Experimental studies and randomised controlled trial investigating the impact of traditional dried fruits consumed as snacks on food intake, experience of appetite and bodyweight

Two studies investigating the impact of dried fruits eaten as a snack on weight control were designed to examine the effects of prunes and raisins on appetite (phase 1), and whether prunes undermine weight loss, due to the increase in energy density on drying, when included in a structured weight loss programme (phase 2). Phase 1 compared the effect on appetite of equi-weight or equi-caloric snacks of prunes (100 or 140 g) and raisins (100 or 111 g) with a control condition (100 g/335 kcal jelly babies), in a pre-load, cross-over design (n = 40 analysed). A significant effect of condition on food intake was observed, with significantly lower weight of food consumed in the 140 g prune group versus control, and on Area Under the Curve (AUC) fullness, due to a greater effect in the 140 g prune group versus control. In phase 2, change in bodyweight and waist circumference were measured in a 12-week randomised, parallel-groups intervention study (n = 100 analysed, 50 per group). Prunes (females: 140 g, males: 171 g/day) replaced usual snacks whilst following a weight loss programme. The active control group followed the same programme and participants were instructed on healthy snacking. A significant reduction in mean bodyweight in the prune group versus baseline was consistent with the phase 1 evidence that prunes can aid appetite control, although it could also be explained by overall diet in the context of a structured weight loss programme. Prunes did not produce a detrimental effect on mean weight loss over 12 weeks versus control (prune group: −1.99 kg; active control: −1.53 kg), nor on decrease in waist circumference (prune group: −2.40 cm; active control: −1.74 cm). No additional benefit on weight loss was seen (between-group difference was non-significant). The daily intake of prunes was well-tolerated. Phase 1 demonstrated that prune snacks produced beneficial changes in appetite. Phase 2 demonstrated that prunes did not undermine weight management, and this warrants further study.