Our body requires energy to carry out its daily functions. About 80 percent of this energy is used by the body for basal metabolic needs such as cellular respiration and blood circulation; and about 20 percent for brain metabolism.
In addition, consuming the right amount of calories can help you maintain your weight. Calculating the number of calories per kilogram is the best you can do, but this depends on a set of variables such as age, height, sex and level of activity, which will affect your caloric needs.
Some formulas can help estimate your needs. That is why they are used as a starting point to determine the number of calories per kilogram you should consume. Let’s see how you can estimate them.
Caloric needs per kilogram of body weight
The calorie needs per kilogram vary according to the level of activity. For example sedentary people usually need between 24 to 30 calories per kilogram, 28 to 34 calories per kilogram if they are moderately active, and 32 to 36 calories per kilogram if they are very active people. Women are at the lower end of this calorie range while men are at the higher end.
You have probably heard that burning 3,500 calories is equivalent to losing half a kilo of weight. Then to lose 1 kg of body weight, you need to create a deficit of approximately 1590 calories.
Calculation of the BMR to estimate the caloric needs
To estimate your caloric needs per kg, you can calculate your resting basal metabolic rate or BMR, and multiply it by the corresponding activity factor. For example:
- For men, BMR equals 88,362 + (4,799 x height in centimeters) + (13,397 x weight in kilograms) – (5,677 x age).
- For women, it is 447,593 + (3,098 x height in centimeters) + (9,247 x weight in kilograms) – (4, 33 x age).
This number is then multiplied by the activity factor. Remaining as follows:
- 1, 2 for sedentary people.
- 1,375 for people who participate in a light activity.
- 55 for people who are moderately active
- 75 For people who are very active.
- 9 For those people who perform physical activities.
The result is divided by your weight to obtain the number of calories per kilogram that you must consume to maintain your current weight.
How does exercise affect my caloric needs?
The aerobic exercise burns a significant amount of calories, thereby increasing the caloric needs. For example, a low-active man between the ages of 30 and 59 who weighs 75 kilograms needs about 34 calories per kilogram; In case of being active, it requires about 40 calories and about 47 calories if you are very active.
The more intense the exercise, the more calories you will need to burn per minute, so you will have to get more calories. For example, running at a rate of 8 minutes per kilometer burn approximately 0.28 calories per minute per kilogram, while walking at a rate of 12 minutes per kilometer will only burn approximately 0.08 calories per minute per kilogram. It is recommended to try to do a moderate to moderate aerobic activity for 30-60 minutes almost every day of the week.
On the other hand, although the exercise of strength training does not burn many calories compared with aerobic training, you can increase your caloric needs as it will help you build muscle. In this way you will increase your metabolism. It is suggested to try to fit at least two strength training sessions per week.
Considerations on body composition
Usually when you have more weight you need fewer calories per kilogram to maintain weight, even with the same level of activity. This is because heavier people have more body fat, and require fewer calories to maintain muscle fat.
For example a 30-year-old man who weighs 50 kilograms without the need to be very active requires more than 42 calories per kilogram, but a man of the same age who weighs 90 kilograms will only need about 31 calories per kilogram.
As you can see the different ways of estimating caloric needs do not take into account whether the weight comes from fat or muscle , this can underestimate the needs of calories in people who have more muscle as bodybuilders or athletes.
How does aging affect my caloric needs?
In general, people tend to accumulate fat as they age, due to the slowdown in metabolism. This means that as you get older you will need fewer calories per kilogram to maintain your weight. Consuming the same amount of calories will lead to an increase in weight.
Every 10 years you will have to eat around 150 fewer calories per day to avoid a potential increase in weight. Engaging in strength training to build muscle can help limit these decreases, which can be in part due to decreased muscle mass and increased fat mass.
Related Wiki Link: https://en.wikipedia.org/wiki/Calorie_restriction