Why is it so hard to give up cheeseburgers and french fries? According to researchers at the Scripps Research Institute in Florida, it could be because junk food addiction is actually similar to addiction to drugs like heroin and cocaine.
The researchers found that lab rats, when given the chance to eat an unlimited supply of salty, sugary and fatty foods, gained more weight than those who did not have an unlimited supply of junk food. When the researchers took away those rats' access to junk food—instead, giving them more nutritious foods—the rats simply refused to eat for up to two weeks. And after they became obese, the rats had diminished pleasure sensors in their brains, causing them to eat even more junk food.
This change in brain chemistry and behavior from overeating of junk food mimics that of drugs.