There's more to dieting than just sheer willpower and self-control. The presence of friends, late night cravings or the temptation of alcohol can often simply be too strong to resist. Research led by Heather McKee of the University of Birmingham in the UK monitored the social and environmental factors that make people, who are following weight management programs, cheat. The study is published in the Springer journal Annals of Behavioral Medicine.

Eighty people who were either part of a weight-loss group or were dieting on their own participated in the one-week study. They were given mobile phones on which they kept an electronic diary of all the temptations that came their way, and the situations during which they gave in to these temptations. This helped the researchers to make a complete real-time record, known as 'ecological momentary assessment,' of participants' dietary temptations and lapses.

Participants lapsed just over 50 percent of the time when tempted, and were especially vulnerable at night. They were more likely to give in to alcoholic temptations than to eat a sugary snack or to overindulge. Their willpower was also influenced by the presence of others, regardless of whether a dietary temptation was unexpected or whether the dieter went looking for something to eat. The stronger the dietary temptation, the more likely a participant was to lapse. Not surprisingly, most participants reported that they were more aware of their eating behavior while keeping their diet diaries.

The findings could be valuable for dietary relapse and weight maintenance programs. They highlight the possible future use of mobile phone applications to support people who are dieting. Following a lapse in such programs, the findings also stress the importance of including specific coping mechanisms and reinforcing a person's self-efficacy, in other words, bolstering their belief in their own ability to reach their goals.

"The findings help piece together the complex jigsaw surrounding the daily predictors of dietary temptations and help us to better understand how dietary temptations and lapses operate," says McKee. "In the fight against obesity, we need to help people become more aware of the various personal, situational, and environmental factors that expose them to dietary temptations. In doing this, we can help them to develop the necessary skills to cope successfully with dietary temptations and prevent lapses."