Is obesity responsible for the recent rise in youth cancer?

Last week the Canadian Cancer Society released its report Canadian Cancer Statistics 2009. In it they report that between 1996 and 2005 the incidence of cancer among Canadian 15 to 29 year olds rose 0.8% per year in males and 1.4% per year in females.

So the question of course is why? Why are cancer rates rising?

While I don't want to jump on the bandwagon of blaming obesity for all of society's woes certainly given the established link between obesity and cancer in adults it doesn't seem a stretch to me to wonder if it's the rising weight of Canadian youth that's leading to this rapid rise in cancer.

The Canadian Cancer Society may think weight's possible culprit too given that along with the obvious recommendations of "not smoking", "eating a healthy diet", "exercising" and "wear sunscreen", is "maintaining a healthy body weight".

I imagine time will tell as data from surveys that include variables such as weight may help shed some light on this disturbing trend.

Newsflash - Weight's not good for your health!

Published this week in the Lancet.

A meta-analysis summarizing 57 studies on the effects of BMI on mortality.

900,000 subjects in total and they excluded deaths in the first 5 years to eliminate the bias of death from subjects already dying (and consequently in many cases often quite skinny due to the wasting associated with many chronic illnesses).

The results?

All-cause mortality was lowest among those with BMIs in from 22.5 to 25.

Above a BMI of 25, every 5-unit increase in BMI translated to a:

30% increased risk for all-cause mortality;

40% higher risk for death from heart disease or stroke;

60% to 120% increase in renal, hepatic, or diabetic mortality;

10% increased risk for cancer-related deaths.

I wonder how folks who make their livings as contrarians to the risks of weight are going to spin this one?

Canada - Lighter than America

Not a huge surprise, but thanks to David Eaves (of the interesting blog Eaves.ca) we can see that if obesity rates in Canadian Provinces were ranked alongside American States, our Provinces place first through fifth.

Before you get too excited, Nunavut and the North-West Territories fall into 30th place.

Regardless of how you want to look at the data one thing's for sure - North America is one big continent and it's only getting bigger.

[Hat tip to Mark Schrimsher from CalorieLab who also created the original map that David worked off of]

Attention Government of Guyana

Anyone out there know anyone high up in the Guyanese government? They need some help.

According to the Guyanese Minister of Health, Dr. Leslie Ramsammy, obesity is becoming a problem over there. An article in the Stabroek News has Dr. Ramsammy quoted regarding their new crisis as well as provides some context for it.

Context wise, turns out just as in North America, it is abnormal in Guyana for someone to have a healthy body weight with 53% of the population being overweight or obese. The survey also revealed that in urban areas 68% of the populace ate out daily.

Their survey also looked at calories. Apparently the Guyanese' average daily caloric intake is 2,849, up from 2,269 in 1963.

Perhaps not so surprisingly given what seems to be a global culture of fear surrounding the talk of calories the Guyanese government's response to their new found crisis is to ignore the calories and instead to promote two things:

1. Increased physical fitness
2. Consuming more than 400grams of fruit and vegetables daily

Um, Minister of Health Ramsammy, do you have an inkling how much exercise a person would have to do to burn the additional 600 or so Calories a day they're now consuming? That's of course also assuming that the estimates are correct, and given that 68% of your urban population eat out daily, and that restaurant food is pretty much always underestimated calorically, that's a stretch. So back to the question, 600 Calories burned = how much exercise?

Well, for mild exercise (walking, gardening etc) it'd be anywhere between 2 and 3 hours daily. Moderate exercise up to 2 hours and intense exercise between 1 and 1.5 hours daily.

Shame though that in your recommendations you've actually suggested to the population that they should strive in fact to eat more not less. Did you know that fruit had calories in it too?

If there were a way to buy obesity futures in Guyana, I'd be calling my broker as I type.

The Weight of the World

Hat tip to the web log rightsizingamerica that pointed me to this pictorial representation of global obesity rates (click it for a larger view).

The picture comes from a generally non-weight related web log entitled Wellington Grey.

If there are educators out there who want this as a poster, the graphic's designer has opened up a webshop selling them.

$20.69 for a large poster.

(Sorry for the late post - I moved on Friday and don't have an internet connection at home yet)

Do Newspaper Recipes Make you Fat?

My media scanners picked up this headline on Friday,

"Community Obesity Rates Linked To Calories From Newspaper Dessert Recipes"

and of course, I immediately closed the Citizen's food section.

All kidding aside, what the headline did do was spur me to read the actual article published in the Wisconsin Medical Journal entitled:

"Calories from Newspaper Dessert Recipes are Associated with Community Obesity Rates"

After reading the methodology and the paper, I can say that without a doubt this is the weakest article I have ever read that was actually published in a peer-reviewed medical journal.

Here are their methods:

"3 cities with populations of 400,000 or more were selected from 4 geographic areas within the United States....All recipes published in major newspapers for those cities in the last week of August 2000 were accessed....and the nutrient content for each recipe was calculated....data were entered into an Excel spreadsheet and analyzed with SPSS using linear regression and correlation."

So basically a bunch of large cities had their obesity rates plotted against one week's worth of local newspaper recipes' Caloric contents.

The authors concluded,

"In this study, we found that caloric intake of recipes published in major newspapers are correlated with community obesity rates."

The authors do admit that there are limitations to the study,

"Limitations of this study stem primarily from the correlational study design that may lead to the "ecological fallacy" where the observed correlation may be due to some underlying differences between the communities included in the study, such as demographics or health care"

Um, yah think?

Two things blow me away about this study. Firstly that any self-respecting scientist would publish correlational data based on a SINGLE week's worth of data boiling down an incredibly complex social and medial condition with dozens, if not hundreds of possible hypothetical contributors, to have cause from a single observational variable, and secondly that somehow this thing passed peer review.

[note to self, if I ever have a poorly designed study that I can't get published elsewhere maybe consider the Wisconsin Medical Journal]

This study reminds me of a story published a few months ago in the Economist where Toronto based scientist Peter Austin "proved" that those burn under the astrological sign of Sagittarius were 38% more likely to be admitted to a hospital with a broken arm. The difference between Austin's ridiculous conclusion and these authors' being that Dr. Austin purposely designed his study to promote a ridiculous result so as to call to question conclusions like the one above and highlight the need for proper study methodologies and statistical analyses.

Statistics can be incredibly misleading.

French Women DO get fat!

You may have seen this book on the bookshelves. It's been a national best seller all over the world. Unfortunately it seems, the french women, aren't reading the book (or perhaps, like 98-99% of diet books, it fails in the most important part of weight management - sustainability).

A national survey conducted annually in France show that in fact overweight and obesity rates are rising rapidly. Currently 42% of France's population over the age of 15 is either overweight or obese.

It should be pretty telling to consumers. As of today, there are over 178,285 different diet books for sale on Amazon.com. If any single one of them was dramatically better than another, doctors offices worldwide would be prescribing it. In fact in the history of medicine, there has yet to be a study the definitively proves one diet is better than another for weight loss.

In my office at the Bariatric Medical Institute, there are no prescribed diets. Every person is an individual, with different cultural backgrounds and different dietary likes and dislikes.

Here are the only two criteria that matter for diet and weightloss:

1. You eat less calories than you burn (that will help you lose the weight)
2. You like what you're eating (that will help you keep it off)

The Fat Clock

You know those clocks that count? The ones that post a real-time count of things like a country's accumulating national debt, number of people on earth, people dying of various diseases?

Well there's a new clock on the block - the Fat Clock. Using a fairly sophisticated home-made algorithm the Diet Detective website has a clock posting the running tally of the weight of all Americans. It takes into account birth rate, death rate, population age and other variables.

According to the clock, Americans are currently gaining 1,267 pounds per minute!

Dying, literally, for a Big Mac

Much to my amazement, there exists a group of individuals who vehemently deny that obesity is medically risky. They're organized, write books and blogs, and often appear on national news shows claiming that it's all a big myth perpetuated through a combination of bias and capitalism. Should any of them read this blog, I would love their viewpoint on yet another in a never-ending line of well designed medical studies that clearly demonstrate the risks of obesity.

In this weeks Journal of the American Medical Association, Kathleen McTigue et al. looked at death rates and heart disease in 90,185 women following across 40 States for an average of 7 years.

Her results were not in the least bit surprising: The heavier the patient, the higher the death rate. For those with body mass indices between 30-35 death rates increased by 18%; for those with body mass indices between 35-40 death rates increased by 49%; and for those with body mass indices greater than 40 death rates rose by more than 100%.

An easier and far less scientific experiment is for you to think to yourself how many people dramatically overweight people you know who have made it past the age of 75. Speaking for myself and including the literally thousands of patients I used to have when I was working as a GP, along with the thousand or so I saw in stroke rehab, along with my friends and family, I can only think of around 30 over-75-year olds who had BMIs greater than 40, and none of them were living easy, carefree, healthy lives - they all had significant weight related co-morbidities that made their lives very difficult.

I'm all for beating down bias against obesity, and there's no doubt that some folks with significant amounts of weight to lose will lead long healthy lives unaffected by their weights. That being said, some smokers don't die from lung cancer, but of course that doesn't make smoking any healthier.