How to Calculate the Amount of KCAL for a Weight Loss Diet for Women

How many calories should a woman consume daily to lose weight?

As you might expect, there is no single answer to this question. The number of calories a woman should eat to lose weight depends on several factors, such as her current weight, height, age, and level of physical activity, among others.

Would you like to understand how these characteristics influence a woman's caloric needs? Next, we will explain it to you:

How many calories does a woman need per day?

Before delving into the diet to lose weight, first, we will explain in the simplest way possible how we use the calories we get from food on a daily basis. To do this, we will decompose the total energy expenditure (GET) into its three basic components:

• Basal metabolism
• Thermogenic activity of foods
• Physical activity

It is important to note that if a person is sick, pregnant or growing, their energy expenditure will be "extra" due to these circumstances. We will focus on a healthy adult woman with the goal of losing weight.

basal metabolism

To lose weight, it is necessary to achieve a negative energy balance, that is, expend more calories than you consume. Of this daily energy expenditure, basal metabolism represents between 60 and 70% of calorie consumption, as indicated in an article in the Journal of the Faculty of Medicine of the National University of Colombia¹.

More than half of the calories we get from food are used for vital functions, such as breathing, heartbeat, and maintaining body temperature, among others.

This is the basal metabolism, and any diet must provide enough energy (calories) to cover it, otherwise you could experience dizziness, fainting and, in the long term, you could experience the dreaded rebound effect, regaining the lost weight quickly.

The thermogenic activity of foods

Did you know that you burn calories by chewing, digesting, absorbing and using nutrients? This is known as the thermogenic activity of food and can represent 10% of daily expenditure. However, consuming more fiber and protein can increase this value. That is why protein and fiber intake is so relevant.

Physical activity, the most modifiable factor

You burn calories not only when you run or train at the gym, but also when you walk to work, climb stairs, and move around your house while doing your daily activities. Every move counts. Calorie expenditure due to physical activity in a moderately active person represents between 20 and 30% of the GET.

How many calories should a woman consume daily to lose weight?

As we mentioned above, a weight loss diet for a woman must provide at least the calories necessary to satisfy basal metabolism. There is an old equation, dating back to 1919, that is still useful for estimating this number of calories, as explained in a review from Tel Aviv University².

To determine how many calories a woman should consume to lose weight, the equation is calculated as follows:

GEB (for women) = 655.1 + (9,563 x Weight in Kg) + (1.85 x Height in cm) - (4,676 x Age in years)

As an example, if a woman weighs 70 kg, is 165 cm (1.65 m) tall and is 30 years old, her basal energy expenditure would be:

GEB = 655.1 + (9,563 x 70) + (1.85 x 165) - (4,676 x 30)

GEB = 1489.48 calories (or kilocalories), which are rounded to 1500.

For your diet to be healthy and avoid the rebound effect, you will need to provide at least 1,500 calories a day.

A simple formula to calculate calories

If you want an even simpler equation to determine how many calories you should consume to lose weight or maintain your weight, multiply your current weight (in the example above, 70 kilograms) by 30 or a smaller value, depending on your goals.

If you multiply your weight by 30, to maintain it, you will get a result of 2100 calories.

On the other hand, if your goal is to lose weight, you should multiply your weight by a value less than 30, but not less than 20, since a diet with fewer calories could be too restrictive.

As an example, if you weigh 70 kg and multiply by 25, you would get 1750 calories. With this daily calorie intake, you would lose weight and, at the same time, cover your basal metabolism. However, if you multiplied by 20, the diet would contain 1,400 calories per day, slightly below the basal metabolism.