A common point for dieters is knowing how to calculate the calories in food. Knowing this value is very important to understand how much energy you supply to the body every time you eat. That way, you can make sure you follow the food plan correctly.
Knowing the energy value of food directly influences the success of your diet and health. This is a vital subject and should be considered when making a diet, whether to lose weight or gain mass.
After All, What Are Food Calories?
As its name implies, the calorie is a unit of heat — which serves, among other functions, to measure the energy converted when we ingest food and burn it. More practically, a calorie is equivalent to one-hundredth of the heat needed to raise the temperature of 1 g of water by 1 degree Celsius.
In the case of food, to know the amount of energy converted, it is necessary to add the calories produced by the macronutrients that make up a food: fats, proteins, and carbohydrates. According to a nutritionist at USP, it is scientifically proven that 1g of fat produces about nine calories. For the same amount of protein and carbohydrate, the value drops to four.
In industry, the amount of calories is measured using a bomb calorimeter. Briefly, food is placed inside the combustion chamber. Around it, in the calorimetric vessel, is a certain mass of water. It is then burned, releasing heat to the medium, and raising the water’s temperature.
Then, a thermometer shows the temperature before and after combustion. The result of this variation determines the energy or amount of calories that the food provides.
How To Calculate Your Daily Caloric Expenditure?
Those who want to lose weight need that the amount of energy consumed is less than that required by the body. Anyone who wants to gain mass should ingest more than the body uses. Therefore, in the diet, it is essential to consider the daily caloric expenditure, age, and the practice of physical exercises and activities carried out throughout the day.
To calculate the daily caloric expenditure, there are different formulas. However, the first step is to know our basal metabolic consumption (MB), that is, how many calories our body uses to maintain vital functions, such as heart rate and breathing. This is not how many calories you should consume but how much your body spends to keep you active.
To calculate the basal metabolic consumption of people between 18 and 30 years old, use the following formula:
- women: (0.062 x weight in kilograms + 2.036) x 239 = calories burned per day;
- men: (0.063 x weight in pounds + 2.896) x 239 = calories burned per day.
For those between 31 and 40 years old, the calculation changes a little:
- women: (0.034 x weight in kilograms + 3.538) x 239 = calories burned per day;
- men: (0.048 x weight in pounds + 3.653) x 239 = calories burned per day.
Now, to determine the total caloric expenditure, which includes all activities performed throughout the day, we must add the result of the previous formulas according to our physical activity. As follows, where MB equals basal metabolic consumption:
- people who exercise 1 to 3 times a week: MB x 1.3;
- 3 to 5 times a week: MB x 1.5;
- every day of the week: MB x 1.7;
- intense or professional exercises: MB x 1.9;
- sedentary: MB x 1.2.
Of course, the results are neither accurate nor 100% genuine. Therefore, they should be used as an estimate. In addition, it is always good to consult a nutritionist, as he will be able to identify your nutritional needs and indicate the best diet for you to achieve your goals.
How To Calculate Calories Per Food?
Three macronutrients are considered when calculating calories per food: carbohydrates, proteins, and fats (lipids). Knowing the amount of each of them is of paramount importance for those looking for a healthy and balanced diet.
To start the calculation, it is essential to analyze the nutritional table on food labels. It contains all the information about the composition of that product. Then you will need a reference value to calculate the number of calories per food.