Monday, November 21, 2011

My Thoughts On Obesity

The other day in one of my classes, we began a "Weight Management" unit, which is one of my favorite aspects of nutrition.  Despite the fact that I've never had a weight problem, I find it fascinating learning about what makes people gain weight and how to lose it.  But I was quickly reminded how much I completely disagree with the conventional model.  Or maybe I'm being nice... let me rephrase that.  The conventional model is completely wrong.  Allow me to explain myself...

The conventional model of obesity is as follows:  Eat more calories than you expend and you'll gain weight.  To paraphrase my professor, it really is just a simple math equation.  And for weight loss, burn more calories than you take in and you'll lose weight. That's not the part I disagree with.  That is an established fact.  But the problem is that conventional obesity paradigm ends there.  Really?? That's it?? I'm paying for a top quality nutrition education, and we're not going to delve any deeper than that?  I would expect this in a high school health class; you don't need to bother high schoolers with the finer details that they likely wouldn't even care about.  But this is an advanced course in nutrition... I expect more than the "all you need to lose weight is a calculator" mentality.

This calories in, calories out model of obesity says that if you've gained weight, you've consumed more calories than you've burned, but it does nothing to explain why someone has consumed more than they've burned.  Imagine walking into a room full of people.  You ask someone, "Why are there so many people in this room?"  And the response you get is, "Because more people entered the room than left it."  That would be a stupid answer, something a 2nd grader might tell you when they first learn about addition and subtraction.  But that is essentially the same as telling someone they got fat because they consumed more calories than they expended.  It's obvious, but it doesn't really tell us anything about why that is the case.  While excess caloric intake causes obesity, you can go much deeper than that (that's what she said).

Tuesday, November 8, 2011

New Study: Low Cholesterol More Deadly Than High Cholesterol

I hate to say I told you so.  But I did.  Like a million times.  Yet, the fear of cholesterol continues.  What is it?  Is it the Lipitor ads?  Is it your cholesterol-phobic doctor, determined to get your cholesterol under 200 mg/dl at all cost?  Whatever it is, it's about time we stopped worrying so damn much about high cholesterol.  This new study, entitled "Is the use of cholesterol in mortality risk algorithms in clinical guidelines valid?  Ten years prospective data from the Norwegian HUNT 2 study.", shows us why.  Did anybody hear anything about this one in the media??  I didn't think so, not with a catchy title like that.  At least now the 3 people that read my blog will be aware of it.  The researchers followed 52,087 Norwegians aged 20-74 who were free of cardiovascular disease (CVD) for 10 years, then assessed the relationship of total cholesterol with total mortality, CVD mortality, and ischemic heart disease mortality (IHD).  (Just to be clear, CVD mortality signifies deaths from any disease of the cardiovascular system, while ischemic heart disease refers only to diseases involving restricted blood flow to the heart.)  Let's jump straight into the data then, shall we?  And another note:  since this study comes from Europe, the units for blood cholesterol are shown in mmol/L, rather than the mg/dL that we are used to.  The researchers classified the participants into four groups, based on their blood cholesterol.  Here are the converted unit values in mg/dL for the four groups...  <193, 193-229, 230-269, and >270

First, the least shocking data.  This graph compares the association between cholesterol levels and death from ischemic heart disease.  For the men, it looks like there's not much variation.  Deaths from heart disease rose slightly along with cholesterol levels, but nothing dramatic.  Women, on the other hand, yielded a much more interesting result.  Clearly, by a LARGE margin, cholesterol below 193 mg/dL was most predictive of death from heart disease.  All other groups, including the group with cholesterol over 270 mg/dL, showed significantly lower risk.  Yes, seriously.  On to the next graph!