Have you ever wondered exactly how much you should be eating? Why you aren’t losing weight? Why you can’t seem to gain weight? Why you can eat the same amount as someone else but you gain weight and they never seem to?

We’ve all had these questions, and they can be answered by a four simple steps:

Calories are energy. BMR will tell you how much energy your body needs to take in.

BMR stands for basal metabolic rate. It is how many calories your body burns at rest. You can calculate this number by using your height, weight, age and activity level. It is easiest to use an online BMR calculator where you can simply input this information. However, if you would like to do it by hand, I recommend the Mifflin-St. Jeor equation:

BMR(kcal / day) = 10 * weight (kg) + 6.25 * height (cm) – 5 * age (y) + s (kcal / day) , where s is +5 for males and -161 for females.

2. Multiply by your activity level

Now that you have your BMR, you know how many calories your body is burning if you didn’t do any exercise or movement at all. Now, most people move at least a little bit every day. So you need to multiply by your activity level.

If you do very little exercise, you are considered sedentary, you will multiply your BMR by 1.2

If you do some exercise, 1-3 times a week, you will multiply your BMR by 1.4

If you exercise moderately, or 4-5 times a week, you will multiply your BMR by 1.5

If you do intense exercise 3-4 times a week, or daily exercise, you will multiply your BMR by 1.6

If you do very intense physical exercise daily, multiply your BMR by 1.7

For example, let’s say you calculated your BMR as 1,441 calories and you do moderate exercise, you would multiply by 1.5 and your daily calories burned would be 2,161 calories.

3. Determine how many calories you are eating

Calculating calories is very tedious and can be annoying at first. I would recommend counting your calories using myfitnesspal or another tracking app for at least a week just to get an idea of how many calories your common foods have.

From this you’ll be able to see if you have been eating the right amount. Maybe you’ll find that the snack you eat every day is adding an extra 400 calories to your total and this is why you aren’t losing weight.

4. Learn to balance your meals

Now you can take what you’ve learned and apply it to meals you already eat. Play with serving sizes to get a more customized meal.

This is easiest if you divide your daily calorie limit by 3. For example, if your daily calories burned is 2,161 aim to eat around 720 calories per meal.

Obviously it isn’t essential that you count and monitor every calorie you eat. Simply use this as a guide to help you eat the right sized servings for your body. You never have to be perfect and you can always have cheat meals and cheat days.

Remember that there are no rules here. This is just to unveil any mysteries surrounding your diet and how much energy your body truly needs.