Americans have gone from attachment to fast food culture to depending on it. The result: obesity; a negative effect of fast food culture. Morgan Spurlock experimented with eating McDonald's food for breakfast, lunch, and dinner; In just five days he added ten pounds. He thus discovered that fast food is the main cause of the obesity epidemic in America (Gilbert). “Functional neuroimaging studies have also revealed that the smell, taste and appearance of food produce an effect similar to that of drugs of abuse. Many of the brain changes reported for hedonic eating and obesity are also found in various forms of addiction” (Liu et al). Fast food restaurants selectively choose certain flavors and effects, to create cravings and addiction to their food. “Animal studies have shown that predisposition to food addiction in offspring was caused by feeding rat mothers junk food, consisting of fatty, sugary, and salty snacks, during pregnancy and lactation” (Liu et al). In addition to chemical factors such as ingredients like sugar and salt, external cues also lead to food cravings despite satiety. Television advertising also elicits food cues, encouraging even normal-weight children and adults to seek food despite the lack of hunger cues (Liu et al.