How many calories does a person need per day: calculating the daily requirement

To feel well and maintain vital functions, a person needs a source of energy. You can get it from various foods that contain useful substances - fats, proteins and carbohydrates. The indicators of these components affect the calorie content of food. To calculate how many calories a person needs per day, you need to know your activity level, that is, energy expenditure.

Basics of Dietetics

Dietetics is the science of proper nutrition. The essence of energy balance is as follows:

1. The intake of food into the body must be equal to its consumption.
2. Food must contain carbohydrates, proteins and fats in the prescribed proportions.
3. It is imperative to have vitamins and microelements in your daily diet.

If a person does not receive enough natural active substances, he begins to develop various diseases (hypertension, obesity, diabetes and others), which leads to a decrease in average life expectancy.

Balanced diet

To know how many calories you can consume per day, you need to know your energy expenditure (metabolic rate). The general metabolism in a person depends on the main and additional ones.

Basic metabolism is the number of calories the body expends to perform all important functions. How many calories a person normally needs per day depends on the main metabolism and the following factors:

• floor;
• weight;
• height;
• body constitution;
• level of hormone production.

Accordingly, the calorie intake per day depends on the listed criteria. For example, in men, chemical processes in the body occur faster than in women. Young people spend more energy than older people. The average daily metabolism in the adult population is 25 kcal per kilogram of weight.

How much protein should a person consume per day to be healthy? Athletes and active young people should consume 1.5-2.5 grams of protein per 1 kg of body weight per day. A person weighing 80 kg can eat 200 grams of protein daily. People with moderate activity can consume up to 1.5 grams per 1 kg of body weight. If you have a sedentary lifestyle, then it is enough to eat up to 1 gram per 1 kg per day.

Daily diet options with different calorie content

Weighing each product on a kitchen scale and then calculating the calorie content of what you eat is a troublesome task, which is why this method of losing weight is not suitable for many. But you can do it differently: make a table where you list the menu by day with a detailed indication of the weight of the dishes.

At 1800 kcal

In order to alleviate stress on the body, it is better to start with a relatively high-calorie menu. There is another important point: you must get used to fractional nutrition, that is, eat few foods, but at the same time eat more often. The break between meals should be 2–3 hours.

For 1200 kcal

When the body gets used to eating little, the amount of calories consumed must be gradually reduced. On average, adaptation lasts 7–14 days.

For 800 kcal

Not everyone reaches the level of consumption of 800 kcal per day; moreover, it is undesirable for the stronger sex to resort to a low-calorie minimum, but this diet is optimal for girls.

Where do calories come from?

As mentioned above, food contains carbohydrates, fats, proteins, vitamins, microelements and water. The last three components do not provide energy to the body. The calorie content of food is expressed in the energy value necessary to maintain life in the human body.

The human body consumes food to perform a variety of functions, such as heat generation, respiration, blood transport through cells, for rest and work, and sports. If a person consumes more than he expends, then some of the calories are stored as fat, and the person gets fat.

Online calorie calculator

The daily calorie intake calculator will help you find out:

• how many calories do you need to eat per day for your body to function normally?
• how many calories do you need to lose weight;
• How many calories does it take to gain weight?

To calculate calories for weight loss, you must indicate your height, weight, gender, age, and level of physical activity. You don’t need to do anything else, the online calculator will do everything itself.

Calculation of daily calorie intake can be done using two different methods: one of the most modern, according to the Mifflin-Saint-Geor formula, derived in 2005, and according to an older one, but still popular among nutritionists in our time, the Harris-Benedict formula, known since 1919.

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What happens when you don't have enough calories?

When calculating the daily norm, you need to take into account every little thing: putting butter in porridge or mayonnaise in a salad. An excess of calories, just like a deficiency, is fraught with consequences for the body. If there are few nutrients coming from food, the body begins to use energy from muscle tissue rather than from excess fat.

Lack of fats and carbohydrates in the diet can reduce basal metabolism. The body, maintaining a constant supply of sugar to the brain, uses up its own supply of glycogen, which is stored in the liver. Glycogen is gradually removed from muscle tissue, and as a result, a person begins to lose weight. If reserves are depleted, a person stops losing weight.

Fat tissue is not used to nourish the brain. During the period of weight loss, the body uses fat deposits as energy, but the decrease in these reserves is much less than the loss of muscle and bone tissue. If a person deprives himself of fatty foods during a diet, then weight loss occurs due to bone and muscle tissue. This is fraught with danger for the body, as it threatens exhaustion.

Women's and men's daily calorie intake

Fats, proteins, and carbohydrates are three key microelements that provide the body with the necessary energy and support biochemical processes.
The female body requires less daily caloric intake than the male body. This is due to the inherent genetic ability to quickly gain weight for full procreation.

The average kcal per day for a woman is about 2000 kcal. If it is necessary to lose weight, 500 kcal or 10-20% are subtracted from the calorie norms for different age groups of women with different activities and diets.

At the same time, the number of calories per day should be reduced gradually, otherwise a sharp reduction in the supply of substances necessary for the body can provoke disruptions in the menstrual cycle, a weakening of the immune system, a slowdown in metabolism, or problems with the functioning of the heart.

. Daily requirement for proteins, fats, carbohydrates and calories for working men and women

Notes: 1. The requirement of pregnant women (5-9 months of pregnancy) is on average 12.2 thousand kJ, protein - 100 g per day, including 60 g of animal origin. 2. The need of nursing mothers is on average 13.4 thousand kJ, protein - 112 g per day, including 67 g of animal origin.

In order to determine how many calories a man needs per day, it is necessary to take into account that they have an accelerated metabolism and are prone to rapid weight loss. Therefore, the diet for males should consist of a varied set of foods.

The average calorie intake per day for a man is 2400 kcal and can fluctuate due to age, exercise intensity, lifestyle and weight. To lose weight, men, like women, need to consume 10-20% fewer calories than required.

The daily requirement for calories, as well as carbohydrates, proteins, fats for working women and men is presented in the table:

Formula for calculating daily value

How many kilocalories does a person need? The norm is determined based on the following data:

• basal metabolism is the expenditure on the vital functions of the body: breathing, digesting food, supplying organs with blood, and so on;
• daily expenditure on physical labor.

The Muffin Jeora formula will help you calculate the number of calories per day:

• OM for women = 6.26*(height in cm) + 10*(weight in kg) - 5*(age in years) - 161;
• OM in men = 6.26*(height in cm) + 10*(weight in kg) - 5*(age in years) + 5, where (OM) is general metabolism.

Using this formula, you can calculate how many calories a person should consume per day to lose weight. To gain weight, a person needs to increase this indicator by 20%, to reduce body weight - reduce it by the same amount.

Ketch-McArdle formula

This method does not take into account body weight, number of years and growth rate when calculating. Only the individual body fat percentage is included in the expression. The error in calculations based on this coefficient is large.

However, accurate measurements of body fat along with applying the result of the Harris-Benedict formula in calculations will give an indicator with minimal error.

The Ketch-McArdle formula does not require complex calculations and looks like this:

• BM = 371 + 20.59 * a

The last variable refers to the percentage of body fat. It can be measured using special equipment found in hospitals and gyms.

This indicator can also be approximately calculated by dividing the weight in kilograms by the height in meters squared:

• body mass index (%fat) = weight (kg) / height (cm)2.

A data table for certain groups can predict how many kilocalories a person needs per day with an equally large error. However, multiplying the coefficient obtained from the Ketch-McArdle formula by the result of calculation by the Harris-Benedict method will increase the accuracy of the measurements.

For women with parameters of 50 kg, 165 cm and a diet of 1332 kcal, calculated using the previous formula, the basic metabolism will be equal to:

BM=1332*(371+21.61*(50/1.652)) =1021 kcal.

For men with a weight of 70 kg, a height of 170 cm and a daily requirement of 1703 kcal:

BM = 1703 * (371+21.61 * (70/1.702) = 1521 kcal.

This result is more accurate, however, body weight without fat, calculated using the formula, is significantly inferior in error to measurements using special equipment.

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Norm for women

Young women aged 18-30 spend an average of 2000 kcal. If a woman is actively involved in sports or works a lot, the daily norm increases.

The norm of kilocalories per day for a woman depends on the same parameters as for men:

1. Sedentary lifestyle or no physical activity – 1300-1500 kcal per day.
2. Low physical activity – 1500-1700 kcal.
3. Moderate activity – 1800-2000 kcal.
4. Heavy loads – 2000-2400 kcal.

These are approximate values. How many calories a woman needs to consume per day can be calculated using a formula that takes into account weight, height and index (physical activity value).

Harris-Benedict formula:

447.6 + 9.2 * weight in kg + 3.1 * height in cm – 4.3 * age.

The result obtained must be multiplied by the activity index.

For example: a 26-year-old girl, 163 cm tall and weighing 64 kg. Goes to the gym two to three times a week.

447.6 + 9.2 * 64 + 3.1 * 163 – 4.3 * 26 = 1430 kcal.

Let's multiply it by the activity index (1.375) and get the daily requirement of 1966 kcal.

Women over 50 need slightly fewer calories as their basal metabolism declines.

A woman during pregnancy and lactation needs more calories. But this does not mean that pregnant women should eat for two; in case of edema or excessive weight gain, they may prescribe a diet. With a normal initial weight before pregnancy, pregnant women should consume from 2500 to 3500 kcal per day.

WHO formula

The World Health Organization (WHO) calorie formula is based on the same principle as the Muffin-Geor method. However, here age is placed in ranges and for each of them an individual calculation is carried out using the physical activity coefficient (PFA).

How many kilocalories a person needs per day is determined using an additional table taking into account the degree of physical activity, where 1 is low, 1.3 is medium, 1.5 is high physical activity.

A man with parameters 27 years old, 70 kg and CFA - 1.3 according to the formula has a coefficient:

(0.063 * 70 + 2.895) * 240 * 1.3 = 2279 kcal.

Norm for men

A man's diet should be high enough in calories to maintain all functions in the body. The daily calorie intake per day for men with moderate activity is 2500-2800 calories. If there is no physical activity, energy is consumed in different ways.

How to calculate how many calories a man needs per day? You can use the following formula: OM for men = 6.25*(height in cm) + 10*(weight in kg) - 5*(age in years) + 5.

There is another formula for calculation: (13.4 * weight in kg + 88.37 + 4.8 * height in cm – 5.7 * age) * activity index.

The daily calorie intake per day for a man depends on his activity. The result must be multiplied by the index, which corresponds to the level of physical activity:

• sedentary work or no activity - 1.2;
• light physical labor – 1.4;
• moderate physical activity – 1.55;
• heavy physical work – 1.7;
• hard physical labor + active sports training – 1.9.

Here is an example of calculating the amount of kcal per day for men:

A man with a height of 181 cm weighs 88 kg, moderate activity. Substituting the values ​​into the formula, it is easy to calculate how many calories a man needs per day: 6.25*(height in cm) + 10*(weight in kg) - 5*(age in years) + 5 = 1781 kcal.

When asked how many calories a man needs to consume per day if he wants to lose weight, the answer is that he must reduce his diet by 20%.

How many calories should you eat per day?

To calculate your daily calorie intake, you need to understand where it comes from. Why is 1500 kcal per day enough for some people, while others need 2000?

Learn to count calories and lose weight wisely!

We are sharing with you one priceless secret - how simple and easy it is to count the calories in what you eat. After all, knowing the calorie content of our own dishes, we have every right not to deny ourselves anything!

Natalie Lissy

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The basis of the daily calorie intake is their number, which is spent on maintaining internal processes in the body. As you know, the body burns a certain amount of energy even at rest, for example, during sleep. After all, the activity of organs and systems does not stop for a minute; various processes are constantly occurring in each cell of the body.

Watch the story about what the Hollywood diet is and what is included in its diet:

The number of calories needed to maintain the body's vital functions is called the "basal metabolic rate" number. BOV is calculated using special formulas into which the following data is substituted: body weight in kg, height in cm and age in years (used as variables). The remaining numbers in the formulas are constant.

The formulas for men and women are different.

The Mifflin–San Jeor formula for calculating the BOV of women: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) – 161.

As a rule, the figure is from 1200 to 1500 for an adult woman.

The Mifflin–San Jeor formula for calculating the BOV of men: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) + 5.

It provides approximately 1600–1800 kcal as the body's basic requirement. If you eat fewer calories than your BER, your metabolism will slow down over time. Because of this, you may begin to gain weight “from the air,” as they say.

In order not to harm the body and not incur obesity, be sure to consume the number of calories required for BOV. You can add any number of calories to this number, depending on your goals.

Goals could be the following

: weight gain; weight loss; maintaining current weight.

1. Want to maintain weight

If you want to maintain your current body weight unchanged, multiply the BW number by one of the physical activity coefficients.

Multiply by 1.2 for minimal or no physical activity. At 1.375 – if you play sports 3 times a week. At 1.4625 – if you study 5 times a week. At 1.550 – sports 5 times a week and physical work. At 1.6375 – if you play sports every day. At 1.725 – if you exercise every day and have additional physical activity. 1.9 – if you regularly and for a long time play sports and do physical work.

Of course, you will get an approximate number, but you can use it as a guide and stick to it.

2. Want to lose weight

In order to lose weight, subtract 200–300 calories from the resulting number, depending on the pace at which you want to lose weight.

3. Want to get better

If you want to gain weight, then vice versa - add 200-300 calories.

Weight correction

Systematic consumption of calories less than the daily norm promotes weight loss and weight correction, especially if you combine a diet with sports activities. The daily calorie intake for a woman when losing weight is 80% of the usual per day.

The same indicator is used when losing weight, if you need to calculate the daily calorie intake for men. For harmless weight loss, nutritionists advise reducing the calorie content of food gradually. If the norm of kilocalories per day is 2000, then using 1600 kcal per day, you can achieve gradual weight loss.

The norm of kilocalories per day for men to maintain weight is 1800 kcal. It is not recommended to reduce this value below to avoid health problems. The daily calorie intake for weight loss depends on the individual intake of a particular person.

The required nutrients must be contained in the exact ratio:

• proteins – 30%;
• carbohydrates – 50%;
• fats – 20%.

With classic weight loss, all these components should be present in the diet of any person. The lack of one of these components will negate all efforts. You need to plan your daily diet taking into account physical activity, and then your body will delight you with beauty and grace for a long time!

Parameters influencing diet choice

The diet should be based on the characteristics of the body and the required amount of nutrients. To calculate how many calories you need per day, you should consider:

• daily activity level;
• age and gender, since men need to consume more calories than women;
• availability of training;
• body parameters, which include height and weight;
• usual diet.

You can calculate how many calories you need per day to lose weight yourself using formulas or using an online calculator. For example, nutritionist Lydia Ionova not only explains each step in the calorie counting formula, but also teaches how to build a food pyramid. And American doctor Holly Phillips is convinced that by finding out how many calories you need to consume per day, you can get rid of fatigue.

Thus, having the necessary calculations in hand and knowing how many calories you need to eat per day, you can adjust your diet and achieve the expected results faster.