When it comes to losing weight, we often talk about shedding calories, but it’s essential to have a fair understanding of what calories are and how it affects your fitness goals. Having some knowledge about your daily calorie requirements helps you be on track to lose weight. Here, we explain how to calculate the exact number of calories to be burned for shedding one kilogram of weight.
What are calories?
Calories are a measure of units of energy as per the international system of units. The number of calories in a food is a measure of how much energy that food possesses. Your total daily energy expenditure (TDEE), the number of calories you burn each day plays a vital role in maintaining your weight.
Exercise, Diet & Calories
Exercise can regulate energy balance by affecting the intake and expenditure of calories. The more intense the exercise, the more calories you will burn. For instance, when researchers compared runners and walkers within a period of six years, they found that calories burned through running led to 90 percent more weight loss than calories burned through walking [2]. A study states that low-calorie diets (one that restricts your intake to 1,200 to 1,600 calories per day for men, and 1,000 to 1,200 calories per day for women) are a safe strategy for weight loss [3].
Calorie Requirement For Weight Loss
Your BMR (basal metabolic rate) is responsible for burning 60 to 70 percent of the total calories you burn in a day. Calculating it is the first step to find out the calories for losing weight. Listed below are two formulas for calculating the BMR :
- Mifflin-St Jeor Formula
Mifflin-St Jeor formula is believed to give the most accurate results [4]. Here is how to estimate your Basal Metabolic Rate using the Mifflin-St Jeor formula:
Formula for estimating BMR in women:
(9.99 x bodyweight (in kilograms)) + (6.25 x height (in centimeters)) – (4.92 x age) – 161
Formula for estimating BMR in men:
(9.99 x bodyweight (in kilograms) + (6.25 x height (in centimeters)) – (4.92 x age) + 5
- Harris-Benedict formula for estimating BMR in women:
It is one of the oldest and most commonly used formulas for calculating BMR.
Formula for estimating BMR in women:
BMR = 655 + (9.6 × weight in kg) + (1.8 × height in cm) – (4.7 × age in years)
Formula for estimating BMR in men:
BMR = 66 + (13.7 × weight in kg) + (5 × height in cm) – (6.8 × age in years)
After you estimate your BMR using the Harris-Benedict formula, the next step is to include the number of calories you burn during daily activities based on your lifestyle:
Sedentary: If you do minimal or no exercise at all, multiply your BMR by 1.2.
Lightly active: If you exercise lightly for one or three days a week, multiply your BMR by 1.375.
Moderately active: If you exercise moderately for three to five days a week, multiply your BMR by 1.55.
Very active: If you perform hard workouts almost six to seven days a week, multiply your BMR by 1.725.
Extra active: If you engage in a very hard workout for six to seven days a week or have a physical job, multiply your BMR by 1.9.
The final number will be the approximate calories you require daily for maintaining your weight.
According to a study [5], a pound of fat is around 3,500 calories, therefore to lose 1 kg per week, you need to cut 7,700 calories from your diet each week or 1,100 each day. However, this number may vary depending on various factors such as gender, age, height, body weight, metabolic health, etc. Having a better understanding of calorie calculation can help you determine the best activities, both exercise, and non-exercise for meeting your fitness goals.
References:
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3630467/
- https://www.ncbi.nlm.nih.gov/pubmed/23190592
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1319349/
- https://www.ncbi.nlm.nih.gov/pubmed/15883556
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2376744/
