Does a caloric deficit help you lose weight?

Weight loss is closely linked to caloric deficit. However, we may be wondering what exactly it involves or why it is necessary for weight loss.

To lose weight, it is convenient to know what a calorie deficit is, how it affects weight loss and how to achieve it in a healthy and sustainable way.

What is?

Calories are the units of energy you get from food and drinks, and when we consume fewer calories than we burn , we get a caloric deficit. When there is a calorie deficit, the body gets energy or fuel from stored fat. In this case, stored fat is stored energy. So when the body burns fat for energy, we lose weight.

The calories you burn or expend each day, also known as calorie expenditure, include the following three components:

  • Resting energy expenditure. This refers to the calories that the body uses at rest for functions that keep us alive, such as breathing and blood circulation.
  • Thermic effect of food. This involves the calories the body expends digesting, absorbing, and metabolizing food.
  • Energy expenditure of the activity. This refers to the calories you expend during sports such as exercise and non-exercise activities, including fidgeting and housework.

If we give the body fewer calories than we need to support these three components of calorie expenditure, we are putting the body in a calorie deficit. If we do it consistently for long periods, weight loss will be obtained. On the contrary, we will gain weight if we give the body more calories than we need to perform these functions. This is called a caloric surplus.

mujer midiendo su déficit calórico

Daily Calorie Calculation

For most people, a caloric deficit of 500 calories a day is enough to lose weight and is unlikely to significantly affect hunger or energy levels.

To create this calorie deficit, we need to know what the maintenance calories are. Maintenance calories are precisely the number of calories the body needs to support energy expenditure. Calorie calculators can be used to estimate calories based on weight, gender, age, height, and physical activity level.

Although calorie calculators give a good idea of ​​maintenance calorie needs, we can get a more accurate number by tracking your calorie intake and weight over 10 days . While maintaining the same level of daily activity, we will use a calorie tracking app to monitor daily calories and weight. To obtain an accurate result, we will use the same scale, at the same time of day and with the same clothes (or naked).

Weight can fluctuate from day to day, but if weight has been stable over the 10 days, the average number of calories we consume per day is a better representation of maintenance calories. We will divide the total number of calories we consume for 10 days by 10 to find the average daily caloric intake. We will then subtract 500 calories from this number to determine the new daily intake goal for weight loss. For example, if we set maintenance calories to 2,000 a day, the new daily calorie goal would be 1,500.

As we lose weight, maintenance calories will decrease over time and we will need to adjust calorie intake based on weight loss goals. Still, to ensure healthy weight loss and adequate nutrient intake, women should consume no fewer than 1,200 calories per day and men no fewer than 1,500 calories.

Basal metabolic rate and activity levels can also be used to determine current calorie needs. One of the following formulas can be used to determine it, depending on gender:

  • Adult male: 66.5 + (13.8 x weight in kg) + (5 x height in cm) – (6.8 x age in years)
  • Adult female: 655 + (9.6 x weight in kg) + (1.85 x height in cm) – (4.7 x age in years)

Once a person has their basal metabolic rate, one of the following formulas can be used, depending on activity levels, to determine their caloric need:

  • Sedentary: little or no exercise = BMR x 1.2
  • Minimally active: 1–3 days per week of exercise or activity = BMR x 1.375
  • Moderately active: 3–5 days a week of moderate activity or sports = BMR x 1.55
  • Very active: 6–7 days a week of vigorous exercise = BMR x 1.725
  • Extra active: athletes who train twice a day, for example = BMR x 1.9

medidor para déficit de calorias

How to achieve a caloric deficit?

We can achieve a calorie deficit by consuming fewer calories or by increasing physical activity levels, or both. It may be easier and more sustainable to create a calorie deficit through diet rather than just exercise, since we may not have the time, energy, or motivation to exercise every day. Also, exercise doesn’t burn as many calories as many people think.

In other words, it may be easier to eat 500 fewer calories each day than it is to burn this many calories through exercise. However, it is recommended to participate in aerobic and muscle strengthening exercises for their beneficial effects on general health.

3,500 calorie rule

Some nutrition experts suggest that you need a caloric deficit of 3,500 calories a week to lose a pound of fat. In this case, cutting 500 calories a day helps achieve this goal.

Science suggests that the notion that there are 3,500 calories in a pound of fat dates back to the 1950s, when Max Wishnofsky, a New York doctor, wrote this in a report. Since then, many health professionals have continued to echo this statement.

Difficulty in caloric deficit

The researchers say that the idea of ​​a 3,500-calorie deficit resulting in fat loss greatly overstates actual weight loss.

Some studies support that those who reduced their caloric intake by a certain amount each day lost much less weight than expected under the 3,500 calorie rule. Losing weight is more of a curve than a line.

That is, even if we eat fewer calories than we expend, weight loss slows down instead of continuing at the initial rate. Some dietitians agree, adding that various factors affect weight loss, from gender to exercise habits.


Reducing calories from the diet to create a calorie deficit does not necessarily require drastic changes. In fact, there are several tricks that can help you reduce your calorie intake for weight loss.

Don’t drink the calories

We may be able to cut several hundred calories from the diet simply by reducing or eliminating consumption of sugary beverages such as soft drinks, fruit juices, and specialty coffee drinks. Alcoholic beverages can also contain a significant amount of empty calories.

The calories in these drinks do not provide satiety and, in excess, can lead to weight gain, heart disease and diabetes.

Limit ultra-processed foods

The sugar, fat, and salt in highly processed foods, including sodas, fast foods, desserts, and breakfast cereals, make these high-calorie foods highly palatable and encourage overconsumption.

Minimally processed foods are rich in vitamins, minerals, and fiber and include foods like lean protein, fruits, vegetables, nuts, and legumes. A diet rich in minimally processed foods will help us avoid overeating and ensure we get the nutrients our bodies need.

make home cooked meals

Preparing and eating meals at home allows you to control ingredients and portion sizes. One study showed that people who cooked dinner at home most days of the week ate 137 fewer calories per day.

Eating home-cooked meals is also associated with better diet quality, higher fruit and vegetable intake, lower levels of body fat, and lower risks of heart disease and diabetes. Also, it can save us money.


An important part of weight loss is exercise. A person who is not active at all should try to increase their daily activity levels if they can. This can include activities such as walking, taking the stairs instead of the elevator, playing a recreational sport, or riding a bike.

The more physically active a person is, the more calories they will burn. This increases the number of calories they need, which can make it easier to create a caloric deficit.