I picked up our copy of The Wall Street Journal from the driveway this morning, and was startled to see a front-page teaser "Why Evolution is Making Us Fatter." I immediately turned to the Personal Journal section which had A Health and Wellness theme today and read the article which actually was titled "Obesity? Big Feet? Blame Darwin" with a subtitle "Evolution Helped Humans Have Children and Survive, but It Also Led to Modern-day Maladies, Scientists Say."
Many modern scientists think we're a collection of compromises arising from our predecessors' adaptation to changing environments. The obesity related sections were certainly there, but they were a minority among paragraphs on the evolution of lactose tolerance, skin color, immunity and brain size, among other topics. But I wanted to concentrate on the weight-related arena. The first such mentioned the move from hunter-gatherer status to agriculturalists roughly 10,000 years ago and the subsequent dietary shift to more carbohydrates leading to a decrease in average population height and more obesity. Most populations have adapted over the centuries to the new foods; those that made this change more recently were said to have higher rates of obesity and diabetes type 2.
Then there is the hormone leptin, our body's signal to stop eating. I found British Medical Journal articles dated 1996 on its discovery and chemistry, but the initial promise that it could be used to help the obese lose weight was stymied by the finding that obese humans usually develop leptin resistance. I also found a current website from a clinical nutritionist advertising the "leptin diet," a set of five eating rules that mostly made common sense. The first three: never eat after dinner; eat three meals a day and don't snack; don't eat big meals are all concepts that I'd agree with: the other two: eat a high-protein breakfast and decrease the amount of carbs eaten, I'd modify. I've moved away from eating white bread, white rice and white potatoes in excess, but complex carbohydrates are certainly still on my list of good foods to eat. And I have decreased my overall intake of red meat as a source of protein, so no more breakfast steaks.
Overall leptin seems to play an important role in our bodies. There was a 2009 article on the website www.medicalnewstoday.com which reported that there were several FDA-approved oral drugs that can sensitize the brain to leptin. Investigators at Boston's Children's Hospital were working toward clinical trials.
I need to see more research before to be convinced that leptin levels markedly decrease when you diet and therefore you burn less of ingested calories and regain weight. And, for now, I'm not at all interested in the websites which offered "pro-biotic and herbal cleansing" products to overcome leptin resistance.