According to the World Health Organization (WHO), obesity is characterized by “an abnormal or excessive accumulation of body fat that can affect health”.
Basically, obesity results from excessive consumption of calories relative to energy expenditure for several years.
Obesity must be distinguished from overweight, which is also overweight, but less important. For its part, morbid obesity is a very advanced form of obesity. It would be so damaging to health that she would lose 8 to 10 years in life.
We cannot rely solely on a person’s weight to determine if they are obese or overweight. Different measures are used to provide additional information and to predict the impact of obesity on health.
- Body mass index (BMI). According to WHO, it is the most useful, although approximate, tool for measuring overweight and obesity in an adult population. This index is calculated by dividing the weight (kg) by the size squared (m 2). Overweight or overweight is 25 to 29.9; obesity when he equals or exceeds 30; and morbidly obese if it equals or exceeds 40. The healthy weight corresponds to a BMI between 18.5 and 25.
– The main disadvantage of this measurement tool is that it gives no information on the distribution of fat reserves. However, when fat is concentrated mainly in the belly region, the risk of diabetes and cardiovascular disease is higher than if it concentrates in the hips and thighs, for example.
– Moreover, BMI does not distinguish between the mass of bones, muscles (muscle mass) and fat (fat mass). As a result, BMI is imprecise for people with large bones or being very muscular, such as athletes and bodybuilders;
- The waistline. Often used in addition to BMI, it can detect excess fat in the abdomen. There is talk of abdominal obesity when waist circumference exceeds 88 cm (34.5 inches) for women and 102 cm (40 inches) for men. In this case, the health risks (diabetes , hypertension , dyslipidemia, cardiovascular diseases , etc.) are considerably increased. Click here to find out how to measure your waistline .
- The waist / hips ratio. This measure gives an even more accurate idea of the distribution of fat in the body. The ratio is considered high when the result is greater than 1 in men, and greater than 0.85 in women.
Researchers are working to develop new tools for measuring excess fat. One of them, called fat mass index or IMA, is based on the measurement of the hip circumference and the size. However, it has not yet been proven and is therefore not used in medicine at the moment.
To assess the existence of disease risk factors, a blood test (especially the lipid profile) gives valuable information to the doctor.
Obesity in numbers
The proportion of obese people has increased over the last 30 years. According to the World Health Organization (WHO), the prevalence of obesity has reached epidemic proportions globally. The increase in average weight is observed in all age groups, in all socio-economic groups.
Here are some data.
- In the world, 1.5 billion adults 20 years and older are overweight and at least 500 million of them are obese. Developing countries are not spared;
- In Canada , according to the most recent data, 36% of adults are overweight (BMI> 25) and 25% are obese (BMI> 30);
- In the United States , about a third of people aged 20 and over is obese and another third are overweight ;
- In France, nearly 15% of the adult population is obese, and about a third are overweight .
When we try to understand why obesity is so widespread, we find that the causes are multiple and do not rely solely on the individual. Government, municipalities, schools, agribusiness, etc. also bear some responsibility for creating obesogenic environments.
The term obesogenic environment is used to describe a living environment that contributes to obesity:
- accessibility to foods high in fat , salt and sugar , high calorie and low in nutrients (junk food);
- lifestyle sedentary and stressful ;
- Environment not conducive to active transportation (walking, cycling).
This obesogenic environment has become the norm in many industrialized countries and is found in developing countries as the population adopts a western lifestyle.
People whose genetic makeup makes weight gain easier are more likely to be victims of the obesogenic environment. However, susceptibility to genes cannot lead to obesity alone. For example, 80% of Arizona’s Pima Indians today suffer from obesity. However, when they followed a traditional way of life, obesity was much rarer.
Obesity can increase the risk of many chronic diseases. Health problems would begin to appear after about 10 years of being overweight.
Risk greatly increased:
- of type 2 diabetes (90% of people with this type of diabetes have a problem with overweight or obese);
- of hypertension ;
- of gallstones and other problems in the bladder;
- dyslipidemia (abnormal lipid levels in the blood);
- shortness of breath and sweating;
- Of apnea sleep .
Moderately increased risk:
- cardiovascular problems: coronary disorders, stroke , heart failure , cardiac arrhythmia ;
- of osteoarthritis of the knee;
- Of gout .
Slightly increased risk:
- some cancer : hormone-dependent cancers (women, endometrial cancer, breast, ovarian, cervical, in men, the prostate cancer ) and the system-related cancers digestive ( cancer of the colon , gallbladder, pancreas, liver, kidney);
- decreased fertility in both sexes;
- Dementia, low back pain , phlebitis and gastro-esophageal reflux .
The way in which the fat is distributed over the body, rather to the abdomen or the hips, plays a determining role in the appearance of diseases. The accumulation of fat in the abdomen, typical of android obesity, is much more risky than the more uniform distribution (gynoid obesity). Men have, on average, twice as much abdominal fat as premenopausal women.
Of concern, some of these chronic diseases, such as type 2 diabetes , now occur in adolescence, given the growing number of overweight and obese youth.
Obese people have a poorer quality of life by age and a life expectancy shorter than people who have a healthy weight. In fact, health professionals predict that today’s youth will be the first generation of children whose life expectancy will not exceed that of their parents, mainly because of the increasing frequency of obesity. Infant.
Finally, obesity can become a psychological burden. Some people will feel excluded from society because of the beauty criteria offered by the fashion industry and the media. Faced with the difficulty of losing their excess weight, others will experience great distress or anxiety , which can lead to depression .
Symptoms of Obesity
Obesity results in an excess of adipose tissue. This excess can be divided in 2 different ways:
- in the abdominal region, this is called android , visceral or abdominal obesity ;
- At the hips, thighs and periphery, called gynoid, peripheral or subcutaneous obesity.
For hormonal reasons, android obesity affects mostly men; and gynoid obesity, women.
People at risk for Obesity
- People who live in the United States or who immigrate to it. According to a study, one year after their installation in the United States, 8% of immigrants are obese. After 15 years, 19% have become, which is close to the American obesity rate of 22%. The most significant weight gain would occur after 10 years;
- People whose hereditary baggage predisposes to obesity.
Obesity depends mainly on environmental factors (palatables with high energy density, sedentary lifestyle, stress), but also genetic factors. The obesogenic environment we live in is particularly harmful for people who are genetically predisposed to obesity. Predisposition to obesity is dependent on more than one gene (polygenic obesity), with monogenic (single-gene dependent) forms of obesity being rare (approximately 5% of severe obesity).
The combination of an obesogenic environment and a genetic predisposition is likely to lead to the development of obesity.
Some ethnic groups are more likely than others to gain weight. This would be the case for those who have had to survive great famines because their bodies have learned to “store” calories very efficiently. When these groups are exposed to a Western lifestyle, they are at greater risk of obesity (for example, Arizona Pimas Indians, Australian Aborigines, and immigrants from India and Pakistan). ;
- Age. Over the years, we are less active and the muscle mass tends to decrease, thus slowing down the metabolism. Calorie needs decrease with age. If you do not reduce your food intake, you gain weight;
- In Canada, people who live in suburban or region are more at risk because they are less physically active than urban dwellers. However, globally, the prevalence of obesity is higher among urban populations than rural populations;
- Some diseases can cause weight gain by making it inactive. Others will contribute to weight gain by lowering energy expenditure, but they are rare: hypothyroidism, Cushing’s disease (a problem with the adrenal glands) or a tumor of the hypothalamus;
- People struggling with bulimia;
- People who were overweight during childhood or adolescence;
- The pregnancy may contribute to weight gain.
Risk factors for obesity
Individual factors that lead to weight gain
- Eating behaviors For example: regularly eating large portions, having a diet that often contains foods high in fat, salt or sugar, eating irregularly, which encourages food compulsions. These behaviors are sometimes influenced by emotional states. This is the case if one eats to escape boredom, loneliness, stress, anxiety, etc., or if food becomes a means of rewarding oneself;
- A sedentary lifestyle. Work and sedentary leisure (television, video games, Internet, etc.) have become the norm. A study in England shows that in early 1990, only 20% of men and 10% of women had a job that requires physical activity ;
- The stress. Weight gain often occurs during a period of adjustment or following an important test, for example major professional challenges or loss of employment, separation, bereavement, etc. The tendency to compensate by eating comfort foods is then stronger;
- A deep distress. Food compulsions may reflect temporary boredom, but they may be a sign of great psychological distress. Eating then becomes a survival mechanism, to soothe a suffering and a state of being unbearable;
- The family cultural heritage. Lifestyle habits – preparation and sharing of meals, activities – are influenced by the family;
- The lack of sleep can increase hunger;
- Some medications can cause weight gain when taken for a long time, including some antidepressants, antipsychotics, corticosteroids (oral or injection) and beta blockers;
- Drinking alcohol frequently can lead to weight gain by increasing caloric intake and stimulating hunger (hence alcoholic drinks as an appetizer, to open the appetite).
Social factors and changes that contribute to weight gain
- A food industry that offers a multitude of foods high in calories, fat, salt and sugar. These foods are easily accessible at any time of the day and at low prices. The huge sums invested in promoting “junk” food to the public are also being blamed;
- On television, the majority of children’s food advertisements promote dubious or downright unhealthy foods. Studies show that advertisements greatly influence children’s eating preferences, according to the US Institute of Medicine of the National Academies ;
- Advertisements, as well as the media , that encourage thinness;
- Due to the difficult work-family balance, many parents are resorting more and more often to prepared meals or restaurants. Meals are less family friendly. As a result, parents have less control over what their children eat and education about healthy eating is compromised;
- A more assiduous of restaurants ;
- The ever-increasing portion sizes in restaurants and the supermarket;
- The automation of work and the technological evolution, which make physical activity less and less necessary on a daily basis. Not only is work sedentary, but many workers frequently experience psychological pressure and stress;
- An urban development that does not encourage walking and physical activity;
- The loss of sense of security in neighborhoods, resulting in children playing less outdoors, using little walking or cycling to get to school, etc.
Prevention of obesity
|Basic preventive measures|
|The prevention of obesity can begin, as it were, as soon as one begins to eat. According to the studies, the risk of obesity is closely related to eating behavior during childhood.
Already, from 7 months to 11 months, American infants would consume 20% too many calories compared to their needs. A third of American children less than 2 years do not eat fruits and vegetables, and among those who consume, fries come top of the list. As for Quebecers aged 4, they do not eat enough fruits and vegetables, dairy products and meat and alternatives, according to the Quebec Institute of Statistics.
Consuming slimming products and dieting under strict diets without changing your eating habits is certainly not a good solution. Healthy eating should be varied and include fresh fruits and vegetables. Eating well involves cooking one’s own meals, replacing certain ingredients, flavoring foods with herbs and spices, taming new cooking methods to use less fat, and so on. Check our Nutrition factsheet for the basics of healthy eating.
Some advice to parents
Physical activity is an essential part of maintaining a healthy weight. Moving increases muscle mass, therefore energy needs. Encourage the children to move, and move with them. Limit TV time as needed. A good way to be more active everyday is to frequent the small businesses in your neighborhood by walking.
Many studies indicate that sleep well help control weight. Lack of sleep may encourage more eating to compensate for lower energy levels in the body. In addition, it could stimulate the secretion of hormones that trigger the appetite. To discover ways to sleep better or overcome insomnia,
Reducing the sources of stress or finding tools to better manage them can make it less likely to calm down with food. In addition, stress often makes eating faster and more necessary. Check out our Stress and Anxiety chart to find out more about ways to better cope with stress.
Act on the environment
To make the environment less obesogenic, so that health choices are easier to make, the participation of many social actors is necessary. In Quebec, the provincial Task Force on Weight-Related Problems (GTPPP) proposed a series of possible actions the government, school communities, workplaces, the food industry, etc. to prevent obesity :
Medical treatments for obesity
More and more experts say that the main goal of treatment should be to adopt better lifestyle habits. Thus, present and future health is improved. The resulting weight loss should rather be considered a “side effect”.
A global approach
The most effective approach to improving one’s long-term health is personalized, multidisciplinary and requires regular monitoring. The therapeutic approach should ideally include the services of the following professionals: a physician, a dietitian, a kinesiologist and a psychologist.
One must begin with a checkup established by a doctor. This is followed by consultations with other health professionals. It is better to bet on a follow-up spread over several years, even during the phase of maintenance of the weight. Unfortunately, few clinics offer such support.
According to experts at the Mayo Clinic in the United States, a weight loss of 5% to 10% of body weight can improve health significantly. For example, for a person weighing 90 kilos, or 200 pounds (and being obese based on his body mass index), this corresponds to a weight loss of 4 to 10 kilograms (10 to 20 pounds).
|Dieting: to be avoided
Most weight loss diets are ineffective at losing weight in the long run, in addition to being risky, say studies. Here are some possible consequences:
With the help of a dietician-nutritionist, it’s about finding a nutritional approach that suits our own tastes and lifestyle, and learning to decipher our eating behaviors.
On this subject, see two articles written by our nutritionist, Hélène Baribeau:
Increasing energy expenditure helps a lot in weight loss and improves general health. It is safer to consult a kinesiologist before starting a physical activity. Together, you will be able to choose a training program appropriate to your physical condition and your interests.
Consult a psychologist or psychotherapist can help to understand the origin of excess weight, changing some eating habits, to better cope with stress and regain their self-esteem, etc. Consult our page Psychotherapy.
Some prescription medications can help you lose weight. They are reserved for people with significant risk factors for cardiovascular disease, diabetes, hypertension, etc. These drugs cause modest weight loss (2.6 kg to 4.8 kg). We must continue to take them for the effect to remain. In addition, they must be associated with a strict diet and have several contraindications.
- Orlistat (Xenical). The effect is a reduction in dietary fat absorption of about 30%. Undigested fat is excreted in the stool. It must be accompanied by a low fat diet to avoid or reduce adverse effects.
Common side effects: oily and oily stools, urge to bowel, flatulence, abdominal pain.
Note. In the United States and Europe, orlistat is also available over-the-counter at half the dosage, under the trade name Alli (in France, the drug is kept behind the counter of the pharmacist). The drug Alli is for overweight people. It is likely to cause the same types of side effects as Xenical. It must also be accompanied by a low fat diet. Contraindications apply. It is recommended that you consult a physician before starting treatment with this medicine to obtain a checkup and a comprehensive approach to weight control.
|Note that Meridia (sibutramine), an appetite suppressant, is no longer on the Canadian market since October 2010. This is a voluntary withdrawal by the manufacturer, following discussions with Health Canada . This medicine increases the risk of myocardial infarction and stroke in some people.
The bariatric surgery is usually to reduce the size of the stomach, which reduces the intake of food by about 40%. It is reserved for people who are morbidly obese, that is to say, those with a body mass index over 40, and those with a BMI greater than 35 who have a disease related to obesity.
Note. Liposuction is a cosmetic surgery and should not be used to lose weight, according to experts at the Mayo Clinic in the United States.
|Some immediate benefits of weight loss