Researchers at Yale School of Medicine in the US zeroed in on a set of neurons in the part of the brain that controls hunger, and found that these neurons are not only associated with overeating, but also linked to non-food associated behaviours, like novelty-seeking and drug addiction.
While both are linked to the brain's "reward" circuitry, a desire to eat was linked to decreased interest in 'novelty' behaviour such as drugs, the researchers found.
"Using genetic approaches, we found that increased appetite for food can actually be associated with decreased interest in novelty as well as in cocaine, and on the other hand, less interest in food can predict increased interest in cocaine," Dr Marcelo Dietrich, who led the research, was quoted as saying by the Daily Mail.
For their research, the team studied mice in which a signalling molecule that controls hunger-promoting neurons in the hypothalamus was taken out.
The mice were given various non-invasive tests that measured how they respond to novelty, and anxiety, and how they react to cocaine.
Study co-author Prof Tamas Horvath said: "We found that animals that have less interest in food are more interested in novelty-seeking behaviours and drugs like cocaine.
"This suggests that there may be individuals with increased drive of the reward circuitry, but who are still lean.
"This is a complex trait that arises from the activity of the basic feeding circuits during development, which then impacts the adult response to drugs and novelty in the environment.
"There is this contemporary view that obesity is associated with the increased drive of the reward circuitry.
"But here, we provide a contrasting view: that the reward aspect can be very high, but subjects can still be very lean.
"At the same time, it indicates that a set of people who have no interest in food, might be more prone to drug addiction."
The study was published in journal Nature Neuroscience.