While the immune system is very complex, one thing is sure—what you eat can influence how well you can fight disease. Energy intake has an important influence, so if you are restricting calories, or over-eating, your immune system may suffer. Make sure you are getting enough of the right kinds of foods by using FoodTrack—Check on Balance. For an extra immune boost, try including probiotic foods like yogurt. Research shows that probiotic bacteria, included in many yogurts, stimulate immune activity.