The junior research group “neuroendocrine mechanisms of obesity”, investigates the question how excessive food intake and weight gain modifies brain areas and functions that regulate eating behavior in the short and long-run.
Long term disturbances can be observed particularly in the hypothalamus, a crucial control center for food intake, and in the reward system, which is the positive feeling after pleasant stimuli such as eating. If the reward system of the brain responds only after massive food intake, the attempt to lose weight, and the maintenance of a weight loss becomes very difficult. A regain of the lost kilos, the so-called yo-yo effect can often be observed in these patients.
Here the hormones leptin in the hypothalamus and dopamine play important roles, dopamine is also known as happiness hormone. It is also a transmitter in the reward system that affects also activity-levels, motivation, and the feeling of pleasure, e. g. due to eating.
Diverse studies suggest that obese people need to consume more food to reach the same satisfying level of dopamine than normal weight persons. Leipzig researchers cooperate with U.S. scientists headed by Professor Ivan de Araujo from Yale University. Together they aim to decipher the neuronal and behavioral mechanisms behind this phenomenon.
Among others the fat intake seems to be responsible for the different dopamine levels in over- and normal weight people. Dopamine could be an important factor why many people gain weight after weight loss treatments, while patients who lost kilos due to obesity surgery can keep this weight reduction usually over many years.
New studies shall clarify what causes this difference, and what influence bariatric surgery has on the brain areas that control eating behavior. This could provide new approaches for non-surgical, long-term effective obesity therapies.
Dr. Wieke K. fenske heads this junior research group.