Researchers came up against a puzzling finding in recent studies of eating habits: It seems everyone prefers higher-Calorie foods, whether they are overweight or obese or not. But it appears that con-scious choices are not involved…
It seems folks prefer higher-Calorie foods – whether they are overweight or obese or not.
Scientists and physicians have long believed that folks who tend towards obesity have some kind of impairment in their brain’s ‘fullness’ signal receptors. Or their dopamine-triggered pleasure centres. But now, they say that may not be the case…
Unconscious drivers?
The team, working under Dr. Albino Oliveira-Maia from the Champalimaud Foundation (Portugal), wanted to test the currently accepted wisdom. They expected to confirm that people suffering with obesity often have impairments in areas of the brain where dopamine is released may drive reward-related eating and a preference for energy-dense foods rich in fat and sugars.
They compared food preferences in three groups: 11 individuals with obesity, 23 post-bariatric (gastric restriction) surgery patients, and 27 non-obese control subjects.
Participants were provided with sweetened low-fat yogurt with and without maltodextrin (a carbo-hydrate that adds calories to the yogurt with no impact on taste or texture). They ate the yogurt at home, alternating between the maltodextrin-containing and -free yogurt. Each participant ate as much of the assigned yogurts as they wished.
What they found
“We were very intrigued that […] behavior was guided towards eating yogurts with higher energy-content,” the study report records. “[But] this did not seem to be a result of explicit choices, since consistent changes in pleasantness of flavors enriched with carbohydrates were not found.”
Importantly, “[T]his behavior was maintained in patients with obesity and after weight-loss surgery, even though there were important differences in their brain dopamine system[s].”
The takeaway
Simply put, the team found that some unconscious mechanism, not connected with fullness- or pleasure-signalling systems, was responsible for the brain detecting higher-Calorie foods and triggering a preference for them.
My take
The study’s results clearly suggest that, “Eating sends signals to the brain with information about a food’s energy content, which can influence food preferences irrespective of flavor.”
If we are to successfully meet the challenge posed by the current obesity crisis, we need to identify that underlying mechanism, and learn how to control it…
As is often said in reference to studies such as this one, more search is definitely needed, And the sooner the better…
~ Maggie J.