Individuals, whether they are obese or not, showed a preference for higher-calorie foods, even when the taste and texture were similar, according to recent research.
A study published on December 17 in the open-access journal PLOS Biology by Albino Oliveira-Maia and his team from the Champalimaud Foundation in Portugal highlights that both individuals with and without obesity favored higher calorie options.
When we eat, our brains receive signals that provide information regarding a food’s caloric value, which can significantly affect our food choices, regardless of taste. Those who are obese may have dysfunction in brain regions that involve dopamine release, a neurotransmitter that plays a key role in reward-driven eating and the attraction to energy-rich foods high in fats and sugars. It’s observed that post-bariatric surgery weight loss can lead to a more normalized eating behavior associated with a preference for healthier foods, although the specific mechanisms underlying this change remain unclear.
The researchers conducted a study involving a large sample of healthy individuals, comparing food preferences across three groups: 11 people with obesity, 23 patients who had undergone bariatric surgery, and 27 non-obese controls. Participants were offered sweetened low-fat yogurt, both with and without maltodextrin (a carbohydrate that increases the calorie content without altering taste or texture). They alternated consuming the yogurt at home, including both versions. Interestingly, all three groups consumed more of the yogurt that contained maltodextrin, even though they rated both types equally enjoyable. Notably, the response to maltodextrin was comparable between those with obesity and their non-obese peers.
The study employed radioactive iodine labeling and single photon emission computed tomography to visualize dopamine receptors in participants’ brains. Findings aligned with prior research, indicating that individuals with obesity had a lower availability of dopamine receptors compared to non-obese individuals. In contrast, both the surgical patients and non-obese groups showed similar levels of dopamine receptor availability, which correlated with more controlled eating behaviors. This suggests that the brain changes associated with obesity might be reversible following bariatric surgery, which could affect overall food intake without necessarily altering the types of food people prefer.
The authors noted, “We found it quite fascinating that while participants gravitated towards higher-calorie yogurt, this preference did not appear to stem from conscious choices, as there were no significant changes in the perceived pleasantness of flavors enhanced with carbohydrates. Importantly, this trend continued among individuals with obesity and after weight loss surgery, despite notable differences in their brain’s dopaminergic systems.”
