Summary
Snacking, or the habit of eating little and often, has been postulated to have a range of health benefits in relation to appetite control, bodyweight management and improved blood glucose control in diabetics and pre‐diabetics. However, there is widespread agreement that our current obesogenic environment is encouraging overeating in response to increased food portion sizes, palatability and/or energy‐density of foods, alongside the many social and psychological cues to eat. In this context, and as findings on the health effects of snacking are conflicting, the question remains as to whether more frequent eating and snacking can be of benefit to health. Snacks, if added to habitual meal intake, with no compensation for snack energy contribution, are likely over time to lead to positive energy balance. Hence, snacking might be a contributing factor to the obesity epidemic, in addition to more established factors, such as food choice and physical activity. This paper explores the existing evidence concerning the impact of snacking on bodyweight and the behavioural and metabolic response to snacking. The impact of snacking on cognitive function is also discussed. The review highlights the need for further research as, despite many years of scientific interest in snacking, the lack of consistency in study design and snacking definitions and the array of potential confounding factors (e.g. physical activity levels) makes interpretation of findings difficult and has led to little consensus about the optimum number and composition of meals and/or snacks for bodyweight control, health and wellbeing on a population‐wide basis.