I wrote at-length about the pros, cons and science of flexible dieting here. In this article I wanted to cut off any of the back story about flexible dieting and just stick to how to calculate your macros and track them accurately.
- Calculate your TDEE
- Eat 1 g of protein per pound of body weight (Protein: 1 g = 4 calories)
- Make 25 – 35% of your TDEE come from Fats (Fats: 1 g = 9 calories)
- Fill the rest of your TDEE with carbs (Carbs: 1 g = 4 calories)
- When adjusting macros for weight loss/gain keep fat and protein constant. Change only carbs.
Assessing Your Needs: Total Daily Energy Expenditure (TDEE)
Total Daily Energy Expenditure (TDEE) is the amount of calories you need in a typical day to keep your body composition the same. Less calories than your TDEE and you’ll lose weight, more calories than your TDEE and you’ll gain weight. There are loads of TDEE calculators online, here are a few that I trust.
- Muscle for Life: http://www.muscleforlife.com/tdee-calculator/
- IIFYM: http://www.iifym.com/tdee-calculator/
- TDEE Calculator: https://tdeecalculator.net
Keep in mind that these calculators are not going to have absolute precision. They can work as a great estimation but in the end you’re going to have to tinker to find your precise TDEE. I recommend spending at least 6 weeks trying to dial in your TDEE from one of these estimations by feel before lowering or increasing.
In each section I’m going to have an example of someone calculating their macronutrients, let’s call him Ted.
Ted uses all 3 calculators above and finds that his average TDEE is 2400 calories per day.
Calculating the Macronutrient Spread
(4 Calories per gram)
For the sake of this article I’m going to assume you exercise regularly (or want to) and thus should be on a high(er) protein diet to facilitate recovery. For this I recommend anywhere from 0.8 grams to 1.2 grams of protein per pound of body weight. The most commonly used is 1 gram per pound. For someone that is extremely lean 1.2 grams is better and for someone that is overweight 0.8 grams is better.
Ted has started weightlifting and is mildly overweight. Ted sets his protein to 1 gram per pound of body weight. He must eat 160 g of protein a day. That’s 640 calories out of his available 2400, leaving 1760 for carbs and fats.
(9 Calories per gram)
Fats are necessary for a whole host of bodily functions, especially hormonal function so don’t cut out the fats entirely thinking that’s the way to get slim. For most athletes 25-35% of calories coming from fat is optimal unless you are trying to become a fat adapted athlete in which case this won’t be nearly enough.
Ted wants to be able to have a lot of carbs in his diet so he chooses to keep his fat restricted to 25% of his TDEE. This would mean that Ted needs 600 calories from Fat and since Fat has 9 calories per gram he needs to eat approximately 67 g of fat a day. This leaves 1160 calories for carbs.
Note: The amount of fat is calculated from his TDEE not his total amount of calories, this means that you should keep fat constant whether you’re restricting calories or increasing them.
(4 Calories per Gram)
Carbs, that delicious energy source and the weakness in many diets. Flexible dieting actually allows us to indulge in carbs within reason. While it is possible to get all of your carbs from sugar and pizza, it’s not advisable. To calculate carbs you simply take your remaining calories after protein and fat, divide by 4 and voila! You have your amount for carbs.
Ted has 1160 calories left after proteins and fats. 1160 calories = 290 carbs! So Ted should eat, everyday:
- 160 g Protein
- 67 g Fat
- 290 g Carbs
If Ted sticks to these numbers he will be able to maintain his current body composition.
Macros to Lose/Gain Weight
Let’s look at the example of Ted again:
Ted was slightly overweight, his TDEE was 2400 and his maintenance macros were:
- 160 g Protein
- 67 g Fat
- 290 g Carbs
But since Ted is overweight let’s say he wants to lose some weight. Well the most common method is to cut calories by 10 – 30% (over 30% is a bit too aggressive for most people). The idea is to cut down the total calories but keep the protein and fat the same, this means that only the amount of carbs ingested will change.
Ted decides to cut his calories down by 15% so that his total caloric intake is now 2040 calories. Keeping the proteins and fats the same he now calculates the new amount of carbs:
- Protein = 160 g (640 calories)
- Fat = 67 g (600 calories)
- Carbs = 2040 – 1240 (calories from proteins and fats) = 800 calories = 200 carbs!
Notes: Cutting calories by percentages is a strong strategy in the long term. Many people try to cut 500 calories a day to lose a pound a week, ignoring how thermogenesis reacts to this, this isn’t a very great plan. For a 240 lb man cutting 500 calories a day might just be a 15% reduction and feels pretty easy while a 140 lb woman it might be a 35% reduction and could be borderline starvation.
For most purposes gaining weight, or “bulking,” is simply just the reverse process of cutting down calories. We set the calories into a 10-20% surplus and recalculate our carb intake just as we did before. Additionally some people increase their protein intake as well.
How am I supposed to count the macros in all the food I eat?
Get a macro tracking app
The most popular app for this purpose is MyFitnessPal: it has a great library of foods and it’s only limitation is that the free version only lets you set general percentages for you macros. Luckily it’s not too hard to get your numbers in the general ball park.
Invest in a quality food scale
Before you even try to say it:
“You suck at eyeballing the amount of food your eating!”
We all do. Invest in a quality scale and weigh out as much food as you can. It can be mundane and ridiculous feeling to start this habit but once it becomes second nature you begin to have a better understanding of what you eat everyday.
Keep up with your efforts to track your food. We all have days where we go over, sometimes that last slice of pizza was too tempting. Don’t let reasons like this become sources of self-loathing that drive you to quit, be consistent and keep logging what you eat. It’s what you do 90% of the time that makes the difference, not that 10% where you’re not perfect.