Did you put on weight after menopause without any change in your lifestyle?
Did people tell you that you were probably eating more and exercising less without realizing it?
Did you think maybe you were going nuts?
Well, now a study has shown that this weight gain may not be your fault.
"When women approach menopause, they gain weight in fat and their energy expenditure goes down," says Deborah Clegg, the senior author of the study, which showed that estrogen receptors in the brain may be responsible for the change in metabolism.
When the researchers deleted particular estrogen receptors called estrogen receptor-a from the entire brains of mice, the mice became "very, very fat." They ate more and burned less.
But when they deleted the same receptors from just one type of brain cells, called SF1 neurons, the mice gained weight without eating any more.
Deleting the receptors from another type of brain cells, the POMC neurons, resulted in the opposite. The mice ate more but didn't gain weight.
In other words, depending on where the estrogen works in the brain, you may eat more or gain weight without changing your diet at all. The researchers suggest that targeting estrogen replacement to specific areas in the brain might significantly affect metabolism and the risk of becoming diabetic.
Similar results were not seen in male mice, but the researchers said they suspect that other unknown receptors play similar roles in males.
Note that these studies were done in mice, and mouse studies don't always translate into human therapy. Nevertheless, they do illustrate what most of us with weight problems probably already know but thin people don't usually believe: Weight gain may not be your fault.
We don't yet know exactly how to manipulate the various nervous system and hormonal signals that control appetite and metabolism. But some day we will. I'm looking forward to that day.
Published On: October 25, 2011