However, a study by the University's Institute of Psychology, Health and Society of 100 overweight and obese low fibre consumers tested whether eating prunes as part of a weight loss diet helped or hindered weight control over a 12-week period.
It also examined if low fibre consumers could tolerate eating substantial numbers of prunes in their diet, and if eating prunes had a beneficial effect on appetite.
To assess the effects of prunes on weight and appetite, participants in the study were divided into two groups - those who ate prunes every day (140g a day for women and 171g a day for men) and those who were given advice on healthy snacks over the period of active weight loss.
The researchers found that members of the group which ate prunes as part of a healthy life-style diet lost 2kg in weight and shed 2.5cm off their waists. However, the people in the group which was given advice on healthy snacks lost only 1.5kg in weight and 1.7cm from their waists.
The study also found that the prune eaters experienced greater weight loss during the last four weeks of the study. After week eight, participants showed increased feelings of fullness in the prune group. Moreover, despite the high daily doses, prunes were well tolerated.
Liverpool psychologist, Dr Jo Harrold who led the research, said: "These are the first data to demonstrate both weight loss and no negative side effects when consuming prunes as part of a weight management diet. Indeed in the long term they may be beneficial to dieters by tackling hunger and satisfying appetite; a major challenge when you are trying to maintain weight loss."
Professor Jason Halford, Professor of Experimental Psychology and Director of the University's Human Ingestive Behaviour Laboratory, added: "Maintaining a healthy diet is challenging. Along with fresh fruit and vegetables, dried fruit can provide a useful and convenient addition to the diet, especially as controlling appetite during dieting can be tough."