total daily calorie intake.
We have to be absolutely sure that is her maintenance, which would mean to have her consuming 1870 calories for at least 2 weeks to see whether her body and weight change.
I usually prefer weighing myself daily and taking the weekly average to be as accurate as possible in my tracking. Because women tend to have fluctuations in their weight due to hormones and their menstrual cycle, stress and other factors.
Usually a drop of 15-20-25% in the total daily calories is enough to achieve a moderate deficit that will not stress you a lot. As other general rule a drop of 500 calories is more drastic and works for a big part of people. For our example lady, this would mean a drop between 280 - 374 – 468 calories a day. Again, this rate is highly dependent on the dieter’s lifestyle, how she feels with so many calories, whether she recover well and so on.
I recommend a weekly drop of 1% body weight or something between 0,5 and 1 kg a week. This numbers depend on how much fat to lose some has. A 55 kg lady will more likely lose fat at a much lower rate as someone who wears 30 extra kilograms.
Remember that you don’t need to go too drastic! If you see your weigh dropping with 0,3 kg a week, that doesn’t mean you have to increase your fat loss rate the following week! Stay consistent with your diet and give your body a little time.
If you’re not losing any weight for a couple of weeks that would mean that you’re not in a deficit. Either your maintenance is lower than your calculations or you’re making mistakes somewhere with food tracking.
Also, these are just numbers. And these numbers will always change. As your weight changes you will need to reevaluate your calorie and macro needs. But as much as you want to be super precise with food tracking and measuring, that is impossible. Food labels aren’t always correct, kitchen scales too. Same type of foods in general have slightly different nutritional value. There are no both things in the world that could be exactly the same.
You need a basis which you will adjust over time. It’s a trial and error process. And no personal trainer can give you the perfect macros and calories for you! only you can because you know yourself best and you know how you feel during all your daily activities.
Macronutrient Targets: The Math
Let’s get deeper because fat loss requires a deficit, but still it’s not a good idea to eat only brownies and french fries within your calorie intake, if you want to have an appealing body shape.
So, here it is. The king of macros, because I think no one has created a diet that excludes protein (yet!). And I hope it won’t happen. Ever!
Protein contains 4 calories per gram.
When you’re in a deficit is good to keep your protein intake slightly higher, so you can maintain as much LBM as possible.
The daily recommendation for protein intake is somewhere between 1.5-2 g per kg body weight if you’re not in a deficit.
I would recommend a protein intake somewhere between 1.8 - 2.8 gr per body weight when in a calorie deficit.
So if a 55 kg lady needs to eat 1600 calories in a deficit, her protein per day will be 55*2.2(choosing relatively high amount of protein) which will result in 132 grams of protein per day
132 g * 4 calories = 528 calories from protein a day
When we subtract 528 from 1600, we see that she has 1072 calories left for fats and carbs.
How she will distribute her calories, is a personal preference. Some people prefer foods higher in carbs, other prefer foods higher in fats.
You shouldn’t exclude any of those macronutrients, and my advice is to start experimenting with different quantities and see how you feel during the day, observe your energy levels, recovery and sleep and if necessary, adjust them.
Carbs contain 4 calories per gram.
Let’s say our lady example prefers to eat foods higher in carbs and would like to start with around 150 g carbs, which is 600 calorie and leaves her with 472 calories for fats
Fats contain 9 calories per gram.
So, 472 divided into 9 is about 52 calories a day.
It’s good to know that you should keep your fat intake somewhere in the range of 20-30% of your total calories, as in a lot of hormonal process are involved fatty acids.
Step 1 - Find Your Maintenance Calories
Use any formula or online calculator and define your starting point. How accurate is it, doesn't matter. Start somewhere, stay there for 2-3 weeks. See if this is your maintenance level. If it is, adjust for a deficit. If it's not, adjust ti find your true mainenance.
Step 2 - Create a Reasonable Deficit
A deficit of 500 calories a day works fine for majority of people. You can try a 15-25% deficit depending on your energy, recovery and hunger. Don't go too aggressive for too long, as you might crash quickly and ruin your result just by binging for a few days.
Step 3 - Calculate Your Protein Intake
Keep your protein slightly higher when in a deficit. SOmewhere between 1.8 and 2.8 grams per kilogram body weight. 1 gram of protein contains 4 calories.
Step 4 - Distribute Carbs & Fats
Distribute the left of your calories according to your personal preference. Experiment how you feel and how your body changes. Carbs contain 4 calories per gram, and fats - 9 calories per gram.
Step 5 - Test, Test, Test
Download any free app for tracking macros and calories and start experimenting. There is no magic formula, no magic macro distribution. Only you could tell what works best for you! Test, try, be curious about new foods and combinations!
Calculating macros is not a rocket science and definitely has some more details, but you need to start with the basics first and not overcomplicate things.
Choosing any number is not going to magically transform you in a short period of time. There is no one miraculous calculator, as well. Yes, you can start seeing amazing results from the beginning, but the trick is to start with some numbers, try them out for a couple of weeks, and adjust them according to your personal preference and to your lifestyle.
Make those numbers work for you and not the other way around!
Start macro-mathing and see your body finally change, girl!