How to Know How Many Calories You Are Actually Burning
You can enter your stats into online calculators, tweak Fitbit settings, and carefully track every calorie burned, but no math can tell you how many calories your body actually burns in a day. To get a real answer, you need to experiment a bit.
Calculators can give you a starting point
If you want an approximate number of calories a person your height should burn, there are formulas that might come close. The calculator mentioned here uses the Mifflin-St calculator . Geor’s Equation (or two other options of your choice) to estimate your BMR or basal metabolic rate. A related statistic is your RMR, or resting metabolic rate. Both are designed to keep track of the calories your body burns to stay alive.
However, we burn more – you also need calories to get up and walk, exercise and digest food. The total number of calories a person burns in a day is their TDEE, or total daily energy expenditure. Calculators can guess this number. For example, the associated calculator says my BMR is likely to be 1,309 calories per day, and for my activity level it estimates the TDEE to be 2029. Experience tells me this is pretty close – good job calculator!
To get an accurate estimate, you need to track your weight.
All different. Maybe I fidget more than you; perhaps your gut bacteria are better at digesting food than mine. If you want to track your calories to gain, lose, or maintain your weight, you need to track your calorie intake and your weight.
One way to do this is by using the famous TDEE spreadsheet on Reddit . Each day, you enter your weight in the morning and the number of calories you ate during the day. (You will need to carefully monitor your diet , so this method is not for everyone.) The magic is simple: the table shows the average weight per week and the average number of calories per week. If your weight increases, you know that you have eaten more than your TDEE. If you are losing weight, you will eat less.
You can do a similar calculation on the back of any envelope. Basically, if your weight remains stable, then whatever number of calories you consume is your TDEE. This happens to most of us most of the time!
Even this method is not entirely accurate.
Unfortunately, humans are not machines. We have lives and we change our activities and food all the time. If you lose weight, your body will start saving some calories . On the other hand, the calculator doesn’t take into account how your activity is changing. If you change your exercise regimen, get sick, or go to work more often than before, your energy expenditure will increase.
The TDEE tracker can help you figure out how your spending has changed over the past few weeks, but it cannot provide daily guidance on how many calories you should eat or what to expect on the scale tomorrow. In any case, our weight fluctuates from day to day. So track your TDEE if you want the full picture, but nothing can give you perfect accuracy.