Why do i get sleepy after eating starchy foods? usually when i eat bread, pasta or potatoes. it doesn't seem to matter how much/little i eat of it.

Sugar: Simple carbohydrates are starchy foods that contain only one or two types of sugar. Unlike complex carbohydrates such as legumes and whole grains, many simple carbohydrates tend to cause dramatic spikes in blood sugar that can result in feelings of sleepiness and drowsiness. For best result, adopt a diet that emphasizes foods with low glycemic index.