The "Fat Head" Movie

Dear Tom,

I'm honored that you read and made a comment on my review of your outstanding movie! Thank you so much.

As I wrote in my review, what disturbed me the most was Professor Oliver's statement that it's best for our health to be at the high end of normal or even a little overweight. I had read his book Fat Politics before and even mentioned it in one of my previous articles here, but had forgotten it (probably because it was a message that I didn't want to hear!). I have now asked my library to get it for me again so I can re-read it.

But the problem probably can't be cancer. As I wrote here in "Another Reason to Lose Weight" in my review of a huge new study of the World Cancer Research Fund and the American Institute for Cancer Research, "Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective," they came to definitive conclusions about the link between weight and "Be as lean as possible within the normal range of body weight."

My review of your movie also asked my readers to help me find the primary research on this important question. Already one reader has now directed me to a comprehensive review of the sort of papers that Professor Oliver seems to have relied on. This review, "Weight Loss and Mortality: What Does the Evidence Show?" by Meir Stampfer, a professor of epidemiology and nutrition at the Harvard School of Public Health, concludes that, "Given the well-known adverse metabolic consequences of overweight and obesity, the strong links with cardiovascular disease and several other serious illnesses, and the absence of any plausible adverse biologic consequences of maintaining normal weight (BMI 19 to 25), it seems prudent to continue advising adults to seek to maintain a weight within that range. The results from Kaprio et al, although they raise questions about the effects of weight loss, do not cast serious doubt on that advice."

Nothing is ever "the last word" in scientific research, of course. And I agree with you that the BMI is an imperfect measurement (as I acknowledged in my second book, Losing Weight with Your Diabetes Medication), but for now I am going to continue to maintain my weight at about 152 pounds on my 6' 2.5" frame. That is a BMI of 19.3.

Best regards,

David

Wow, David, you really are lean!  (Healthy too, I presume.)

My guess is that BMI doesn't matter so much as blood sugar.  Since people with high blood sugar are morely likely to become both insulin-resistant and obese, a higher BMI could be associated with health problems without being the actual cause. 

My BMI and body-fat percentage are consistently higher than the recommended norms, but my lipids are excellent and my blood sugar is generally around 80.  By contrast, my father-in-law is as lean now as when he was a teenager, yet he has type II diabetes. 

But overall, I'd guess that more insulin-resistant people are fat that not.  I certainly wouldn't recommend that anyone with a low BMI try to become fatter.

I enjoy keeping up on the science, so if you come across interesting research on the topic and don't mind sharing it, please send it along.  I believe you have my email address from my posts.

Again, thanks for making people aware of "Fat Head."  You weren't alone in worrying that it would be a fast-food love-fest.  Mike Eades was hesistant to be involved until he realized I was promoting personal responsibility, not the wonders of fast food.

Best,

Tom

Dear Tom,

I am indeed more healthy than I have ever been in my 73 years! I don't take any prescription medications for diabetes or for anything else. My A1C is about 5.5 on my very low-carb diet and lots of exercise, mostly hiking.

I do have your email address and will keep in touch. Do you have plans for another movie or other project related to nutrition?

Best regards,

David

Hi,

I'm intrigued by another piece of very bad science...the continued use of BMI as a measure of obesity.

Even an average 12 year old can tell you that as you double an object's size you cube it's weight, yet BMI relates size (i.e. height) squared to weight.(BMI = weight divided by height squared)  

This mathematical inaccuracy means that BMI produces lower figures for shorter people and higher figures for taller people. That''s why BMI doesn't work fo children or very tall people. ie. if you're short you'll be more obese than your BMI indicates, and if you're tall you'll be less obese than your BMI indicates. As average heights increase, average BMI will go up, for the same level of actual obesity. Perhaps this explains some aspects of the 'obesity epeidemic'

How the medical profession can continue to use (as they have done for 100 years now!) a formula based on a mathematical fallacy astounds me. What I find even more astounding is that when I point this out to doctors they agree with the logic of using a cubed relationship instead of a squared one, but still make excuses for using BMI as an accurate measure! 

It all goes to show that sometimes science takes a back seat to medical 'opinion'

To simply resolve this issue all that's required is to use an  'Adjusted' BMI or ABMI, using an average height (an average in the 1950's to relate older BMI figures to current ones) of say 1.70m in the formula : ABMI= Weight divided by height cubed x1.70 (for metric users like me)

Doing this provides an 'A' BMI that works for short, tall, even children, producing far more representative figures.

The validty of this approach can be seen by taking an extreme example...take a 90kg person 1.8m tall, BMI =27.7 

Now double their proportions exactly, their height will be 3.6m, their weight 720kg by simple geometry)  Their obesity levels are the same, as we've just scaled proportions. Their BMI is now 55!

Or halve their proportions, their height will be 90cm their weight (by geometry again) 11.25kg -Same obesity level but their BMI is now 13.8!

Exactly the same levels of obesity, yet three widely differtent BMI's.

Using ABMI their ABMI's for these three cases would be 26.2, 26.2 and 26.2!

Point proved? The only issue is whether 1.7 is the right correcting factor, I lean more towards about 1.65 as the best factor, as current BMI's already have a biased effect on taller people, and I beleive 1.65 makes a good correction for that.

Food for thought?

Dear Ted,

Thanks for providing the link to that study. It is also worth our study.

Best regards,

David

Hi, Frankenduf --

I agree that abdominal fat is associated with diabetes and metabolic syndrome (that's what epidemiology gives us: associations), but I don't believe it's a scientific certaintity yet that abdominal fat is the cause.  It could be that abdominal fat and diabetes and heart disease all share the same root cause and are therefore associated.

I think high blood sugar is likely a root cause of all three.  I became fat as an adolescent, when I was eating lots of sugary cereals and other starches.  That no doubt led to high blood sugar, high insulin, and the resulting fat storage.  After some years as a relatively lean teen and young adult, I fattened up again when I flirted with vegetarianism as an adult and lived on pasta and potatoes.

I now have more abdominal fat than the medical guidelines would recommend, but I eat very few carbohydrates and have no signs of diabetes or metabolic syndrome.  My HDL is consistently around 62, as are my triglycerides.  My blood sugar is at the low end of normal.

If I'd continued living on a high-carb diet, I'm sure I'd be significantly fatter and on my way to developing metabolic disorders.  But the extra weight and the disorders would both be driven by blood sugar, not abdominal fat per se.

I don't know if you've seen the film, but my real beef with the BMI stats is that they're used to jack up the obesity statistics.  Sure, Arnold and Mel Gibson and Michael Jordan are healthy in spite of having BMIs of over 30 because, as you point out, they're in great shape.  But they're still counted as obese Americans, and that is how we get the figure that 1/4 of all Americans are obese.  Eric Oliver, who appears in my film, is quite obviously lean, but he's counted as overweight because his BMI is over 25. 

Obesity is a real problem, but we're exaggerating it.  And by focusing so single-mindedly on BMI and weight, we're losing sight of thin people who develop metabolic disorders without becoming fat.  I already mentioned my father-in-law as an example.  Because he was lean and leanness is considered synonymous with good health, he didn't think he had a problem.  Even after he was diagnosed, he was in denial until he had a blurred-vision episode.

All that being said, if you are an apple-shaped man, you should heed the warning sign and start restricting carbohydrates.  Depending on hereditary factors, even a very low-carb diet may not make you lean, but it'll improve your health -- and probably bring down your BMI in the process.

Best,

Tom

Dear Chris,

Using RSS with Google Reader (and Bloglines, etc.) is a good way to keep up. But you do have to remember to read your reader -- you have to remember to go to it every once in a while. Technically, this is called pull technology.

Much better is push technology, i.e. to get an automatic email in your inbox. Few sites offer this -- but Health Central is one of those few.

The Health Central Network will now notify you by email of new articles (SharePosts) by me or anyone who posts at HealthCentral.com. Just click on "Subscribe" at the top of each of my articles or on my "Profile" page.

Best regards,

David

David,

That advise on receiving email updates might be good for some people, hopefully somebody takes that advice...

Unfortunately, I am trying to cut down on the emails in my inbox! I do check my Google Reader several times a day though, probably too much. I was even checking it yesterday in class.

Dear Chris,

I understand. But I think you should be taking a more interesting class!

Best regards,

David

Oh David, how I wish I could be in a more interesting class.

Our first class on Mondays is pretty intense, it's where we learn all the pathophysiology for disease processes, as well as proper nursing interventions, medical interventions, etc. But this class is 3 hours long.

Then we have lunch, and go back for another class that is 2 hours long. It's not as difficult, and while it is just as important in a different way, people pretty much consider it a blow-off class. After sitting around for 3 hours in a hard class, then eating lunch, I'm not sure I could pay attention if I wanted to.

Dear Melissa,

Actually, the research continues to show that people with a low BMI live longer than those with a higher BMI. Please see http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1160586#pmed-0020181-b5

Best regards,

David