When a person loads up their plate with many good foods, only to waste half of it because they’re full, we say “his eyes are bigger than his stomach.” Unfortunately, though, some folks like certain foods so much that they’ll clean their plate, then go for second helpings, even if they really don’t need the extra calories. While many people who overeat feel bad about doing so afterwards, they may lack sufficient willpower to control their portions and food choices during mealtime.
Why is this? Some researchers believe that dopamine, a hormone that’s associated with both addiction and pleasure, plays a role in why we overeat certain foods. According to a recent article at NationalGeographic.com, it’s been difficult to prove the connection between dopamine and overeating because the commonly used measurement tools (such as spinal taps) are either risky to use, expensive, or both.
However, researchers recently decided to try using electroretinography (ERG), an ophthalmological procedure for examining the retina, to detect dopamine levels in test subjects. The researchers chose ERG because there are dopamine receptors in the retina: Once activated, the researchers would be able to see the activation using the ERG.
Test subjects were given either water, chocolate brownies, or Ritalin, a stimulant drug that increases dopamine levels. Test subjects who drank water showed no change in dopamine levels, while brownie-eaters and Ritalin-takers showed similar activity in their retinas.
National Geographic reports that this data is exciting for obesity researchers, as it might be an effective tool for determining “trigger foods” for obesity patients. If a person who struggles with their weight regularly, but unconsciously, chooses foods that trigger strong dopamine surges, they are perhaps doing so because the dopamine makes them feel rewarded . . . even if the foods consumed aren’t healthy. By helping these people understand their trigger foods, health care workers can assist the overweight and obese in learning to avoid foods that they’ll overeat.