Your inner four-year-old may be behind those candy cravings

If you just can't say no to sweets, turns out you might be programmed that way.

Researchers recently checked back with participants from a classic study that asked four-year-olds to choose: Eat one marshmallow now, or wait 15 minutes and get two. This year's follow-up study did brain scans on the now fortysomething participants and found those who had strong willpower showed more activity in a behaviour-control region, while those who didn't had more activity in a pleasure and reward area.

Regardless of the camp you fall into, cultivate control by substituting good habits for bad (like chewing gum instead of smoking or snacking) and practising mindful eating by asking yourself if you're truly hungry or just bored, says Douglas Saunders, a psychologist and assistant professor at the University of Toronto.