Wildly fluctuating blood sugar levels can be a symptom of serious illness. If you feel inexplicably sleepy, thirsty, shaky or famished even though you have eaten recently these could be signs of problems with your blood sugar levels. Your doctor will want to check that you are not suffering from diabetes or another serious condition. Assuming that you are reasonably healthy the most likely cause of unstable blood sugar levels is your diet. What you eat affects how much sugar enters your bloodstream. Sugar is a carbohydrate and more complex carbohydrates such as fruit, vegetables and grains are broken down into sugars in the digestive process. Some foods such as sugar itself, sweetened refined products such as biscuits and cakes and white bread will cause a quick release of sugars into your bloodstream. If these are not combined with slower release carbohydrates in the diet you may suffer symptoms similar to those suffered by people in the early stages of diabetes. Slower release carbs include porridge made with water, lentils, wholemeal breads and pasta, beans (but not those processed and canned with sugar) and tart fruits such as cherries and grapefruit. An index of foods rated according to the speed at which they release sugar into the bloodstream is available on the Internet. Search for "the glycaemic index".
