Two scientific perspectives on obesity

Rates of obesity and abdominal obesity have doubled in Quebec over the past 30 years. 17-year-olds weigh on average 7 kg more¹. For what ? And how to react without causing harm? Meeting with two researchers who approach the question from different angles.

Who is Benoit Arsenault?

Epidemiologist, Benoit Arsenault is interested in population statistics. According to his team, weight variability is primarily explained by genetics, and we must encourage inclusive approaches, which are not focused on weight. He is a professor at the faculty of medicine at Laval University.

Who is Paul Poirier?

Cardiologist and prevention specialist, Paul Poirier sees patients. For him, the increase in obesity is a symptom of our lifestyles, and we must respond to it with policies that promote healthy eating and physical activity. He is a professor at the faculty of pharmacy at Laval University.

How to explain the increase in the obesity rate?

PP: Benoit will tell you that it’s genetics. I will tell you that it is the symptom of a sick society. We have the same genetics as 30, 40 years ago, but it is expressed in a bad environment. The best example is the pandemic. I saw people who learned to bake bread, who no longer went out after 8 p.m. and who gained 30 pounds. Is it genetics? No, it’s the environment.

BA: I think genetics explains a large percentage of the variability in weight in the population, but I completely agree that there have been huge changes in our dietary environment, in energy expenditure, in more stressful environments and mental health issues. It awakened a genetic susceptibility to obesity. In fact, in my opinion, we should rather ask ourselves: why aren’t we all fat today? It’s not just because thin people exercise a lot and eat like Tibetan monks. This is also partly explained by genetic susceptibility.

PP: Genetic factors that predict fat distribution exist. But every day in the clinic, someone says to me: “I have big bones, I’ve always been big. » He’s gained a pound a year for 40 years, he’s become severely obese, but he tells me he eats well and exercises. Then he had bariatric surgery, and he lost weight. How come ? It’s not genetics.

It is very difficult to lose weight sustainably by changing your lifestyle habits…

PP: It’s always difficult. Human beings want to have everything at the same time! Taking a post-infarction beta blocker takes five seconds, but being active and paying attention to what you eat every day… Take the word “lunch”. Breakfast. Break the fast. People eat in the evening in front of the television and don’t notice it. That’s behavior.

BA: That’s all well and good saying all that, Paul, but when you look at the studies that try to get people to lose weight, it works for a few months, and then after that, everyone goes back to their original weight.

PP: Block elevators, tax a can of Coke to cost $3.50, make milk 50 cents a glass. People who make the right choices are because they can afford it. Those who eat scrap, it’s because that’s what they can afford. I have patients who tell me that all they can afford is Pepsi and hot dogs. They cannot afford quality food.

For your part, Benoit Arsenault, do you find the increase in obesity rates in Quebec worrying? If so, what solutions do you recommend?

BA: It’s extremely complex. I am not denying that being overweight increases the risk of developing all sorts of diseases or the impact on health care associated with the increase in the number of overweight people. But once we say that, what is the solution? It is obvious that changing our eating habits is more a matter of political decisions than of individual decisions in terms of public health. It’s the same thing for physical activity. We see it in studies: changing your diet and moving more on a daily basis reduces the risk of cardiovascular events, developing type 2 diabetes, etc. But these same studies show that it does not cause weight loss on the scale. We must therefore move from a society that stigmatizes people with high weight to one that offers inclusive approaches to weight.

By eating better and moving more, can a fat person escape the diseases that, statistically, threaten them?

BA: In epidemiology, zero risk does not exist. There are other genetic factors. Thin people who have heart attacks, there is one and then another! You can reduce your risk, yes, but not by following diets. The more weight you lose, the more you gain back, and after three or four years, you weigh more than you did at the start. Rather, it is by changing your lifestyle habits in a lasting way that you can change the trajectory of your risk.

PP: In Colorado, there is a cohort of ex-obese people who have become marathon runners. The price of staying slim is working out a lot, because the body is wired to regain lost weight. The principle is not to become obese, and to show children what to do. Because right now, kids are being taught to be sedentary.

In closing, what is your vision for the future?

PP: We are in the process of medicalizing obesity, just as we medicalized hypertension, until we decided to cut out salt in processed foods. When will it happen for obesity? Will it take a molecule for you to think about losing visceral fat? That doesn’t make any sense. We can’t afford it.

BA: I’m going to be a little more positive. I think the public discourse is changing on issues associated with weight and health. Today, six out of ten Quebecers feel inadequate because they are overweight. We must remove this burden from them and tell them to change their lifestyle habits, regardless of the effect on the scale. When people understand this, we will make progress in both metabolic health and mental health.

1. According to a study by Professor Mario Leone carried out with a sample of 4,500 students aged 6 to 17 and published in August in the Canadian Journal of Public Health.