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 evolved, the environment changed from one with limited. access to calorie-dense foods to one of abundance with. artificially elevated levels of fat, sugar, salt, caffeine and. flavor enhancers in the meals we eat.
Many highly processed foods have been altered in a. similar manner as addictive drugs. Both the elevated potency of a substance, and its rapid absorption into the bloodstream,. increase a substance's addictive potential [22]. Many drugs of abuse derive from plant materials that are refined into. highly concentrated substances (eg, grapes into wine; the. coca leaf into cocaine). As a result of processing, these. substances became more potent and the active ingredients is. more quickly absorbed into the bloodstream. For example, when the coca leaf is chewed or stewed as tea, it produces. only mild stimulation and is thought to have little addictive. potential [23]. Further refinement provides a more potent drug in the form of cocaine and crack, which is hedonically. very rewarding, quickly absorbed, and highly addictive [24]. Many highly palatable foods follow a similar process that. results in the quicker absorption of sugar and a higher level. of reward. For example, corn is a frequently consumed. starchy vegetable that has been part of the human diet for. centuries. With technological advances, corn was refined. into high fructose corn syrup (HFCS) - a highly. concentrated and very sweet simple carbohydrate, which is. not found in natural foods that comprise most traditional. diets [25]