I would bet you feel better for all the sugar. In addition to added sugar, corn syrup, cane or beet juice, etc... alll the highly processed foods consists of wheat, corn, rice, and or soy as the base. AIl the highly processed ingredients quickly break down in the body to sugar. When you eat whole natural foods (meats vegetables) the carbohydrates break down much slower. Less insulin relase into the blood. The body has to adjust. Takes a few months. On the other side of the carbohydrate "addiction" you will feel better and your performance will increase
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As for diet, I prefer the Paleo or Weston A. Price approach. The later allowing for some grains, legumes, and dairy