Thanks, Mr. Casey.
Thanks for allowing the group to have a look at the graphs; otherwise, my talk won't make a lot of sense. Hopefully it will otherwise.
I'm Dr. Tom Warshawski. I'm a consultant pediatrician working in the trenches with children and youth in British Columbia. I'm also the chair of the Childhood Obesity Foundation and the chair of the Stop Marketing to Kids Coalition, which is a coalition of NGOs from across Canada. It represents all of the major health-oriented NGOs, including the Heart and Stroke Foundation, Dietitians of Canada, Diabetes Canada, Canadian Cancer Society, Food Secure Canada, and the Canadian Medical Association, all of which have come together over the last four or five years because we feel that this issue is so very important.
I'm going to make a few points and then go to the graphs so that I can show you graphically what this is all about.
The number one point I want to make is that an elevated BMI, or obesity, is strongly associated with adverse health outcomes. They range from type 2 diabetes to heart disease, cancer, stroke, and hypertension.
Almost all excessive weight gain is due to dietary factors. It's not an issue of inadequate physical activity. The food industry has attempted to deflect the issue to being one of inadequate exercise. That's simply not supported by the evidence.
The third thing I want to say is that the ill health associated with an elevated BMI is not due simply to the fat mass. Fat is a metabolically active tissue. It secretes cytokines, which have actions at distal organs, but irrespective of your body weight, if you're eating the wrong types of foods, you raise the risk of diabetes, heart disease, and cancer. It's not simply linked with obesity.
It's not that we have to worry only about that 30% of kids or that 60% of adults are overweight and obese. Food is very important, so much so that the global burden of disease estimates that diet-related disease now kills more Canadians than smoking. It's not that smoking is so much better, there's just less of it right now. Smoking is decreasing, and we have an increasing burden due to dietary factors.
Excessive weight gain in children and youth is important not just because of the long-term effects in adulthood, but it's important to children and youth in and of themselves. It's associated with joint problems from carrying this extra weight. It's associated with asthma. Those cytokines, which I talked about, that fat cells produce also work in the lung to trigger asthma and sleep apnea. Mental health issues, both bidirectional anxiety and depression, can cause overweight and obesity or are associated with it, but also, overweight and obesity cause those problems in children and youth.
We are seeing adverse metabolic effects, such as high blood lipids, hypertension, and impaired glucose regulation, in preschoolers who are overweight and obese. A study in Italy looking at overweight and obese preschoolers showed that one-third had some adverse metabolic effect.
When we look at Canadian data on children who are overweight and obese between the ages of 6 and 17, one-third or more had adverse metabolic effects. We are seeing an epidemic of the metabolic syndrome. Some 3% of Canadian adolescents have metabolic syndrome, which has lifelong ramifications. It can also affect cognition in adolescents.
These are big problems right here and now.
To illustrate the effects of poor diet, I'm going to show you the graph on growth charts. There are a couple of utilities there to show in the growth charts just how it's put in place or, when we talk about childhood obesity, what it means. It's defined by growth centile. We look at what the overweight range is for adults. A BMI between 25 to 30 is overweight; above 30 is obese.
If we look at this particular case of Zachary, whom I first saw at age 10 for his asthma, things are going relatively well. His parents divorced. Things did not go so well; diet went down the tubes. Dad was busy trying to manage everything. Mom left the province. He began to eat a lot of junk food.
What you see is that his height continued on its normal trajectory, because that's genetically endowed, and his weight began to go up, up, up. What you see on the next page is the dramatic increase in his BMI. This was not due to a lack of exercise. It was strictly due to what he was eating.
This isn't just Zachary. This represents 30% of children and youth across Canada.
I read the riot act to Zachary and his parents, and Zachary stormed out of the office in tears because I said he couldn't drink sugary drinks anymore—no juice, no pop, and no more processed foods. To their credit, they made these changes; his weight stabilized, and the BMI dropped. That's very hard for a family to do.
People say, “Well, isn't this the family's role?” When you look at families, in 60% of families, both parents are working, and 15% of families are run by single parents. In 15%, the parents have low literacy, and 15% are recent immigrants; 10% have low income; 10% have mental health issues. The average family, then, is struggling; they're just trying to get by. We cannot create a milieu in which these children and these families can be exploited.
What I also want to talk about is the fact that we know what constitute healthy and unhealthy foods. I have two diagrams that I want to show you. The one with the coloured arrows is from Mozaffarian, in Circulation. This is a compendium of best practices from 2016. The blue area shows the foods that are clearly beneficial in terms of cardiometabolic health, obesity, cancer, and hypertension. They are fruits, nuts, fish, vegetables, vegetable oils, whole grains, beans, and yogourt, almost none of which are advertised to anybody, never mind children and youth.
The ones that are clearly harmful or unhealthy are the refined grains, starches, sugars, processed meat, and high-sodium foods. Industrial trans fat will no longer be a problem because it's being expunged from the food supply. These foods are the ones that are heavily marketed to children and youth, and they are harmful. They're harmful now, and they're going to be harmful into the future.
It seems only reasonable that foods with clear benefits should be marketed to children and youth. Appendix 4 has data from Canada. This is from Mary L’Abbé's shop at the University of Toronto, which is looking at the association of various foods with obesity in Canadian adults. The issues are the same. The same foods are associated with overweight and obesity in adults, and it is the same foods that are preventing overweight and obesity. You should be eating the fruits, the vegetables, the yogourt, and the whole grains. You should be avoiding the fast foods, carbonated drinks, refined grains, solid fats, and processed meats, which are the ones that are being marketed to children and youth. They're also being marketed to adults.
This is the association. When you look at someone's overweight and obesity and ask them what they've eaten, you flip that around and you give dietary advice to people. If you can implement that advice, and if people take that advice, you get an improvement in weight status. A very recent study just came out in JAMA, in February 2018, from Charles Gardner at Stanford. With 600 adults, they were comparing a low-carb, high-fat diet to a high-carb, low-fat diet. In fact, they found that they were equally as effective as long as people ate healthy.
Eating healthy had four major components. One, cut out all the sugars: sugary drinks and foods with added sugars. In Canada, 66% of the processed food has added sugars. As well, cut out the processed foods and the refined grains. Also, diminish the fast-food intake. Last, cook and eat at home and increase the vegetable intake. When people could follow these rules, regardless of whether it was high fat or low fat, 75% lost weight. They improved their blood pressure and their metabolic parameters. A third of them went from having metabolic syndrome to no longer having metabolic syndrome.
We know what constitutes a healthy diet, and we know what Health Canada has to do to explain that with understandable daily values.
Other points I want to make are around the issue of children and children's vulnerability. It's intuitively obvious that someone under the age of five who believes in the Easter bunny can be manipulated by marketing. It's less intuitively obvious how manipulable or vulnerable teens are. Towards that end, I want to give you a three-minute talk on cognitive neuroscience. This is condensed, of course. It's appendix 5.
The part of the brain that's responsible for logical thought, for reasoning, is the prefrontal cortex. It develops in a slow, linear fashion from birth up until age 25. It's constantly evolving. As that's evolving, however, puberty intercedes. Those of us who have teenagers or who have been teenagers understand that very real behavioural changes occur. These are hard-wired changes. They are the result of the surge in testosterone and in estrogen, which cause brain changes.
What our diagram shows is the ventral striatum, the area at the base of the brain that is responsible for reward seeking and for discounting risks. That gets a huge surge in activity with puberty, which diminishes over time. That's why Red Bull has such a great appeal for kids and teens; when they see these guys sailing on their mountain bikes over these castles, they ask what could go wrong.
Another area that gets a big surge is the area of the amygdala and the hippocampus. These are the emotional centres. They actually grow in size with puberty. This has been documented by MRI. Associated with that is an increased role of emotion in decision-making. The beverage companies in particular...Coca-Cola is very good at tweaking those strings in their advertising. These ads are aimed at teens. They're not aimed at younger kids.
The other area that is important is that of the diffuse cortical changes in the temporal lobes. These are the areas responsible for social affiliation. There is a natural tendency for teens to shift their affiliation from their parents and adults to other teens. This type of behaviour goes across all mammalian species. It does have an evolutionary role, because it triggers the individual to seek novelty, to take risks, and to expand their territory.
What happens in these kids is really a control imbalance. If you look our last graph in appendix 6, what you see is a gradual increase in prefrontal cortex function, which is moving along merrily. That's why your 10-year-old thinks better than your five-year-old.