What you see is what you eat: how children’s brains react to the sight of food
Why do some children become overweight while others don’t? That is one of the main questions within the I.Family project. How children’s brain reacts to food cues might give us some insight into that.
Imagine walking down the main street of any city. What do you see around you? Maybe a chain-clothing store, a department store, and: a bakery, an ice cream shop, a fast-food place, a café, a supermarket… in short: a lot of places where you can see, smell and buy food. Imagine being in a railway station, again: food is all around. What happens to you when you are constantly confronted with all these food cues? Do you give in and buy something to eat? Or can you resist temptation?
Decisions on when, what and how much to eat are taken in the brain. There all the relevant information is integrated: how hungry you are, how much you like the food you see, whether you want to lose weight etc. People differ in how their brain reacts to food cues. Research has shown that these differences can predict the chance people have of making unhealthy food choices and gaining weight.
Quite some studies have been done on how adults’ brains react to food cues, but not so many in children. In a recently published meta-analysis (http://www.ncbi.nlm.nih.gov/pubmed/25285373) we examined all studies done in children, and compared them with those done in adults. To measure brain activation, a specific type of MRI scan was used, called functional MRI (fMRI). With fMRI you can see which areas of the brain become active by seeing where the oxygen-rich blood is going, which is a indirect measure of activation. In all these studies included in the analysis, brain activation was measured with fMRI while participants viewed pictures of food. Our meta-analysis showed that children activated mostly the same areas as adults when looking at food. We mostly found areas that are part of the appetitive brain network, and areas involved in visual attention. This suggests that children might not activate areas important for cognitive control, which means that it might be harder for them to resist temptation when they see foods. We already knew that inhibition gets better with age, as the brain matures, but now there are suggestions that food-specific inhibition might be less developed in children as well.
So however hard it might be for us to resist temptation and leave all those yummy, ready-available foods: this might be even harder for children. For some of them this might even be nearly impossible. And yet a lot of food marketing is directly targeting children. Think of cereal commercials and packaging with cartoon animals, or a free toy with a hamburger meal at a fast food restaurant. If children are more vulnerable to food temptations we should be helping them to resist these, and to build their resolve to make healthy food choices. I think we should not allow children to be seduced by companies marketing unhealthy foods, and that stricter policies for food marketing targeting children should be put in place.
Floor van Meer, PhD candidate, UMC Utrecht