People with obesity have a significantly lower number of neurotransmitters dedicated to generating pleasurable sensations than people of a normal weight, according to a study, which could explain why they have difficulty restraining their eating.

Researchers from Aalto University and Turku University, both in Finland, have found obesity is associated with molecular changes to the brain – including fewer opioid receptors, which allow people to experience pleasurable sensations.

The researchers suggest that the lack of opioid receptors predisposes obese individuals to overeating, as they compensate for decreased pleasure responses.

While the academics do not know yet whether the altered brain neurochemistry is a cause or consequence of obesity, these findings have implications for the understanding of obesity and why people often have problems restraining their eating habits.

“[The results] help us to understand the mechanisms involved in overeating and provide new insight into behavioural and pharmacological treatment, plus the prevention of obesity,” said one of the study’s professors, Lauri Nummenmaa.

No changes were observed in the dopamine neurotransmitter system, which regulates motivational aspects of eating.

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