A personal training Cambridge fat loss report by Callie Durbrow
There have been studies conducted on the health benefits of weight loss for the long term through calorie restriction, but not many studies have looked at the stress levels and how this calorie restrictive weight loss affects hormones.
A study at the University of Pennsylvania examined hormone changes and behaviors of mice that were fed a calorie restricted diet, which produced significant weight loss over three weeks.
Previous studies have shown that withdrawal from a high fat diet has been shown to increase stress levels. This study showed that the mice that were dieting had higher levels of the stress hormone corticosterone. They also showed symptoms of depression when in stressful situations.
What I think is even more significant is that the mice had altered DNA after they were done dieting that showed changes in the genes that control appetite and stress. These changes even remained after the mice were re-fed and reached their pre-diet weights.
What this research shows is that repeated crash dieting may not only increase stress levels, but also make successful weight loss more difficult. It may make the brain more susceptible to increase future binge eating of high fat foods.
It may actually reprogram how the brain responds to these situations.
Since humans do not usually live in a restricted environment these types of stress level indicators could be important in determining the chances of long term weight loss success.
Now that they have seen these types of results in mice it will be interesting to see if humans increase the same corticosterone hormone and if human genes that control appetite and stress are modified.