As a personal trainer, I’ve lost count of how many times this question has been put to me: how many calories should I be taking in for my body?
Now this is a really valid question if you are keen to lose or maintain weight, because what you eat, in conjunction to what exercise you do determines how many calories you need to consume each day.
In determining exactly how many calories you need to consume each day, you need to determine how many calories each day your body will actually use. Think of it as income to expenditure. Your food or calories are income and the spending of calories through exercise is the expenditure. The first step in calculating the calories you must consume each day, is to determine your Basil Metabolic Rate or BMR.
Now, rather than go into great detail and outline the formulas for calculating your BMR, it’s easier for you to just enter your weight and height details into the BMR calculator . I’m going to ask you to go and get your BMR now, so please google BMR calculator in another screen and get your BMR number.
Okay, you’ve got your BMR now? That’s great! Determining how many calories per day your body needs to consume is easy.
The amount of calories you must consume per day – referred to as Total Daily Energy Expenditure or TDEE – is determined by the amount of exercise you engage in each day. TDEE tells us how many calories we need to maintain our weight.
Total Daily Energy Expenditure for somebody who does very little is calculated by your BMR x 1.2. If you do very light activity 1-3 days per week, your Total Daily Energy Expenditure is your BMR x 1.375. If you engage in moderate activity, exercise or sport 3-5 days per week, your TDEE is BMR x 1.55. If you do high physical activity, sport or exercise 6-7 days per week, your TDEE is BMR x 1.725 and if you are involved in very heavy activity – a physical job, or you do a lot of sport or exercise twice a day, everyday, your total calorie intake per day is calculated by BMR x 1.9.
Now that you know how to calculate your daily calorie needs for maintaining weight, how do you calculate daily calories needed to lose weight?
You need to subtract from your Total Daily Energy Expenditure figure to lose weight. To determine how much to subtract, you need to know how calories relate to weight. And that’s why I need to mention the following:
1 lb (0.45kg) equates to 3500 calories
1.5 lb (0.68kg) equates to 5250 calories
2 lbs (0.91kg) equates to 7000 calories
Say for example, your BMR is 1800 calories and you do moderate exercise. Your TDEE is:
1800 x 1.55
So your TDEE is 2700 calories per day to maintain your current weight. Multiply 2700 x 7 and your weekly calorie intake to maintain your weight is 18,900 calories.
So, if you want to lose 2lbs per week, here’s how you calculate the calories you need to consume per day:
18,900 – 7000 = 11,900/week
11,900/7 days = 1700 calories/day
You need to consume 1700 calories per day to lose 2lbs per week.
It’s important to never exceed weight loss of 2lbs per week, because to lose more than this will burn muscle, overtraining, or burnout which is unhealthy. You need muscle to help you burn fat, so keep your weight loss to a healthy level.
So now you know how to determine the calories you need every day.