Hi. I am a researcher and dietician at the Children's Exercise and Nutrition Centre at Hamilton Health Sciences. The clinic has been running since 1983, and I've been with the clinic for ten years. I want to present today some of the research I've done with pediatric obesity and nutrition.
The first study I want to highlight is one in which I had the question: is it dietary energy or fat that contributes most to juvenile obesity? This study was published in the International Journal of Obesity in 2002. I had 181 children in the study; half were obese and half were not obese. The methods I used were a dietary history, an activity interview, and I measured body fat with bioelectrical impedance.
The result I found was that it was not fat, protein, or carbohydrate that contributed most to obesity; it was actually the calories in the diet—the calories they were consuming and then the calories they were expending in energy out.
My recommendation is that we should shift our focus right away from fat and carbohydrate to focus on total calories.
In the next study I wanted to know what foods or food groups contribute most to obesity. This was published in the Journal of the American College of Nutrition in 2003. The method I used here was the food frequency questionnaire. I was looking at what foods they consume—looking more at junk foods such as cookies, granola bars, cakes, chips, and those kind of foods.
I found interesting results. I actually didn't find that junk food was different between the obese and the non-obese groups, except that chips were consumed more by obese children. But each of the foods individually and as a whole were not different.
What I found to be the biggest difference was eating out: the obese families were consuming more foods outside the home than the non-obese. The second biggest contributor was sweet drinks. This is what I call pop, iced tea, Kool-aids, Poweraids, Utopias—all those kinds of drinks. The obese had a higher sugar intake.
My recommendation from this study was that we really need to stress the harm of eating out and of sweet drinks.
In the next part of the study I wanted to look at the actual food groups. I had some surprising results here. I found that fruit and vegetables were not different between the groups. They were low in both groups, but they were consuming equal quantities of fruits and vegetables. It was the same for milk and milk products.
What I did find with the obese was that the grains and meat group were significantly greater in the obese, and interestingly this was correlated with eating out. That would be your hamburgers, your fried chicken.
My recommendation is that when eating out and shopping we need to target healthier foods. We need to target foods that are actually healthier. To give some examples, if we're going to provide apple slices but are going to put a caramel dip with it, then we're not decreasing the sugar intake. Or if we're going to recommend submarines, which are high in grain products, that's not going to help in reducing obesity.
The next question I wanted to look at was nutrient inadequacies. If the children are consuming very high-calorie and high-fat diets, are they meeting all their nutrient needs? This was published in the Canadian Journal of Dietetic Practice and Research in 2005. I had 256 children in the study, of whom 156 were obese, and I used a dietary history method to analyze their diets. What I found was that on average the children were meeting their nutrient needs, but if I looked at the percentage of children meeting their needs, I found some problems.
I found that 81% were not meeting their vitamin E needs—vitamin E is rich in healthy oils and nuts—55% were not meeting their calcium need, and 46% were not meeting the requirement for vitamin D, which is found in milk products.
My recommendation is that we have to focus on increasing healthy fats in the diet and milk and milk products. We're doing a good job with peanut allergies, but we're not stressing the value of peanuts in terms of healthy oils. Another example is, if we're removing trans fat from the diet but are replacing it with another saturated fat like palm and palm kernel oil, again we're not increasing the healthy fat.
In the next study I looked at, which was published in Eating Behaviours in 2005, I wanted to know whether obese children gain weight at different times throughout the year. I had 73 obese youth in the study, and I was looking at the changes in percent of ideal body weight over one year at two-month intervals. I found some surprising results that are quite opposite to what we see in adults. We tend to gain weight in winter, but children lost weight throughout the year, but in July and August they gained the most weight. In November and December they lost weight, but not as much, probably because of Hallowe'en and Christmastime.
My recommendation from this study is that we have to target our education prior to holiday times such as the summer and we have to promote healthy alternatives. If they're barbecuing, what are they barbecuing? What are they doing with popsicles , freezies, sweet drinks, ice cream, and those kinds of foods?
A final study I wanted to highlight was one that I haven't published yet, but this was done looking at the consequences of obesity. I was wondering if obese youth have some bloodwork abnormalities.
I had 73 obese youth in the study and I found some surprising results. I looked at their cholesterol, triglycerides, good and bad cholesterol, sugar, insulin, blood pressure, and what I found is that 76% had one cardiovascular risk factor, so these are children who are already moving on to heart disease. And 25% had impaired glucose tolerance, so they are heading to diabetes. This was also seen in a study by Sinha in 2002, and I just quote that because mine is not published yet, but it's also showing that 25% of 4-year-olds to 11-year-olds have impaired glucose tolerance.
Although I said to focus on total calories for obesity, my recommendation is that we also need to focus on the diseases associated with obesity and target fat and sugar.
In summary, my recommendations are that we educate about and provide products that are lower in calories, sugar and saturated fat, that are nutrient-dense, and that contain a healthy fat. As well, we need to look at targeting our education at certain times of the year.
Thank you.