The body needs energy to function, and it burns that energy to do so; when more energy is burned than we consume, there is a caloric deficit. The caloric deficit is important to lose weight; if there is no caloric deficit, the weight will not decrease.
What does the caloric deficit mean?
When we talk about losing weight or something much better for our health, losing fat, we must be in a caloric deficit. What does it mean? The body needs energy to function and burns it to do so. When more energy is burned than we consume, suppose a person consumes 2,000 kcal per day, but his body needs 2,500 kcal; he would have a caloric deficit of 500 kcal.
How can we calculate our caloric deficit?
We need to know how many calories we need to calculate the caloric deficit. But what are calories? They are a measure of heat or energy. Specifically, it is the amount of heat necessary to produce a temperature increase of 1ºC in a sample of 1 gram/calorie water. In the body, calories are a form of energy, food contains energy/calories, and depending on the food we eat, we will have more or less energy. And, if it is left over, it is stored as body fat.
To calculate the necessary caloric intake, it is necessary to know the calories we ingest through food and the calories spent daily with the activity we carry out.
There are different mathematical formulas to calculate a person’s Basal Metabolic Rate (BMR), the number of calories the body consumes at complete rest. The American Journal of Critical Care proposes the Mifflin St. Jeor equation:
- Men: BMR = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) + 5
- Women: BMR = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) – 161
The physical activity factor (FAF) must be applied to this expense, and depending on whether you have a sedentary or very active life, it will be multiplied by one or the other factor (FAO/WHO data):
- Sedentary: you work sitting down and do not exercise: BMRx1.2.
- Light activity: you work standing up, driving, and walking slowly… if you exercise 1-3 times a week: BMRx1,375.
- Moderate activity: you work by walking fast, cleaning, carrying weight… Sports are practiced 3-5 times a week: BMRx1.55.
- Active: works in construction, climbing stairs… Sports are practiced 6-7 times a week: BMRx1,725.
- Very active: strength work, running… Sports are practiced two h a day: TMBx1.9.
Example:
A 60 kg, 165 cm, a 30-year-old woman has a BMR of:
- BMR=(10×60) + (6.25×165) –(5×30)-161 = 1320.25
- With a Moderate activity (1.55): 1320.25×1.55= 2046.9kcal needed per day.
- The energy intake will be below this 2046.9kcal per day to achieve a caloric deficit.
When should we calculate caloric needs?
If you maintain a healthy diet, an adequate weight, and an active life, it is not necessary to calculate your energy needs since you probably enjoy an adequate weight and a good state of health. It is more common to perform this calculation when you are overweight or obese, when there are associated pathologies that require a higher energy intake, or when there is a tendency to lose weight.
Is a caloric deficit important to lose weight?
If there is no caloric deficit, the weight will not decrease. You can follow an omnivorous, vegan, vegetarian diet… but there must be a caloric deficit to lose weight.
How to apply the caloric deficit to the usual diet?
Food provides calories; depending on the type of food we choose, the amount of calories we will ingest will vary greatly. It is not a matter of counting the calories provided by each of the foods we eat daily, since it is not practical or realistic, since on many occasions, the degree of maturity of a fruit or if the fish is wild or farmed can vary. The calories. In our country, nutrition professionals tend not to focus so much on calories but rather on the person knowing how to choose the healthiest and most appropriate type of diet for them.
Adjust caloric intake
A good way to adjust caloric intake to lose weight is to apply the plate method, which is based on using the plate visually and thus distributing the food in the appropriate proportions to prepare menus, ensuring a correct composition and adapting the quantities according to age and energy needs. The visual distribution of the food on the plate will be:
- 50% vegetables: preferably fresh, seasonal, and local, as they have better taste, smell, and nutritional quality. They provide little energy and many vitamins, minerals, and fiber.
- 25% whole grains and tubers: this group includes potatoes, sweet potatoes, bread, rice, corn, and quinoa… preferably whole grains. Carbohydrates mainly provide energy in addition to vitamins, minerals, and fiber.
- 25% lean meat, fish, eggs, and legumes (chickpeas, beans, lentils, peas…). Fatty meats, sausages, cured meats, and smoked meats are excluded and, therefore, for punctual consumption, due to their high saturated fat content. They provide proteins, mainly to create and repair the body’s cells and promote optimal bone and muscle growth.
The dish is accompanied by water and fruit for dessert. When eating two dishes, one whole or half of the first and half of the second must be vegetables so that it continues to represent 50% of the intake. The amounts of each food group will vary depending on the calories the person will need.
Adapt physical activity
It is not simply reducing calories from the diet, as the body can adapt and function on fewer calories/energy over time. Regular physical activity and maintaining it over time is the most appropriate way to increase energy expenditure. If the person already practices physical activity regularly and still finds it difficult to lose weight, it would be convenient to assess the type of activity, and it may be necessary to intersperse it with a different physical activity to which the body is not so accustomed. For example, instead of always doing 30 minutes of jogging on the treadmill at the gym, try a HIIT workout, or switch from a treadmill to a spinning bike. It is also highly advisable to combine cardiovascular exercise with strength exercise.
Conclusion
The calculation of the caloric deficit has a solid scientific basis, but even with the detailed information, it is not always as simple as the numbers obtained from the formulas seem to indicate. It is important to analyze by a professional, in this case, the dietitian nutritionist, the daily eating habits, the physical activity habits, the level of stress, the adaptation of the diet to the particular person… everything to achieve the changes of habits are sustainable in the long term and thus be able to maintain the good results, setting realistic goals and knowing that weight loss is achieved if a healthy lifestyle is maintained and never with “miracle” diets.
