This article has been Fact-Checked by Kendall Kennedy MS, RD, RYT
All this talk about calories counting can get confusing. Once you know how much you’re eating how many calories are needed for weight loss?
People gain weight because they consume more energy in the form of calories than they burn. The amount of excess energy gets stored on your body to be used for later. In prehistoric times this was pretty useful, you couldn’t always find calorie rich food. It could help you go without food for a while.
However, these days, where calorie dense food is so readily availble, it is not so useful anymore.
Too much body fat increases your chances of getting all kinds of diseases and other negative health consequences.
So then how eating how many calories is needed for weight loss?
Weight loss vs fat loss
One thing every person trying to “lose weight” has to be aware of is that weight loss is not fat loss.
The difference in the number on the scale isn’t always how much fat you’ve lost or gained.
There is a pretty easy experiment you can do to show this.
Step on the scale. Weigh yourself. Note down the number and drink a litre of water. Then step on the scale again and notice the difference.
Even though there were no calories in the water, you’ve gained 1kg (+-2 pounds).
When you’re trying to “lose weight” you most likely mean lose fat. The problem is that measuring your fat loss progress isn’t always as easy.
That’s why it’s okay to use weight as a measurement if you don’t pay too much attention to every single measurement. Try to look at trends to see whether you are still making progress.
How many calories do you need to burn to lose weight
Your body uses the energy from the food you eat first. Then if it still needs more energy, it starts to convert body fat into usable energy. This means you want to be in a calorie deficit in one way or another.
So, you have to know two things. How many calories are you absorbing each day and how many calories are you using each day.
This sounds pretty easy at first but it’s pretty hard to know these numbers down to the calorie.
For example how many calories you use each day depends on things like age, gender, lean muscle mass, mass in general, activity levels,…
There are formulas to get an estimate of how many calories you use each day but keep in mind that this number is just that. An estimate.
Calculating approximately how many calories per day you need
The following formula is called the “Mifflin – St Jeor Formula”.
It’s different for men and women:
Metric: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) + 5
Imperial: (4.536 × weight in pounds) + (15.88 × height in inches) − (5 × age) + 5
Metric: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) – 161
Imperial: (4.536 × weight in pounds) + (15.88 × height in inches) − (5 × age) − 161
Again, keep in mind that this is an estimate. The only way to know for sure is doing lab tests.
Calories needed per day for weight loss
Then the next step is to decide how much of a calorie deficit you want each day.
Keep in mind that too much of a calorie deficit isn’t a good thing. A healthy weight loss rate for most people is a calorie deficit of 500 calories or less. So you take the number calculated above and subtract a max of 500.
Or you can also increase the amount of calories you use each day. One of the most popular ways to do this is by exercising.
One pound of body fat is about 3500 calories (1 kg +-8000 calories). So if you be in a calorie deficit of 500 each day you would lose a pound of body fat per week.