How Many Calories per Day Should You Eat?

The number of calories per day that you should eat varies according to gender, age, height, and weight. Keep reading to learn more.
How Many Calories per Day Should You Eat?

Last update: 19 June, 2023

Calories are the measure of energy in nutritional terms. This energy is what maintains body temperature and vital functions such as circulation, respiration, and digestion. With this in mind, many ask how many calories per day should you eat.

In order for the body to function properly and maintain stability, energy expenditure shouldn’t be less than consumption. The precise number of calories per day that individuals should eat depends on several factors: Gender, age, weight, height, and lifestyle.

Knowing how many calories to eat can help you maintain or lose weight. Hence, many diets to lose weight are so strict in their counting. To avoid an imbalance of energy in the body, it’s best to consult a nutritionist.

How to calculate calories?

As we mentioned, identifying the right number of calories per day depends on different factors. There are pre-established calculations that indicate the amount that people of a certain age or sex should consume, considering the basal metabolism.

Basal metabolism refers to the amount of energy required by the body to perform basic functions while at rest. But considering that everyone has different lifestyles, this calculation isn’t entirely accurate. Let’s look at it this way: Two people of the same sex and age can have different body compositions.

However, we found other types of formulas that can provide a more adjusted result for each person. These are some of the options.

A woman using a cell phone app to count calories..
Calorie counting is a practice that can help shape a diet.

The Harris-Benedict formula

The Harris-Benedict formula is a bit complex, but it makes it possible to identify basal metabolic rate (MBR) by considering variables such as sex, age, weight, and height. Some studies indicate that this is one of the most accurate calorie calculation formulas.

In order to apply it, you must identify the physical activity factor according to these standards:

  • 1.2 if you are sedentary or perform physical activities such as housework.
  • 1.375 if you do physical activity between 1 and 3 times a week.
  • 1.55 if you do physical activity 3 to 5 times a week.
  • 1.725 if your activity is intense and goes from 6 to 7 times a week.
  • 1.9 if you are a professional athlete and spend more than 4 hours a day training.

With this clear index, you can apply the following formula:

  • Women: [655 + (9.6 × weight in kg) ] + [ (1.8 × height in cm) – (4.7 × age)] × Activity factor
  • Men: [66 + (13.7 × weight in kg) ] + [ (5 × height in cm) – (6.8 × age)] × Activity factor

A woman who weighs 78 kilos, is 163 centimeters tall, is 28 years old, and leads a sedentary life would eat 1877 calories per day to maintain her weight.

Example: [655 + (9.6 × 78 kg) ] + [ (1.8 × 163 cm) – (4.7 × 28)] × 1.2 = 1877 calories

Mifflin’s formula

Although the Harris-Benedict formula turns out to be very accurate, in cases of excess weight or obesity, it can stimulate more calorie consumption. Therefore, the Mifflin formula is preferred there:

  • Women: 10 x weight in kilos + 6.25 x height in centimeters – 5 x age in years – 161
  • Men: 10 x weight in kilos + 6.25 x height in centimeters – 5 x age in years + 5

To establish the difference, we’ll apply Mifflin’s formula to the same adult woman in the previous example:

Example: 10 x 78 kilos + 6.25 x 163 centimeters – 5 x 28 years + 161 = 1497.75

This means that if this woman is overweight, she should consume a total of 1,497 calories, that is, 380 fewer than those calculated with the Harris-Benedict formula.

Simple calculation by sex

Another mathematical operation that can determine in a very simple, although not completely exact way, the calories per day that you should consume if you’re a man or a woman is the following:

  • Adult men: Weight in kilos x 25
  • Adult women: Weight in kilos x 23

To identify the accuracy of this measurement, we’ll apply this calculation to the same 78-kilogram adult woman that we measured with the previous formulas:

Example: 78 kilos x 23 = 1794 calories

We found the difference to the Harris-Benedict formula to be 83 calories. Although it seems minor, it can be significant depending on the physical activity that the woman performs. Regarding the result of the Mifflin formula, the difference is 297 calories.

The calculation of calories in children and adolescents

Although in these age groups, the calculation depends on age, height, and activity level, it’s not advisable to be strict with the number of calories consumed per day. This is because they’re populations that usually do a lot of physical activity.

According to the United States Office of Disease Prevention and Health Promotion, an infant between the ages of 2 and 5 who engages in moderate physical activity should consume between 1,200 and 1,400 calories per day, while children between the ages of 6 and 12 with the same activity should consume a daily total of between 1600 and 2200.

Calories per day for older adults

Measuring the exact number of calories older adults should consume is more complex. Many factors come into play here, especially because physical activity tends to decrease quite a bit.

However, it’s found that adult men over the age of 60 who engage in moderate physical activity should ingest approximately 2,400 to 2,200 calories. It’s worth mentioning that at an older age, it’s better to reduce intake. Women of the same age and activity level should consume about 1,800 calories per day.

A man counts his calorie intake.
The different moments of life vary the energy needs, and that’s something that must be considered in a nutritional plan.

How to consume fewer calories?

When you want to consume fewer calories to lose weight or gain wellness, it’s important to ensure adequate nutrient intake. Sometimes, the fight against calories leads us to expel from our daily diet foods that provide vital nutrients, vitamins, and minerals.

Therefore, below we’ll tell you what foods you could exclude from your diet without affecting nutritional well-being :

  • Sugary soft drinks, juices, and nectars: Studies have shown that these types of drinks are related to the increased risk of obesity due to their high concentration of sugar.
  • Refined carbohydrates: These foods are high in calories. Therefore, reducing their consumption has been shown to help in the weight loss process, as it reduces the feeling of hunger.
  • Sausages: Sausages such as bologna and chorizos, among others, not only provide many calories to the diet, but they’re usually fried, adding unhealthy fats to the diet.
  • Fast food: Hamburgers, hot dogs, and French fries provide up to 300 calories in a single meal. So they should be avoided if you’re overweight.
  • Industrial snacks: These are usually favorites when it comes to satisfying hunger or cravings between meals, but they also harm low-calorie diets. So, goodbye to potato chips.

Don’t obsess over the number of calories per day that you should consume

Although it’s healthy to know how many calories per day your body needs, it’s recommended that this process be accompanied by a health professional. In this way, a specific diet will be obtained that meets the needs of each person and avoids developing obsessions with the calorie count.

In cases where you want to lose weight, doing more physical activity is ideal. With this, not only do you benefit the overall health of the body, but you can also include caloric foods in your diet, as you’ll burn off the calories through exercise.




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