Karen's Blogs
Protein and Burning Fat
As I’ve said a gazillion times, I’m fascinated by research on eating and weight. We’ve come so far scientifically since I had my food struggles decades ago and all we knew about how to fix them was based on the simplistic theory of calories in and energy out. Now we recognize how complex and complicated this subject really is.
For example, an article in Science News (1/15/11), entitled “Mice missing protein burn more fat: research suggests molecular way to rev up body’s furnace” by Tina Hesman Saey, reinforces the fact that all bodies are not created equal. Studies at the Baylor College of Medicine in Houston led by Yuxiang Sun conclude that “Mice lacking a protein that responds to the hunger-promoting hormone ghrelin burn more energy in their brown fat than other mice.” In terms of caloric expenditure, this means that brown fat is good fat, that is, rather than simply storing fat as white fat does, it actually burns it up. It does so in order to regulate body temperature in animals, including humans.
The Baylor conclusion came about through studying the affect of ghrelin on appetite and ended up answering the question of why we pack on pounds as we get older—“the amount of energy burned by brown fat decreases with age and weight.” Without getting too technical, suffice it to say that the Baylor team went on to look at the correlation of ghrelin receptors and brown fat. It turns out that “removing the ghrelin receptor causes brown fat cells to make more of a protein called UCP1…which makes the cell’s power plants less efficient and, as a result, they release more heat.” The upshot is that without UCP1, brown fat cells end up burning their own fat supply “and gobble up fat that otherwise would be stored in white fat cells.” Thus a decrease in fat leads to leanness, at least in rodents.
So, how is this news relevant to you? First, says Sun, ‘There may be more than just exercise and willpower that can keep us in shape’.” So, if you struggle with attaining or maintaining a healthy weight, this study underscores that you’re not crazy and that you may well have a different metabolism than other people who lose weight (and keep it off) more easily. Quite possibly, you have less brown fat as part of your genetic make-up than they do. Second, the article goes on to say that “If researchers can discover why removing the ghrelin receptor turns up brown fat’s furnace, they may be able to design a drug to do the same thing.” Hence, there may be advances on the horizon to help you speed up your metabolism by making adjustments in your composition of white and brown fat cells. We’re not there yet, but perhaps some day we will be.