Many people find it hard to resist the craving for that last doughnut or brownie sitting on the counter, but a new BYU study shows that exercising may help resist that pervasive desire for food.
Bliss Hanlon, a former graduate student from Bethesda, Md., conducted the study along with two BYU professors — James LeCheminant, an associate professor from the Department of Exercise Sciences, and Michael Larson, an assistant professor of psychology and neurology. The study shows that a 45-minute exercise segment actually lowers a person's motivation for food.
The study included 35 women, 17 obese and 18 lean, whose brain activity was measured after one morning that included a 45-minute exercise session, and one that did not. These different conditions occurred about one week apart. Larson used EEG machines to measure the participants' neurological response to pictures of food and pictures of flowers, which were used as the control, after both situations to get an objective measurement.
A BYU student undergoes EEG testing while shown pictures of foodLeCheminant said he and Hanlon did the study to learn more about obesity and see if there was a connection with BMI, exercise and motivation for food.
'We had seen a couple of articles where they had used EEG but simply looked at people's response to pictures of food under different conditions, not exercise,' LeCheminant said. 'They were mixed. One said that those who were clinically obese actually responded more strongly to pictures of food. Then there was another paper that said there was no difference.'
Hanlon said that going into the study, they expected to see a difference in the brain responses between the obese and lean women. The study evidence indicated otherwise.
'Our findings revealed that exercise affected food motivation in all women regardless of BMI status,' Hanlon said. 'Initially, we anticipated that the effect of exercise on food motivation would differ in normal weight women compared to obese women. This finding suggests that exercise could be an effective weight management tool in all women as it is shown to temporarily suppress food motivation after a moderately intense bout of exercise.'
Reducing the short-term desire for food is just one of the findings from the study. The results indicated that on the days the participants exercised they had more spontaneous activity throughout the day.
The study results also contradict the common belief that people eat more after exercising to 'make up' the calories they burned through the activity. The researchers found that there was no difference in the participants' total energy consumption on the day they exercised and the day they did not.
Larson and LeCheminant both said the study has practical application and encourage others to see how exercising affects their motivation for food.
'Try exercising before meals and see if it affects your eating pattern,' Larson said. 'If you're more active, if you exercise, then odds are, you'll be more likely to be active throughout the day.'