SnackWell Effect

The SnackWell effect, named for the SnackWell's brand of reduced-fat cookies, describes the tendency of dieters to eat more of a food, or a larger portion of it, once they believe it is a low-calorie or low-fat version, often ending up consuming as much or more than they would have eaten of the ordinary full-fat product. The pattern emerged as a term during low-fat dieting trends of the 1980s and 1990s and is also referred to as a form of moral licensing, in which permission to indulge, granted by a food's healthier reputation, leads a person to overconsume it. Researchers have identified comparable rebound patterns outside of diet, including a 2008 study finding that households with energy-efficient washing machines ran more loads of laundry, and that energy-efficient lighting was left on longer, together erasing between five and twelve percent of the energy savings the efficient appliances were expected to provide.