Caloric Restriction + Exercise = Longer Life
As times change and generations become more health conscious, weight often becomes an issue. Due to the fact that 33.9% of adults aged 20 years and over are deemed obese, fat loss is a hot topic in the United States.1 People are becoming more and more educated and learning that dietary changes such as calorie restriction are beneficial in helping with fat loss.
Recently, research correlated calorie restriction with a longer life, as well. The research proved that dietary restriction in the form of calorie restriction can slow age-related diseases and extend the lifespan of many forms of life, including humans. Additionally, investigators have discovered that dietary restriction causes enhanced fat metabolism in the muscles and increased physical activity.2
This recent study was done on fruit flies and is published in the latest issue of the Cell Press Journal Cell Metabolism. To help pinpoint specific effects of the dietary restrictions on the body, the researchers removed yeast from the flies’ diets and then had various tests performed. The results of this procedure showed that restricting the yeast, the major source of protein in their diet, significantly prolonged their lives. Following the dietary restriction, the flies became more physically active. Consequently, this increased physical activity was determined to be a factor for the extension of their lifespan, since flies in a separate group, which had a restricted diet and could not move, did not live longer.3
The results showed that the increased physical activity was the result of a shift in the flies’ metabolisms, so that they increased both fat synthesis and breakdown. Just blocking fat synthesis alone in the muscle tissue cancelled out the life-extending effects of calorie restriction.4
The researchers also found that overexpression of the hormone AKH, the fly equivalent of glucagon, enhanced flies' fat metabolism, boosted their activity, and extended their lifespan even though their diet was not limited. Glucagon is a hormone that is produced in the pancreas and is used to raise very low blood sugar.5
Senior author Dr. Pankaj Kapahi, from the Buck Institute for Research on Aging stated:
Ours is the first study to suggest that for dietary restriction to enhance lifespan, you need increased fat turnover in the muscle and an associated increase in physical activity. Furthermore, it also suggests that dietary changes may enhance motivation to exercise and help derive maximal benefits of exercise.6
"Our data suggest that dietary restriction may induce changes in muscle similar to those observed under endurance exercise and that molecules like AKH that enhance fat breakdown could serve as potential dietary restriction mimetics," the authors wrote. This indicates that medical interventions that enhance fat metabolism in muscle might have the potential to prolong life.7
In a nutshell, the results of the study indicate that if you are looking to add some years to your life, cutting calories does play a major role, but to truly reap the life-extending benefits, it should be coupled with physical activity such as exercise.8
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