Nutrition Bulletin

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.

Sustainable diets are proposed as a means to improve public health and food security and to reduce the impact of the food system on the environment. Guidance around sustainable diets includes a reduction of animal products in order to move towards a more plant‐based diet, meaning that plant‐originated foods are a predominant, but not the sole component of a diet. The main principles of a sustainable diet (as provided by the Food and Agriculture Organization of the United Nations/World Health Organization) are to consume a variety of unprocessed or minimally processed foods, mainly as wholegrains, pulses, fruits and vegetables, with moderate amounts of eggs, dairy, poultry and fish and modest amounts of ruminant meat, which are consistent with the current UK healthy eating recommendations (e.g. Eatwell Guide). The aim of this review was twofold: (i) to discuss public health challenges associated with consumers’ knowledge regarding protein sustainability, healthier protein sources and protein requirements, and (ii) to review potential approaches to facilitate the shift towards a more sustainable diet. Consumers would benefit from receiving clear guidance around how much protein is needed to meet their daily requirements. The public health message directed to a consumer could highlight that desired health outcomes, such as muscle protein synthesis and weight control, can be achieved with both sources of protein (i.e. animal and plant‐based), and that what is more important is the nature of the ‘protein package’. Health promotion and education around the benefits of plant‐based protein could be one of the strategies encouraging the wider population to consider a shift towards a predominantly plant‐based diet.

The merits of a fibre‐rich diet are well documented. Resistant starch (RS) is a form of starch that resists digestion in the small intestine and, as such, is classified as a type of dietary fibre. RS can be categorised as one of five types (RS1–5), some of which occur naturally in foods such as bananas, potatoes, grains and legumes and some of which are produced or modified commercially, and incorporated into food products. This review describes human evidence on the health effects of RS consumption, with the aim of identifying any benefits of RS‐rich foods and RS as a functional ingredient. The reduced glycaemic response consistently reported with RS consumption, when compared with digestible carbohydrate, has resulted in an approved European Union health claim. Thus, RS‐rich foods may be particularly useful for managing diabetes. There appears to be little impact of RS on other metabolic markers, such as blood pressure and plasma lipids, though data are comparatively limited. Promising results on markers of gut health suggest that further research may lead to the classification of RS as a prebiotic. Microbial fermentation of RS in the large intestine to produce short‐chain fatty acids likely underpins some of its biological effects, including increasing satiety. However, effects on appetite have not resulted in notable changes in bodyweight after long‐term consumption. Emerging research suggests potential for RS as an ingredient in oral rehydration solutions and in the treatment of chronic kidney disease. Overall, RS possesses positive properties as a healthy food component.

Personalised nutrition can be defined as developing unique nutrition guidelines for each individual; precision nutrition seeks to develop effective approaches based on the combination of an individual's genetic, environmental and lifestyle factors. The former infers variants that underlie traits are largely fixed (i.e. stable across time) and appeals to the notion that we are inherently different from one another. The latter opens up the possibility that what we do and where we are may be more important than what we are. While there are undoubtedly a specific minority of individuals who clearly require a more personalised approach to nutrition, several criteria must be fulfilled before we can justify or implement personalised nutrition for the general population. These would include identifying a desired health outcome and a valid predictor of how that outcome changes, which can be measured with sufficient accuracy and exhibit a robust correlation and/or causal relationship in the required direction (i.e. predictor‐response). Many attempts to personalise nutrition, such as profiling the genome or microbiome, do not currently meet all these criteria. Therefore, we argue that there is presently insufficient rationale for truly personalised nutrition for the majority of people based on the inter‐individual differences that separate them. Conversely, we propose that precision nutrition based on the environmental and/or behavioural ‘lifestyle’ variance within each person may provide a more effective basis for adjusting diet dynamically, with recognition of varying physiological demands and requirements over time.