Obviously.....

Modern medicine has given us many beliefs that we all take for granted.  In fact, I believe that we do such a good job of taking them for granted that we come to absorb them as unquestionable facts, when we should be requesting facts to make sure they are true.  Not only does medicine help us incorporate many assumptions as facts, but it shoves them at us.  What kind of assumptions?  Well, it's unhealthy to be fat.  It's good to exercise.  It's bad to smoke (this one they may have done a good job of proving).  It's unhealthy to overweight.  Salt is bad for you.  Dietary fat is bad for you.  Trans-fats are bad for you. Dietary calcium is important to prevent bone fractures.  Vitamin D levels need to be above a certain level or you should supplement your diet with exogenous/dietary Vitamin D.  It's good to take a multivitamin.  Organic food is healthier.  Pasta is fattening (from my childhood).  Pasta is part of a low-fat, healthy diet (from my teenage years).  Pasta is fattening because it's high in carbohydrates and has little nutritional value (from my carbs-are-bad adulthood). 

Do we believe most of these things?  I think most people do and I'm the skeptic.  I generally keep quiet about my skepticism because it's a game where you don't know the answer until you're dead, and if I die a young death, I don't want to give anyone the satisfactions of saying, but of course, she wouldn't take her Vitamin D, her calcium supplements, and she salted everything.  She got what she deserved.  

So with that thought, I figured I would steer you to an article in the New York Times, "In Obesity Paradox, Thinner May mean Sicker." The article starts by talking about how among people with diabetes, those who are overweight fare better than those who are not, and the same is true for people with some other illnesses.  This is not the fashionable thing to say, we all believe (myself included) that if you have risk factors, then losing weight helps you to be healthier. 

 Harriet Brown writes:

In 2005, an epidemiologist, Katherine Flegal, analyzed data from the National Health and Nutrition Examination Survey and found that the biggest risks of death were associated with being at either end of the spectrum — underweight or severely obese. The lowest mortality risks were among those in the overweight category (B.M.I.s of 25 to 30), while moderate obesity (30 to 35) offered no more risk than being in the normal-weight category.

Whatever the explanation for the obesity paradox turns out to be, most experts agree that the data cast an uncertain light on the role of body fat. “Maintaining fitness is good and maintaining low weight is good,” Dr. Lavie said. “But if you had to go off one, it looks like it’s more important to maintain your fitness than your leanness. Fitness looks a little bit more protective.”

That is a message that may take a long time to reach your family physician, however. “Paradigm shifts take time,” Ms. Bacon said. “They also take courage. Not many people are willing to challenge the weight conventions. They’re just too culturally embedded, and the risk of going against convention is too high.”

Now let me just point out that the fact that heavier people may fare better with diabetes does not necessarily mean that a thinner person with diabetes who gains weight will do better, or that any given overweight person with diabetes might not do better if he loses weight (we all know people who control their diabetes with lifestyle changes and no medications).   It may mean that gaining weight helps, or it may be that there is something intrinsically different about thin vs. heavy people with diabetes. 

Finally:

In 2007, a study of 11,000 Canadians over more than a decade found that those who were overweight had the lowest chance of dying from any cause.  

As time goes by, we get fatter, and we also live longer.  What health assumptions do you make that might be hard to forgo?