By John Kruse
My last post was a discussion about the economic cost of obesity and overweight in this country. Essentially, I was pointing out that obesity is going to continue to be a major obstacle no matter what we do in an effort to save money in this country with health care reform.
I was excited when a friend posted the article on her Facebook wall. That is until I was accused of fashionably blaming fat people. Needless to say, I felt compelled to defend myself and pointed out that I was trying to prevent obesity in the first place. After all, I had written that education is the only way to prevent obesity.
I was shocked when this same person asked where the proof is that obesity causes the diseases that I had listed as being associated with obesity (diabetes, hypertension, cardiovascular disease etc). I was shocked because I was under the impression that pretty much every adult who at least watches some television would know that obesity causes disease. I told her that the evidence is overwhelming and that the medical community would consider it common knowledge. She persisted and stated that associated doesn’t mean cause. And essentially brought up the whole statistics thing about correlation not meaning causation. This statistical argument is sometimes a good one and I like to use it myself.
In an attempt to convince this critic, I felt like I should send her an article that discussed the diseases. I was careful to choose one with peer-reviewed references. Amazingly, she persisted.
Finally, I realized that I hadn’t really thought about the underlying cause in a while. The more I thought about it, the more I realized that this is information that I just take for granted. I really struggled to come up with a really good answer from the top of my head. Consequently, I consulted a few text books and found that most of them just glossed over the topic and didn’t really explain how obesity and overweight cause these diseases. Even my biochemistry book glossed over the topic.
This is why content knowledge is so very important and I was reminded of a few colleagues who always remind me that content knowledge is the number one predictor of teacher effectiveness. Don’t we always have that pesky student who keeps asking those questions that push us into the cobwebs of something we learned long ago? Or even worse, into something we never learned? In this case, it was an adult. As an educator, I felt like I owed her an answer. Not only did I owe her an answer, I began to feel like I had to save face for our profession. Physical educators often times get characterized as dumb jocks and I was determined to not let this be the case in a public forum like Facebook.
Eventually, I found the answer I was looking for and I really hope you’ve made it this far. I’m about to give you the content knowledge to answer this question and I hope you find it useful someday. We owe it to our students and we owe it to our profession.
Weight loss is generally accompanied by an improvement in blood lipid and lipoprotein profile and an increase in the sensitivity of peripheral tissues (muscle, adipose, and liver) to action of insulin. On the other hand, a gain in body weight may result in an increase in total serum cholesterol and LDL cholesterol, an elevation in triglycerides, and a decrease in HDL cholesterol. An increase in body weight is also followed by a progressive deterioration of the response of peripheral tissues to insulin, which leads to an increase in insulin secretion by the pancreas, hyperinsulinemia, and a series of other metabolic events (Sasaki et al. 1987; Gutin and Owens 1999).
Growth, Maturation, and Physical Activity by Malin, Bouchard & Bar-Or
So as you can see, obesity and overweight does influence our health. It does have something to do with our good and bad cholesterol. We know that cholesterol is part of the cardiovascular health equation. We also see that weight gain influences insulin. As we know, insulin is part of the diabetes equation. Case solved!
I really hope I’ve convinced you of the importance of content knowledge. Always keep reading and always keep adding to your personal library. As I stated before, we owe it to our students and to our profession.