OK, in another thread there is a reference to “setpoint,” which has been around for some years. Basically, that your body is programmed to maintain a certain weight more or less.
As I understand it, a theory is a model constructed to explain the relationship between known facts.
So. . .
What are the “facts” behind “setpoint theory?”
I’m just a little skeptical on this subject since the first reference I saw to it some years ago was on a late-night infomercial. (“Buy our product to learn how to raise your setpoint.”)
Someone posted this excellent article in the fat/thin thread below.
Basically, the hypothesis (I think it’s more of a hypothesis anyways), is that each person has a physiological preference for a particular weight. Get below it, and the person receives cues to eat more, and their metabolism becomes more efficient (burning fewer calories to accomplish the same work). Get above it, and the person receives cues to eat less, and their metabolism picks up a bit.
The hormone leptin is involved. When a person’s weight is greater than their setpoint, fat cells turn out leptin to inform the brain that there’s plenty of storage already. If they fall below their setpoint, the leptin slacks off, so the brain knows to start aquiring more calories.
However, severely obese people have tons of leptin, which leads some researchers to believe that leptin tolerance may complicate obesity and weight loss.
Setpoints can be changed, but it’s much easier to raise the setpoint than lower it. The article mentioned that when lowering the setpoint, it takes about three years’ time to revise the setpoint lower - and all that time, your body is yelling at you to gain weight.
Mjollnir-I mentioned a setpoint in my post to the fat or thin debate.
For more information about leptin, go to: http://www.ncbi.nlm.nih.gov/PubMed and type in leptin in the search field. (PubMed is also a great resource for any question about biological research). I got over 2500 hits.
Of course, scientific abstracts make for pretty dry reading unless you have an interest. Try some other key words. It’s late so I didn’t read the entire New Yorker article that phouka linked to, but it’s more comprehensible to the average Joe than scientific journal articles–just be wary that the writer might not be an expert in the field, but instead a free lance writer who does his/her best to distill the facts as he/she understands them.
I’ve got a pretty good journal article about leptin and 'set points" in my files at my office; I’ll try to find it and post it when I’ve got time.
As far as infomercials go, I might believe a used car salesman has more honesty with regard to his product.
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Every time I hear the phrase “just a theory”, I want to slap somebody up side the head. The phrase is usually said by someone who does not know the difference between theory and WAG and “reasons” that “scientific” creationism should be taught along with evolution in schools because evolution is “just at theory”.
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