Are you having concentration problems in the afternoon? Do you go through a variety of emotions such as tiredness and laziness during this time? This is likely due to the types of foods that you had for lunch. A lunch that carries a large number of carbohydrates such as wheat products including bread, rice and pasta along with high-sugar drinks such as pop can significantly increase your blood sugar levels. This will cause your energy levels to rise to extreme levels temporarily. You will feel an influx of energy until your body begins to release insulin from its pancreas. Upon the release of insulin, it directs the extra glucose from carbohydrates into your bloodstream. However, your pancreas has a strong tendency of overcalculating the amount of insulin that needs to be released, causing too much glucose to be released. This can cause your blood sugar to experience a steep drop, causing lower blood sugar levels as well as more fatigue on yourself.