The food environment has changed drastically, which has. resulted in foods with increasingly addictive-like properties. In the pre-industrial era humans survived on a diet that was. minimally processed, high in protein, grains, and produce,. and relatively low in salt [20]. Foods that had greater caloric value through elevated sugar and fat content, such as berries. and animal protein, were relatively scarce. As an adaptation to motivate consumption of calorically dense foods, we. evolved to find foods high in sugar and fat more hedonically. rewarding than foods low in these substrates [20]. As industrialization occurred and food-related technology.