Saturday, November 18, 2006

A Match NOT Made in Heaven

Back in April my concerns regarding calories and the draft Food Guide were published in the Canadian Medical Association Journal (CMAJ). This wasn't the first time I had voiced my concerns, the first time was at a Think Tank on obesity where I had the opportunity to lunch with Health Canada officials. At that time my concerns were dismissed seemingly out of hand, but within days of publication in the CMAJ, Health Canada called and asked for a sit down.

As I mentioned in my earlier post, Consultation, What Consultation, to me at least it seemed that Health Canada certainly wanted to hear me, but did not especially want to actually listen to me. They spent most of the meeting trying to explain the fact that they had done caloric modeling and that their diet models had fewer calories than Shawna, our dietitian, had predicted.

Counting calories is actually a pretty easy thing to do - there's really not a lot of room for error. There are many online and print resources for tracking calories, and as it turns out, it was due to Shawna and Health Canada's choices of resources (and Health Canada's refusal to acknowledge "Other" foods - will get to that tomorrow) that led to their differences in numbers.

Shawna used real-world resources. She used actual products' Nutrition Facts labels and the 2006 version of the Calorie King Calorie, Fat and Carbohydrate Counter. Health Canada on the other hand used the almost a decade old 1997 Nutrient File.

So let me ask you a question. If you were counting calories, but your calorie database was out-of-date do you think you'd be counting accurately?

Here's another question, if your calorie database grossly underestimated the number of calories in foods, do you think that maybe, even if you were keeping track, you'd be eating more calories than you thought?

Well guess what, the 1997 Nutrient File is terribly out-of-date and does indeed grossly underestimate the number of calories in foods, and that's one of the reasons why Health Canada came up with much lower numbers than Shawna did when calculating the calories following the Food Guide would lead you to consume.

To explain what I mean, I'll use an example. Before my House of Commons testimony I went into my local supermarket and looked at their bread section. While the 1997 Nutrient File and consequently the Food Guide conclude that a slice of multi grain bread weighs 26g and contains 65 calories, that was true with only 1 of the 31 total loaves available for sale. Of the remaining loaves, over 2/3 weighed 60% more than expected by Canada’s Food Guide. Two of the most popular multi grain loaves, Dempster's Multigrain and Country Harvest 12 grain each had slices that weighed 45grams and contained 130 and 135 calories per slice respectively or DOUBLE what the 1997 Nutrient File says they should.

Remember, with regard to weight, its currency is calories. If for one year the only thing I did differently was eat one sandwich with Dempster's or Country Harvest bread in place of the non-existent 1997 Nutrient File bread, I might gain 13.5lbs more than Health Canada would predict. Why? Calories. Don't believe me, here's the calculation:

(260cals Dempster's - 130cals Nutrient file) = 130 cals per day more

130 cals per day x 365 days per year = 47,450 cals extra per year

47,450 extra cals per year / 3,500 cals per pound = 13.55lbs
And of course it's not just bread. The 1997 Nutrient Files says a commercial blueberry muffin has 197 calories. Tim Horton's says it has 340 calories. It's even off on fruits and vegetables because the average sizes have grown. I weighed a potato at home and it was 75% larger than the ones listed in the 1997 Nutrient File and to my eyes, it looked like a pretty average sized potato.

The thing that's the most remarkable is that even if you take Health Canada's calorie models as accurate, they still recommend far too many calories. Health Canada informed me that a 19-50 year old woman following the new Food Guide would consume 1,750 calories daily.

Using that number let's take a pretty typical hypothetical Canadian - a 50 year old, sedentary, 5ft 4 woman. According to the Mifflin St-Jeor equation, currently the best equation we've got to predict calorie requirements, if she were to eat 1,750 calories daily that would lead her to a weight of 188lbs and a medical diagnosis of obesity with a body mass index of 32 (if you want to calculate this yourself, I used an exercise coefficient of 1.2).

So does the Food Guide contribute to obesity rates in Canada?

If it's followed it sure does - it recommends far too many calories. Of course whether or not the Food Guide's followed is a tough question to answer since formal studies have not been done to determine the percentage of the population who try to tailor their diets to meet the Guide's recommendations.

That being said, below is a graph from Statistics Canada detailing the average number of calories consumed by Canadians. Notice what starts to happen in 1992 when the then new Food Guide came out.


So what did the 1992 Food Guide recommend? Well it recommended that we consume 25% more meat, 50% more milk products, 67% more fruit and vegetables, and much to the delight of grain farmers I'm sure, 112% more grain products than the 1982 Guide.

Health Canada at this point usually likes to try to make me look ridiculous by trying to state that I place the blame for Canadian obesity rates solely on Canada's Food Guide. So I'll be very clear here, I'm not putting all of the blame of Canada's rising obesity rates on the Food Guide - but to pretend that it has not or could not be a factor would be a gross oversight given the dramatic increase in per capita calorie consumption that began in 1992, the dramatic rise in obesity rates in Canada since 1992, the fact that according to Statistics Canada, obesity rates between 1978-1992 had remained steady and the fact that the Food Guide recommends a ridiculously large amount of food.

Even according to Health Canada themselves, the 1992 Food Guide provided incredible amounts of food,
"If you follow the Food Guide, you will get between 1800 and 3200 Calories each day."
Take that same 5 ft 4 sedentary 50 year old and give her 2500 calories a day and given enough time, she could end up over 300lbs.

And you should know, that 2500 calories does not include "Other" foods, which Health Canada in their seemingly infinite wisdom, have simply decided to ignore in the coming Food Guide.

Tomorrow: Oh, and you Can't have Ketchup - How Health Canada has ignored 25% of your dietary energy intake.

Yesterday: Drink Lots and Lots of Milk - Don't worry about all that research that suggests that in fact it might not be so good for you.

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2 comments:

  1. Just a short note too, that Tim Hortons' muffins and other product calories are based on ideal laboratory-like conditions. I worked at a few Tim's, and the bakers weren't exactly sparing with the extra shortning (made it easier to clean the pans).
    I'm sure its a similar case with other establishments.

    Thanks for the blog. I'm trying to conquer my own near-obesity and the misinformation out there sure doesn't make it easy.

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  2. Anonymous5:32 pm

    All I can say is Thank you. As someone very keenly interested in nutrition its great to have your excellent research as a back up.

    ReplyDelete