Foods that are high in refined carbohydrates may trigger addictive behavior just like nicotine or cocaine, U.S. and German researchers say.

Dr. David Ludwig with Boston Children's Hospital admits that the suggestion of a food addiction is very controversial. After all, humans require food to live but don't require other addictive substances, such as alcohol or nicotine to survive. The announcement comes on the heels of the American Medical Association (AMA) declaring obesity is a disease.

"The concept of food addiction is very provocative and rightly so," says Dr. David Ludwig. "Unlike drugs of abuse, food is necessary for survival."

"We showed for the first time that refined carbohydrates can trigger food cravings many hours later, not through psychological mechanisms - a favorite food is just so tasty, you need to keep eating - but through biological effects," said Dr. Ludwig in a statement.

For the study, Dr. Ludwig examined 12 obese men and asked them to do a MRI scan after drinking milkshakes. Some of the men, however, received a milkshake which was made with a processed carbohydrate with a higher glycemic index. These "bad" carbs are found in white breads, white rices and other processed foods. They're also more quickly transformed into sugar in the blood stream.

Blood tests were also done after the men drank the milkshakes and Dr. Ludwig learnt that those who had consumed the high glycemic carbs experienced a surge in blood sugar levels; a reaction they expected. Not long after, however, their levels crashed and left them feeling hungry again. The brain scans revealed something quite interesting as well.

"Our research suggests that some of these foods might hijack the reward systems of the brain and produce symptoms related to addiction," said Dr. Ludwig.

"These results suggest that highly processed carbohydrates trigger food cravings for many hours after consumption independent of calories or tastiness, and that limiting these foods could help people avoid over-eating," said Dr. Ludwig, as cited by Time's Alexandra Sifferlin.