Body weight includes lean mass (e.g., muscles, bones) and fat mass. It is influenced by several factors and can vary over a person’s lifetime.

In terms of health, body weight is a risk factor, just like smoking, a sedentary lifestyle, physical inactivity or a poor diet. Adopting a physically active lifestyle and a healthy diet will have benefits for your health and well-being, whatever your body weight. Adopting a healthy lifestyle is good for everyone.

Being overweight increases the risk of developing, for example:

  • type 2 diabetes;
  • high blood pressure;
  • cardiovascular disease;
  • several types of cancer, such as colorectal cancer or cancers of the pancreas, kidney, breast, uterus and ovary;
  • osteoarthritis (type of arthritis).

Various measures are used to assess the health risks associated with body weight for adults. However, they are not intended for use with pregnant or breastfeeding women.

Body mass index

Body mass index (BMI) is calculated by dividing a person’s weight by the square of their height. The formula is as follows: BMI = weight (kg)/height (m)2. If the value is less than 18.5 or higher than 25, you are at increased risk of developing health problems.

However, BMI does not distinguish between fat and muscle, which can influence the assessment of risk for some adults. To get a complete analysis of your weight, measure the circumference of your waist too.

Waist circumference

Measuring your waist will tell you if you are carrying fat around your abdomen. Use a tape measure to measure your waist circumference.

A large waist circumference, even if not overweight, is associated with an increased risk of developing chronic diseases such as cardiovascular disease and type 2 diabetes. A waist circumference over 94 cm in men and over 80 cm in women is associated with an increased risk.

Go to the Healthy weight and waist This hyperlink will open in a new window. page on the Heart and Stroke Foundation’s website to learn more about waist circumference, including how to measure it, and BMI.

Beware of weight loss diets

There is no miracle recipe for losing weight without gaining it back in the following months. Repeated attempts and the methods used to lose weight can have health risks.

Weight loss diets are often very severe and difficult, even impossible to follow in the long term.

When you go on a diet, your body tends to reduce its energy expenditure. Once the diet is over, when you start to eat like you used to again, or more than before because of the deprivation, your body is afraid that it will be faced with another energy deficit. So it stores the calories that it finally gets as fat. This means the person regains the weight they lost and often more. The more diets a person follows, the more the body tries to safeguard its reserves and the harder it is to lose weight.

Many diets are based on cutting out certain foods. But a food that is forbidden becomes appealing. Indeed, studies show that when a person deprives themselves completely or unreasonably of a particular food, the desire to eat that food increases and so they eat more of it.

To reduce the amount of energy consumed, several diets recommend reducing the portions of foods eaten. However, each person has their own energy and calorie needs and the portions suggested do not suit everyone. The only way to make sure you consume the amount of food that meets the body's needs is to listen to the hunger and satiety signals that it sends.

Do not hesitate to consult a health professional before taking steps to change your weight.

Useful websites

You will find additional information on the following websites: