A new study from the University of Minnesota found that quitting smoking leads to a poor diet, potentially leading to weight gain.

The new study found that the opioid system — the brain functions responsible for addiction and appetite regulation — may cause former smokers suffering from nicotine withdrawal to prefer fatty, sugary foods to fill the void.

“We looked at whether or not acute nicotine withdrawal increases the intake of junk food — high in salt, fat and sugar — and how the stress-relieving receptors of the opioid system are involved,” al’Absi said in a press release from the university.

“These findings extend earlier studies that indicate the impact of tobacco use on appetite and help identify the influence of an important biological link, the brain opioid system, on craving during nicotine withdrawal,” al’Absi said