DECLINING house prices, rising job layoffs, skyrocketing oil costs and a major credit crunch have brought consumer confidence to its lowest point in five years. With a relatively long recession looking increasingly likely, many American families may be planning to tighten their belts.

Interestingly, restraining our consumer spending, in the short term, may cause us to actually loosen the belts around our waists. What’s the connection? The brain has a limited capacity for self-regulation, so exerting willpower in one area often leads to backsliding in others. The good news, however, is that practice increases willpower capacity, so that in the long run, buying less now may improve our ability to achieve future goals  like losing those 10 pounds we gained when we weren’t out shopping.

The brain’s store of willpower is depleted when people control their thoughts, feelings or impulses, or when they modify their behavior in pursuit of goals. Psychologist Roy Baumeister and others have found that people who successfully accomplish one task requiring self-control are less persistent on a second, seemingly unrelated task.

In one pioneering study, some people were asked to eat radishes while others received freshly baked chocolate chip cookies before trying to solve an impossible puzzle. The radish-eaters abandoned the puzzle in eight minutes on average, working less than half as long as people who got cookies or those who were excused from eating radishes. Similarly, people who were asked to circle every “e” on a page of text then showed less persistence in watching a video of an unchanging table and wall.