Dr. Jason Fung
Specialist Physician, Nephrologist and Author of The Obesity Code
Question 1: Rates of obesity, prediabetes, and Type 2 diabetes continue to rise across Canada. What do you believe are the biggest factors driving this trend, particularly among men?
The obesity epidemic really started in the late 1970s with the release of the Dietary Guidelines for Americans. This encouraged people to eat very little fat and replace it with carbohydrates – bread, rice, potatoes. Most of these carbohydrates were highly refined and this led to a gradually increasing weight.
This was further sustained by the rise of ultra-processed foods (UPFs). The Dietary Guidelines urged us to eat low fat and one way to reduce dietary fat was to process foods and remove fat and usually add other things – sugars, sweeteners, chemicals etc. It was widely believed that it was better to eat a highly processed low fat food (Snackwells) instead of a natural high fat food (salmon or avocados). The dietary guideline indirectly contributed to the massive boom in UPFs which have come to dominate the food environment constituting almost 60-70% of the American diet today.
The increased obesity led directly to the epidemic of pre-diabetes and diabetes that came about 10 years later because there is a very tight relationship between obesity and type 2 diabetes.
Question 2: Many men don’t think about their metabolic health until they receive a diagnosis. What are some early warning signs that men should be paying closer attention to?
The easiest measure is the waist to height ratio, which indicates increased abdominal (visceral) fat. Ideally your waist should be 50% or less of your height. So, if you a 5 foot 10 inches tall (70 inches), then your waist should be 35 inches or less.
High blood pressure is also an easily measured marker which is often, but not always related to poor metabolic health.
Question 3: How are diet and lifestyle habits connected to long-term health outcomes, and what are some practical changes men can make to improve their metabolic health?
Diet and lifestyle are directly linked to markers such as obesity and type 2 diabetes and fatty liver, which all impact long term health outcomes like cardiovascular disease and cancer.
Some practical changes include reducing ultra-processed foods, reducing refined carbohydrates, reducing sugar intake, making sure that you have a daily fasting period.
Question 4: What are some of the most common misconceptions you encounter around nutrition, weight management, and diabetes prevention?
The most common misconception is that increased calorie intake alone leads to obesity. That’s simply not true. The types of calories you eat also is hugely important. Weight gain is determined by the hormones of our body telling us to gain weight, and insulin is a major reason for that. Eating 500 calories of broccoli stimulates completely different hormones than 500 calories of brownies. Brownies spike insulin very high and broccoli does not, so the bottom line is that brownies are more fattening than broccoli. Which seems perfectly reasonable.
But it means that the constant exhortations that ‘a calorie is a calorie’ are completely wrong. You need to pay attention to the foods that you are eating, how much you are eating and why. To dumb it down to Calories In Calories Out is a massive disservice to the community because that implies that you could eat ice cream for dinner and not be worried about weight gain.
Question 5: If there was one message you could share with Canadian men about taking a more proactive approach to their health and wellbeing, what would it be?
Metabolic health, which is related to weight management is the single largest modifiable risk factor for cardiovascular disease (heart attacks and strokes) and cancer. It leads to type 2 diabetes, which is the leading cause of blindness, amputations and kidney failure. So the single best thing you can do to stay healthy is to manage your weight by changing your diet and lifestyle.