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What Does a Calorie Deficit Mean?

Published on Jun 23, 2022 and last reviewed on Jun 30, 2022   -  4 min read


Calorie deficit is when the intake of calories is lower than the number of calories burnt by an individual. It is a key feature in losing weight.


What Are Calories?

A calorie is a measurement unit that measures the amount of energy (with respect to food) in the body. A calorie would be mainly defined as the unit of heat energy required to raise 1 gram of water by 1 degree Celsius. Calorie intake includes the diet, food, and beverages that one consumes on a daily basis.

The body needs a substantial amount of energy to work and carry out daily routine activities. The amount of calorie intake varies depending on the age, sex, daily physical activity, height, weight, and genetics of an individual. On average, the calorie required by an adult woman is 2000 per day and for a man is 2500, according to the Academy of Nutrition and Dietetics.

What Are the Factors Determining Calorie Intake?

The factors determining calorie intake depend on three factors mainly, the factors are:

1. Basal Metabolic Rate: Basal metabolism is the amount of energy required by the body to maintain its function in the resting state. An individual’s basal metabolic rate (BMR) is dependent on age, gender, weight, height, and development (concerning infants and children). An increase in weight increases the BMR. BMR dictates around half or more than half of the caloric needs of an individual.

2. Physical Activity: An individual’s daily activities, especially their physical activity, is dependent on their calorie intake. Physical activity accounts for about half of the calorie intake. Physical activities are not inclusive of only exercises or workout; it also includes non-exercise activity thermogenesis (NEAT). The energy consumed doing activities such as walking, cleaning, cooking, working, daily chores, etc.

3. Thermic Effect of Food: Thermic effects of food are defined as the energy consumed for digesting and absorbing food. Thermic effects due to food account for five to ten percent of the calorie intake.

4. Resting Energy Expenditure (REE): Resting energy expenditure is defined as the energy or calories utilized by the body in maintaining daily resting activities to keep oneself alive such as respiration (breathing), homeostasis and blood circulation.

What Is Calorie Deficit?

With the recent research on healthy body functions, weight loss is gaining attention. Calorie deficit has proven to be an effective way of weight loss. A calorie deficit is defined as the shortage of calories in relation to the number of calories consumed and burned. Calorie deficit follows the basic rule that the number of calories utilized (burnt) should be greater than the calorie intake.

To average out the calories or to lose weight, the amount of energy intake should be less than the amount of energy burnt; this maintains the energy homeostasis (it is a biological process that includes coordinated regulation of the energy inflow and outflow).

By lowering food intake, a calorie deficit is created; it is also known as dieting. However, it is not necessary to diet in order to create a calorie deficit. The deficit can also be created by increasing the number of calories burnt, which can be achieved by

When an individual takes in an increased amount of calories than needed, then they are in a calorie surplus. Being in a calorie surplus for an increased duration often leads to weight gain.

What Is the Purpose of Calorie Deficit?

The aim of following a calorie deficit is mainly to lose weight. Different theories or papers have been published in order to support the theory of weight loss and calorie deficit. Some of the theories are:

  1. According to the national institute of health (NIH), in the case of an overweight or obese individual, it is essential to follow a calorie deficit in order to lose weight and become healthy.
  2. The academy of nutrition and dietetics published a report in 2016 stating that about 500 to 750 kcal of calorie deficit is essential in order to lose weight.
  3. The international journal of obesity also published an article in 2014 stating that a 3500 kcal per week calorie deficit or a 500 kcal per day calorie deficit is needed by an individual in order to lose weight.

What Are the Complications Due to Calorie Deficit?

When an individual is in a calorie deficit for a longer period of time, the individual might develop or experience certain health problems. Calorie deficit puts an individual under health hazards as cutting calories can lead to a deficiency of nutrients and vitamins. Some of the health conditions developed due to calorie deficit are:


Employing a calorie deficit to lose weight, though a scientifically proven technique should be recommended as an option by a dietician, nutritionist, physician, or healthcare provider, taking into consideration the dietary needs and physical activity status of the individual. To lose weight, an individual must not only focus on a calorie deficit but also on physical activities such as exercising, running, working out, and playing sports. As much as losing weight and getting healthy is essential, so are nutrition, vitamins, and calories. Going into a calorie deficit is essential but is a double-edged sword. Cutting down calories should be marked under the supervision and with care. Professional dieticians are required in order to maintain a proper diet chart, so an individual can enter a calorie deficit and avoid any health hazard that might be a result of entering a callous calorie deficit case.

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Last reviewed at:
30 Jun 2022  -  4 min read




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