One way of dieting is eating low calorie healthy food and then allow a “free day”. The idea is that if you can look forward to having your favorite high fat, high sugar foods, you will stick to your diet. This is the basis of some popular diet plans including Body For Life.
New evidence suggests that this might not be a good strategy, and that this may actually make dieting harder.
The new study divided rats into two populations. One group got regular chow every day; the second group got regular chow for 5 days and sweet chow for 2 days.
After a few weeks the group that got the cycling food, had changed their eating habits. When this group got regular food they were less interested in food and avoided anxiety-provoking situations. When they got the sweet chow, their behavior returned to a normal less anxious behavior (the same as the group getting only regular chow), but they ate more.
The researchers then analyzed stress proteins and found a stress neuropeptide (CRF) was increased on the days the rats got normal chow. Increase of CRF and anxiety is associated with drug withdrawal.
This suggests that after a few cycles of having free days, that there are withdrawal symptoms and intense cravings for sweet foods. The body goes into withdrawal and craves “bad” foods, the same way that a drug addict goes into withdrawal, get anxious and craves the drug.
Additionally comfort eating may become more common. Increased anxiety and feelings of stress when the withdrawal symptoms hit, is likely to lead to eating of bad foods for comfort.
The research suggests that free days may actually undermine dieting and increase the likelihood of bingeing on high calorie tasty foods.
