Whether you choose celery or chocolate could be a question of how quickly your brain takes healthfulness into account, according to a new study by a team of neuroeconomists at the California Institute of Technology.

"What we wanted to find out was at what point the taste of the foods starts to become integrated into the choice process, and at what point health is integrated," says lead author Nicolette Sullivan, a graduate student at Caltech.

Spring boarding on the understanding that people know which foods taste good to them and which ones don't, the researchers hypothesized that taste is the first attribute that people judge in a food when deciding whether or not to eat it, while healthfulness is a secondary consideration, and possibly a tertiary one for individuals with less than normal self-control.

The research team tested their hypothesis on 28 undergraduate subjects who hadn't eaten for four hours prior to experimentation.

Participants were asked to rate 160 foods individually on a scale from -2 to 2 in terms of healthfulness, taste and how much they thought they would enjoy it after the experiment.

Next, they viewed the same foods in 280 random pairings and were asked to choose a favorite in each of the pairs and declare it with a click of the mouse.

Their cursor movements were made available to the researchers as a tool to help trace and analyze the decision process, so researchers could tell if, for example, a participant had been tempted to choose the pizza instead of the peas but then switched back to the peas, likely in the interest of health.

Cursor-track analysis indicated that taste came into play around 200 milliseconds earlier than health in the participants' food choices and 32 per cent never considered health at all.

Participants were then split into two groups according to the amount of self-control their food choices indicated.

Those with the least amount of self-control began to consider the health aspect of a food 323 milliseconds later than those with the most, indicating that the quicker someone begins to consider health, the more self-control he is likely to exert.

Sullivan says her findings mean it could be a good idea to wait a bit longer before deciding what to eat.

The study was published in the journal Psychological Science.