Cut grains.
Credit: Getty Images

Since the advent of agriculture, we've slowly increased our grain consumption. Today, some of the cheapest and most readily available foods are made from inexpensive, subsidized grains such as corn and wheat. These foods, like cereal, bread, pasta, and pizza, are also largely devoid of nutrients. They drive up insulin, putting our bodies in fat-storing mode, and cause us to crave more of them by the use of chemical additives.