Washington DC: Suggesting overweight people to eat healthily may be a futile step as a recent study has found that their brains override rational advice when presented with real food.
The University of Cambridge researchers found that when making hypothetical food choices, lean and overweight people showed highly comparable patterns both in terms of their choices and the accompanying brain activity.
The activity in the brain was a good predictor of which foods they would choose when later faced with a selection of real food choices. But the presence of real food influenced choices differently across the groups.
In a related study, the researchers show that the brain structure in obese people differs from that in lean individuals in key regions of the brain involved in processing value judgements.
"There's a clear difference between hypothetical food choices that overweight people make and the food they actually eat," said researcher Nenad Medic, adding "Even though they know that some foods are less healthy than others and say they wouldn't necessarily choose them, when they are faced with the foods, it's a different matter."
Medic noted that this is an important insight for public health campaigns as it suggests that just trying to educate people about the healthiness of food choices is not enough. The presence of unhealthy food options is likely to override people's decisions. In this respect, food choice does not appear to be a rational decision - it can become divorced from what the person knows and values.
Co-author Theresa Marteau added that these findings attest to the power of environments in overwhelming many people's desires and intentions to eat more healthily. The findings also reinforce the growing evidence that effective obesity policies are those that target food environments rather than education alone.
The study is published in the journal eNeuro.