Low blood sugar can occur one to three hours after eating, leaving you feeling fatigued and hungry again. Called reactive hypoglycemia, this type of low blood sugar isn't associated with diabetes and doesn't indicate an underlying medical condition. Reactive hypoglycemia usually doesn't require medical treatment -- just some simple dietary changes.
Reactive Hypoglycemia
When you eat, your body converts food into glucose, your primary source of energy. Certain types of food, especially sugar and other simple carbohydrates, are quickly turned into energy. The faster glucose hits your bloodstream, the more likely your body is to over-react, often by releasing too much insulin. This leads to low blood sugar, or reactive hypoglycemia, after eating. It can happen as soon as one hour after you start eating, or you could start to feel the symptoms, such as fatigue, hunger, headache and mood swings, up to three hours after eating.
Preventing Reactive Hypoglycemia
If you can control the speed your body converts food into glucose, you can prevent reactive hypoglycemia. Choose foods that slow digestion -- high-fiber complex carbohydrates, fat and protein. Avoid added sugars, starchy vegetables and products made from refined white flours. Eating whole grain bread instead of white bread and brown rice instead of potatoes will give your body a steady supply of glucose -- not a rush of too much at once. Smaller meals and eating more frequently will also help to regulate glucose and insulin production.
Menu Ideas
The trick to controlling reactive hypoglycemia is to eat often -- every two three hours. You don't want to eat too much at one sitting; which could lead to consuming too many total calories and weight gain, or could speed up digestion and still cause low blood sugar. Always combine high-fiber carbs with unsaturated fat and lean protein. Try a turkey sandwich on whole-grain bread with slices of avocado, vegetables and hummus, fruit with low-fat yogurt or nut butter. Try not to eat carbs by themselves -- if you're going to eat a piece of fruit, have a handful of nuts, as well.
Other Causes of Hypoglycemia
Reactive hypoglycemia can be hard to diagnose; it can be caused by hormone imbalances, such as a sensitivity to glucagon or adrenaline or even an over-production of insulin. Because symptoms disappear after you eat again, it becomes hard for a doctor to tell whether there is a problem. Dietary changes should prevent low blood sugar. However, if you still feel tired after eating, there may be a different cause for your low blood sugar. Tumors in your pancreas, liver disease and alcoholism can cause low blood sugar. You'll need to address underlying medical problems before you can prevent hypoglycemia.
