This is an interesting infographic about how closely connected our brains and stomachs are. The connection is so strong that what we eat can affect our mood and thinking.
It makes sense that what you take into your body can affect how other parts of your body work. It seems like we usually think about our heart or kidneys when we think about food affecting our other organs. But the impact that food can have on the the brain is amazing.
Among other things, eating poorly can cause impaired learning, memory loss, insulin resistance, and slow cognitive function.