Effects of snack consumption for 8 weeks on energy intake and body weight

Background: Consumption of snacks might contribute to the obesity epidemic. It is not clear how the moment of consumption and energy density of snacks can influence the compensatory response to consumption of snacks in the long term. Objective: To investigate the effects of snack consumption for 8 weeks on changes in body weight, emphasizing on moment of consumption and energy density. Design: In total, 16 men and 66 women ( mean age 21.9 years (s.d. 0.3 year), mean body mass index 20.7 kg m(-2) (s.d. 0.2 kg m(-2))) were randomly assigned to one of four parallel groups in a 2 x 2 design: snacks consumed with or between meals and snacks having a low (<4 kJ g(-1)) or high (>12 kJ g(-1)) energy density. For 8 weeks, subjects consumed mandatory snacks that provided 25% of energy requirements on each day. Body weight, body composition, physical activity level ( PAL) and energy intake were measured in week 1 and week 8. Results: There were no differences in changes in body weight between the four groups. Moment of consumption (P = 0.7), energy density (P = 0.8) and interaction (P = 0.09) did not influence body weight. Similarly, there were no differences in changes in body composition, PAL and energy intake between the four groups. Conclusions: Body weight after 8 weeks of snack consumption was not affected by moment of consumption and energy density of snacks. This finding suggests that consuming snacks that are high or low in energy density does not necessarily contribute to weight gain. Healthy, nonobese young adults may be able to maintain a normal body weight through an accurate compensation for the consumption of snacks. International Journal of Obesity ( 2010) 34, 319-326; doi: 10.1038/ijo.2009.243; published online 24 November 2009