
Keeping your blood sugar balanced is probably the most important factor in maintaining even energy levels and weight. The level of glucose in your blood determines your appetite. When the levels drop, you feel hungry. The glucose in your bloodstream is available to your cells to make energy. When levels are too high, the body converts excess glycogen (a short term fuel store mainly in liver and muscle cells) or fat, to our long term energy reserve. When blood glucose levels are too low, we experience symptoms including fatigue, poor concentration, irritability, nervousness, depression, sweating, headaches, and digestive problems. An estimated three in every ten people have impaired ability to keep their blood sugar levels even. They may go too high, and then drop too low. The result, over the years, is that people become increasingly overweight and lethargic. But if you can control your blood sugar levels, the result is even weight and constant energy.
Source:
Holford, Patrick. The New Optimum Nutrition Bible. 2005. Crossing Press, Berkeley, CA