A low carbohydrate, Ketogenic diet might be the best way to avoid chronic disease, enhance performance, and maintain favorable body composition (an appropriate ratio of muscle to fat).
1. I was a personal trainer for about 3 years; I helped a few dozen people lose weight and get really strong. Consequently, I've experimented a lot in this area on both myself and others.
2. Insulin is a hormone in your body that transports glucose (sugar) into your cells so that they can use it for energy.
3. Excessive Insulin maintained over the course of your life is pretty bad.
4. Excess Insulin occurs, commonly, as a result of eating too many carbohydrates (fruits, potatoes, grains, vegetables, sugar). Some people's physiology handles carbohydrate intake better than others.
5. Restricting carbohydrate intake might be the single best way to improve your health, extend your life, and purge yourself of undesirable, excessive body fat.
6. The Ketogenic Diet involves eating little to no carbohydrates, thus avoiding all the issues listed above.
7. There are likely a lot of other benefits to using ketones (instead of glucose/sugar) as your primary fuel source.
Ketosis probably isn't for everyone. In fact, there's probably a certain % of the human population what would actually feel and perform worse eating this way. That said, it seems to work pretty fantastic for me. My weight is managed. I feel great. I'm more focused. I don't get super tired after lunch. Try it out, then draw your conclusions.