The study debunks the myth that cigarettes keep weight down, says an Australian research team from the University of New South Wales and the University of Melbourne.
Researchers conducted the study on mice over seven weeks. Half the mice were exposed to smoke from four cigarettes a day for six days a week, while the other half were smoke free.
The study found smokers lost muscle mass, which gave them the appearance of being thinner, but the fat instead was stored around their vital organs.
While mice on the smoke diet ate about 23 percent less calories, they retained their fat mass to pre-smoking levels.