I came across a great paper the other day which discussed the role of the nervous system in weight loss and gain. Scientists have known for decades that the body has built-in mechanisms to regulate body weight. If a person cuts calories too much, the metabolism will slow in response to this. Conversely, if a person consumes too many calories the body will increase its metabolism (primarily through thermogenesis - heat production).
The problems begin when a person stays overweight long-term. In the ancestral environment, people weren't overweight in the long-term because there weren't sustained periods of excessive calorie consumption and/or decreased activity. In the modern world, this situation is the norm.
When someone becomes overweight nowadays, the sympathetic nervous system is activated as the body increases its heat production. However if the person is sedentary and stays overweight, this "switch" never gets turned off. In essence, this switch stays on for years and years, and not surprisingly has deleterious effects. Over time, the body's tissues respond less and less to this increased nervous system activity, and the strength of this corrective response is weakened.
The author's summarize this process nicely in the abstract: "As a result, age-associated SNS activation, initiated as a consequence of accumulating adiposity with the intent of preventing further fat storage, ironically, may in time evolve into a potential mechanism contributing to the development of obesity with aging."
I came across a great paper the other day which discussed the role of the nervous system in weight loss and gain. Scientists have known for decades that the body has built-in mechanisms to regulate body weight. If a person cuts calories too much, the metabolism will slow in response to this. Conversely, if a person consumes too many calories the body will increase its metabolism (primarily through thermogenesis - heat production).
The problems begin when a person stays overweight long-term. In the ancestral environment, people weren't overweight in the long-term because there weren't sustained periods of excessive calorie consumption and/or decreased activity. In the modern world, this situation is the norm.
When someone becomes overweight nowadays, the sympathetic nervous system is activated as the body increases its heat production. However if the person is sedentary and stays overweight, this "switch" never gets turned off. In essence, this switch stays on for years and years, and not surprisingly has deleterious effects. Over time, the body's tissues respond less and less to this increased nervous system activity, and the strength of this corrective response is weakened.
The author's summarize this process nicely in the abstract: "As a result, age-associated SNS activation, initiated as a consequence of accumulating adiposity with the intent of preventing further fat storage, ironically, may in time evolve into a potential mechanism contributing to the development of obesity with aging."