A calorie is a unit of measure for the energy value of foods. We are talking about the amount of thermal energy that the body produces when assimilating food. For its designation, it traditionally uses kilocalories (kcal).
How do scientists calculate the energy value of certain foods? They burn them in special devices and measure the heat generated during this process. Sealed chambers also allow measuring the heat emitted by a person, due to which it is possible to judge the physiological energy value of food.
There are different approaches to weight control. One of the most effective is calorie counting. In short: to lose weight, you need to expend more energy than you consume. But how do you know for sure how many calories you are getting per day and how many are you “burning”? For this, calculation systems have been developed. To calculate the calorie content of the diet, you need to know the weight of each portion, keep a food diary. This may seem daunting and cumbersome if you are not used to it, but you will quickly get used to it. Moreover, unique applications for a smartphone make the task easier.
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Daily calorie intake for an adult
How many calories you need to consume per day depends on many factors, including age, weight, height, gender, health, and lifestyle. Doctors assess the recommended calorie intake differently. The British National Health Service calls these numbers:
- 2,500 kilocalories – the average rate for men per day;
- 2,000 calories are the average for women.
One kilocalorie contains a thousand calories. The numbers shown represent the number of calories needed to maintain stable body weight. These numbers should not guide you if you plan to lose weight, but it is essential to take them into account to understand your own physiological needs clearly. However, there are other recommendations; for example, American researchers suggest a different norm:
- 2,700 kcal per day – for men;
- 2,200 kcal – for women.
The UN claims that the average person needs a minimum of 1,800 kcal per day. According to UN experts, please note that this is the minimum, not the optimal amount of calories. At the same time, the British National Health Service recommends paying attention to the calorie content of food and its quality and variety, not to neglect physical activity. Israeli scientists insist that a hearty breakfast of up to 700 calories helps maintain healthy body weight and reduces the risk of developing diabetes.
However, all these figures are approximate. And to calculate how many calories you need per day, you will have to use unique formulas.
How to calculate your daily calorie intake
There are several approaches to calculating the optimal calorie intake. Doctors often recommend the so-called Harris-Benedict equation, which allows you to estimate the basal metabolic rate or BMR and the need for energy. Using this formula, you can calculate how many calories you need to keep your weight stable:
- for adult men: 66.5 + (13.75 × weight in kg) + (5.003 × height in cm) – (6.755 × age);
- for adult women: 55.1 + (9.563 × weight in kg) + (1.850 × height in cm) – (4.676 × age).
The resulting figure is the number of calories you burn per day at rest. The formula does not consider physical activity, which must be considered, and the ratio of fat to muscle tissue. Whereas with the same weight, a person with developed muscles will consume more energy than someone who has a significant percentage of their importance in adipose tissue.
To take into account the level of physical activity, the figure obtained in the calculations must be multiplied by an exceptional coefficient:
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- 1.2 – sedentary lifestyle;
- 1,375 – light physical exercise 1-3 times a week;
- 1.55 – moderate loads 1-3 times a week;
- 1,725 - intensive loads 6-7 times a week;
- 1.9 – hard training twice a day.
After multiplying BMR by a coefficient, we get the approximate number of calories you should consume per day to maintain body weight unchanged. Keep in mind that going too far in reducing calorie intake is dangerous to health since the brain consumes about 20% of all energy. Many calories are also required to maintain the work of internal organs and systems.
However, there is another approach to calorie intake. Some doctors suggest the following average daily energy requirements:
- For women leading a sedentary lifestyle: 2000 kcal – at the age of 19-25, 1800 kcal – 26-50 years, 1600 kcal – over 50 years old.
- For ladies who perform light physical exercises up to three times a week: 2200 kcal – at the age of 19-50 years, 1800 kcal – over 50 years old.
- For women leading an active lifestyle who regularly go in for sports: 2400 kcal – at the age of 19-25, 2200 kcal – from 25 to 50 years, 1800 kcal – over 50 years old.
- For men leading a sedentary lifestyle: 2400 kcal – aged 19-30 years, 2200 kcal – from 31 to 50 years old, 2000 kcal – over fifty.
- With moderate physical exertion: 2600 kcal – at the age from 19 to 30 years old, 2400 kcal – from 31 to 50 years old, 2200 – over 51 years old.
- With an active lifestyle: 3000 kcal – from 19 to 30 years old, 2800 kcal – from 31 to 50 years old, 2400 kcal – over 51 years old.
Calorie Calculation for Weight Loss
To lose weight, you need to eat fewer calories than you burn. It is not difficult to understand precisely how many calories should be in the daily diet: you need to reduce the rate of the energy value of food. If you exercise regularly, go in for sports at least several times a week, it is enough to reduce the calorie intake by 10%. If you have calculated that your physiological norm, taking into account your lifestyle, is 1800 calories, then for weight loss, you need to cut your daily diet to 1680 kcal.
If you lead a sedentary lifestyle and physical activity is an exception to the rule, you will have to take 20% of calories from the daily menu. Then, with a physiological norm of 1800 kcal, you will need to eat only 1440 kcal per day to lose weight.
A drastic reduction in more than 20% diet poses health risks. But if you are obese and tend to overeat, your doctor may recommend cutting your diet by 40%. But not from the physiological norm, but from the amount of calories you are used to eating every day.
An easy way to balance weight loss meals
Calculation of calories requires habit and knowledge of the energy value of different foods. It is essential not only to adhere to the daily requirement but also not to forget about the quality of the products because 500 kcal of fresh vegetables is healthier than 500 kcal of sweets and fast food. You do not need to weigh the food yourself and make a menu for the week: we offer ready-made balanced meals for the amount of kcal you need. It is healthy and tasty, which means that there will be no temptation to eat too high-calorie foods.
