Weight lost


Weight loss refers to a decrease in your overall body weight from muscle, water, and fat losses. Fat loss refers to weight loss from fat, and it's a more specific and healthful goal than weight loss. A calorie deficit is when a person consumes less calories than they burn. A person’s individual health and circumstances will affect their calorie needs.


This webquest intends to show how to diet in order to lose weight.


A calorie deficit occurs when the number of calories a person consumes daily is smaller than the number of calories they burn.

The body needs to burn a certain number of calories to perform all its functions each day.

How many calories a person needs each day variesTrusted Source based on their:

  • sex
  • age
  • physical activity levels
  • height
  • weight
  • body composition

A person can create a calorie deficit by reducing the number of calories they eat, increasing their activity levels, or both.


There are several ways to determine how many calories a person normally burns daily.

For example, they can opt to calculate their daily calorie needs manually or find an online calculatorTrusted Source.

To perform a manual calculation, moderately active people can multiply their current body weight by 15 to estimate how many calories they would need each day. Anything less than this is a deficit.

Basal metabolic rate

A person can also use their basal metabolic rate (BMR) and activity levels to determine their current caloric needs. They can use one of the following formulas to determine their BMR, according to their sex:

  • adult male: 66 + (6.3 x body weight in lb) + (12.9 x height in inches) – (6.8 x age in years) = BMR
  • adult female: 655 + (4.3 x weight in lb) + (4.7 x height in inches) – (4.7 x age in years) = BMR

Once a person has their BMR, they can use one of the following formulas, based on their 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 per week of moderate activity or sports = BMR x 1.55
  • Very active: 6–7 days per week of hard exercise = BMR x 1.725
  • Extra active: athletes who train twice per day, for example = BMR x 1.9

People can also ask their doctor or nutritionist for the most accurate caloric intake estimates. These professionals can tailor the estimate based on the person and their lifestyle.


How to create a calorie deficit 

Once a person knows how many calories they need each day or week, they can work on creating a calorie deficit.


One component in creating a calorie deficit is changing what a person eats and drinks daily. A person should focus on foods that are rich in nutrients but low in calories.

According to the Dietary Guidelines for Trusted SourceAmericans 2020–2025Trusted Source, a healthful eating pattern with fewer calories should include:

  • whole vegetables
  • whole grains
  • whole fruits
  • lean proteins
  • low fat or fat-free dairy, including milkyogurt, cheese, or fortified soy beverages
  • ‘healthy’ oils such as olive or canola

A person should also avoid consuming sugary drinks and trans fats.


An important part of weight loss is exercise. An inactive person should try to increase their daily activity levels if they can.

The Centers for Disease Control and Prevention (CDC)Trusted Source recommends 150 minutes of moderate activity and two sessions of strength training per week to maintain a moderate weight. The more physically active a person is, the more calories they will burn. This increases the number of calories they need, making creating a deficit easier.

This can include activities such as:

  • walking
  • taking the stairs instead of the elevator
  • hiking
  • playing sport
  • biking


When reducing calorie intake, hormonal changes, water retention, and alterations in fat storage can cause people to stay the same numerical weight. However, this does not mean that a person is not experiencing body composition changes.


Plainly, a calorie deficit is essential to lose weight. However, this may not occur consistently, and many factors can impact weight lossTrusted Source progress.