A drug prescribed for weight loss and type 2 diabetes may improve associative learning in people with obesity, a recent study has found.

Associative learning is the process by which living things learn about the connections between things happening around them. It involves both modifications of existing behaviors and the development of new behaviors.

Researchers from Max Planck Institute for Metabolism Research evaluated how associative learning changes in people with impaired insulin sensitivity associated with obesity. They studied associated learning behaviors in two groups of participants; one with normal weight, who had high insulin sensitivity, and the other with reduced insulin sensitivity from obesity. The team found that reduced insulin sensitivity from obesity impairs associative learning.

The participants in the obese group were either given a placebo or liraglutide – a weight loss drug prescribed for obesity and type 2 diabetes.

With a single dose of liraglutide, the impaired associative learning in obese people can be reversed and brought back to the levels same as that of people with normal weight, according to the findings, published in the journal Nature Metabolism.

"These findings are of fundamental importance. We show here that basic behaviors such as associative learning depend not only on external environmental conditions but also on the body's metabolic state. So, whether someone has overweight or not also determines how the brain learns to associate sensory signals and what motivation is generated. The normalization we achieved with the drug in subjects with obesity, therefore, fits with studies showing that these drugs restore a normal feeling of satiety, causing people to eat less and therefore lose weight," study leader Marc Tittgemeyer said in a news release.

The study shows how obesity can alter the brain and how the process can be modified with medication. The researchers plan to carry out further studies to understand how liraglutide works at a molecular level. They also plan to explore if other approaches such as weight loss trials and insulin sensitizers can also bring in similar improvements.

"While it is encouraging that available drugs have a positive effect on brain activity in obesity, it is alarming that changes in brain performance occur even in young people with obesity without other medical conditions. Obesity prevention should play a much greater role in our healthcare system in the future. Lifelong medication is the less preferred option in comparison to primary prevention of obesity and associated complications," said Ruth Hanßen, first author of the study and a physician at the University Hospital of Cologne.