Being overweight carries heavy risks

Dr. Richard Beliveau, QMI Agency

First posted: | Updated:

It can never be said too much: next to giving up smoking, maintaining a healthy weight is one of the important factors involved in living a long, healthy life.

Amongst adults over 20, the body mass index (BMI) is a simple and generally accurate way to determine if a person is overweight. BMI is interpreted in the following way: according to criteria established by the World Health Organization (WHO), a BMI between 20 and 24 is considered to represent a normal weight. People with a BMI of under 18 are considered too thin, while those with a BMI of between 25 and 29.9 are considered to be overweight. Those with a BMI of 30 or greater are considered obese. For example, a person that is five-feet, nine inches tall and 150 pounds is at an ideal weight because it corresponds to a BMI of 24. However, if that person gains 22 pounds, the BMI will jump to 27 and suddenly this person has become overweight. Another 33 pounds will move this person into obesity. The accumulation of this excess weight is usually gradual and it is only through looking at photos over the years that you begin to realize how much weight you have put on. Because 65% of the North American population is overweight, people have become less sensitive to the problem, thus making those extra pounds seem almost normal to many in our society.

Our genetic makeup has evolved to allow our bodies to operate when faced with a lack of calories, but not with an excess of them. Numerous studies have shown unequivocally that carrying excess weight is closely linked to a spectacular increase in the risk of developing many serious illnesses, notable cardiovascular disease, type 2 diabetes and several types of cancer, thus reducing life expectancy. It is not because most people are considered overweight that this situation has become normal from a metabolic point of view. Rather, this global obesity epidemic is the result of major changes to our diet and a sedentary lifestyle. We are no longer burning the extra calories we are consuming.

The dangers associated with being overweight have been illustrated by the results of the most comprehensive studies ever conducted on the existing link between BMI and mortality risk (1). By examining data accumulated from 1.46 million non-smokers, a group of American researchers observed that the risk of premature death increases significantly for each excess kilogram of weight a person puts on. For example, an overweight person (BMI of 25 to 29), which represents the large majority of the North American population, have a 13% higher risk of dying prematurely compared to those with a normal weight (BMI between 22 and 24).

Obviously, this risk grows even more for obese people and hits astronomical proportions for those considered morbidly obese (BMI over 40). In addition to the drastically reduced quality of life associated with chronic illnesses, researchers have estimated that obesity can knock up to four years off a person's life expectancy.

Any type of excess weight is a danger to our health and the maintenance of a healthy weight is essential to live a healthy life. We all need to learn to reduce our intake of high-calorie foods by cooking for ourselves and to rediscover the the benefits of being active every day. Doing this will also contribute to reducing the strain on our health care system caused by chronic illnesses.

Shouldn't the arrival of a new year be an occasion to take on the challenge of improving both our quality of life, as well as our life expectancy? Instead of just wishing good health for the new year, why not take advantage of the opportunity to actually do something about it by getting back down to a healthy weight!

(1) Berrington de Gonzalez A. Body-mass index and mortality among 1.46 million white adults. N Engl J Med. 2010 ; 363 : 2211-2219.a