Overconsumption of free sugars, particularly from sugar-sweetened beverages (SSB), has potential negative health impacts. Implementation of a range of public health strategies is needed to reduce intakes of free sugars, including reducing portion sizes, promoting healthier dietary choices and reformulating foods and beverages. Although low-calorie sweeteners (LCS) are a useful tool for reducing energy intake and control glucose response when consuming sweet foods and drinks, several opinions persist about the adverse health effects of LCS, many of which are based on poor, little or no scientific evidence. This symposium report summarises key messages of the presentations and related discussions delivered at a scientific symposium at the 13th European Nutrition Conference (FENS 2019). These presentations considered the scientific evidence and current recommendations about the use and potential benefits of LCS for human health, with a particular focus on current evidence in relation to body weight and glycaemic control. Many of the studies to date on LCS have focused on low-calorie sweetened beverages (LCSB); however, the psychological and behavioural factors influencing consumer beliefs and consumption of LCSB need to be further explored. Current recommendations for LCS use are described, including the conclusions from a recent expert consensus report identifying the challenges that remain with LCS research. Finally, existing knowledge gaps and future actions are described, as well as two large ongoing research projects: SWITCH and SWEET.

New dietary-based concepts are needed for treatment and effective prevention of overweight and obesity. The primary objective was to investigate if reduction in appetite is associated with improved weight loss maintenance. This cohort study was nested within the European Commission project Satiety Innovation (SATIN). Participants achieving ≥8% weight loss during an initial 8-week low-energy formula diet were included in a 12-week randomised double-blind parallel weight loss maintenance intervention. The intervention included food products designed to reduce appetite or matching controls along with instructions to follow national dietary guidelines. Appetite was assessed by ad libitum energy intake and self-reported appetite evaluations using visual analogue scales during standardised appetite probe days. These were evaluated at the first day of the maintenance period compared with baseline (acute effects after a single exposure of intervention products) and post-maintenance compared with baseline (sustained effects after repeated exposures of intervention products) regardless of randomisation. A total of 181 participants (forty-seven men and 134 women) completed the study. Sustained reduction in 24-h energy intake was associated with improved weight loss maintenance (R 0·37; P = 0·001), whereas the association was not found acutely (P = 0·91). Suppression in self-reported appetite was associated with improved weight loss maintenance both acutely (R −0·32; P = 0·033) and sustained (R −0·33; P = 0·042). Reduction in appetite seems to be associated with improved body weight management, making appetite-reducing food products an interesting strategy for dietary-based concepts.

Reducing food portion size could reduce energy intake. However, it is unclear at what point consumers respond to reductions by increasing intake of other foods. We predicted that a change in served portion size would only result in significant additional eating within the same meal if the resulting portion size was no longer visually perceived as ‘normal’. Participants in two crossover experiments (Study 1: n 45; Study 2: n 37; adults, 51 % female) were served different-sized lunchtime portions on three occasions that were perceived by a previous sample of participants as ‘large-normal’, ‘small-normal’ and ‘smaller than normal’, respectively. Participants were able to serve themselves additional helpings of the same food (Study 1) or dessert items (Study 2). In Study 1 there was a small but significant increase in additional intake when participants were served the ‘smaller than normal’ compared with the ‘small-normal’ portion (m difference = 161 kJ, P = 0·002, d = 0·35), but there was no significant difference between the ‘small-normal’ and ‘large-normal’ conditions (m difference = 88 kJ, P = 0·08, d = 0·24). A similar pattern was observed in Study 2 (m difference = 149 kJ, P = 0·06, d = 0·18; m difference = 83 kJ, P = 0·26, d = 0·10). However, smaller portion sizes were each associated with a significant reduction in total meal intake. The findings provide preliminary evidence that reductions that result in portions appearing ‘normal’ in size may limit additional eating, but confirmatory research is needed.

Due to regulatory changes, fast food companies often depict healthy foods in their television advertisements to children. The present study examined how exposure to advertising for ‘healthy’ meal bundles to children influenced the selection of food in children. A total of fifty-nine children (thirty-seven males) aged 7–10 years (8·8 (sd 0·9) years) took part in the present study. The within-participant, counterbalanced design had two conditions: control (exposure to ten toy adverts across two breaks of five adverts each) and experimental (the middle advert in each break replaced with one for a McDonald's Happy Meal® depicting the meal bundle as consisting of fish fingers, a fruit bag and a bottle of mineral water). Following viewing of the adverts embedded in a cartoon, children completed a hypothetical menu task that reported liking for McDonald's food and fast food, in general. Nutritional knowledge, height and weight of the children were measured. There was no significant difference between the two advert conditions for the nutritional content of the meal bundles selected. However, children's liking for fast food, in general, increased after exposure to the food adverts relative to control (P= 0·004). Compared to children with high nutritional knowledge, those with low scores selected meals of greater energy content (305 kJ) after viewing the food adverts (P= 0·016). Exposure to adverts for ‘healthy’ meal bundles did not drive healthier choices in children, but did promote liking for fast food. These findings contribute to debates about food advertising to children and the effectiveness of related policies.

Nutrition across the lifespan encompasses both preventative and treatment options to maintain health and vitality. This review will focus on the challenge of overconsumption of energy relative to energy expenditure and the consequent development of overweight and obesity, since they are responsible for much of the burden of chronic disease in the developed world. Understanding the mechanisms of hunger and satiety and how particular foodstuffs and nutrients affect appetite and motivation to eat is important for evidence-based interventions to achieve weight control and design of community-wide dietary strategies that reach across the lifespan. Food reformulation for appetite control and weight management requires a knowledge of the mechanisms of hunger and satiety, how food interacts with peripheral and central regulatory systems, and how these interactions change across the lifecourse, allied to the technical capability to generate, evaluate and develop new ingredients and foods with enhanced biological potency based on these mechanisms. Two European Union-funded research projects, Full4Health and SATIN, are adopting these complementary approaches. These research projects straddle the sometimes conflicted ground between justifiable public health concerns on the one hand and the food and drink industry on the other. These multi-disciplinary projects pull together expertise in nutrition, neuroimaging, psychology and food technology that combines with food industry partners to maximise expected impact of the research. Better knowledge of mechanisms regulating hunger/satiety will lead to evidence base for preventive strategies for the European population, to reduction of chronic disease burden and to increased competitiveness of European food industry through the development of new food products.

The current review considers satiety-based approaches to weight management in the context of health claims. Health benefits, defined as beneficial physiological effects, are what the European Food Safety Authority bases their recommendations on for claim approval. The literature demonstrates that foods that target within-meal satiation and post-meal satiety provide a plausible approach to weight management. However, few ingredient types tested produce the sustainable and enduring effects on appetite accompanied by the necessary reductions in energy intake required to claim satiety/reduction in hunger as a health benefit. Proteins, fibre types, novel oils and carbohydrates resistant to digestion all have the potential to produce beneficial short-term changes in appetite (proof-of-concept). The challenge remains to demonstrate their enduring effects on appetite and energy intake, as well as the health and consumer benefits such effects provide in terms of optimising successful weight management. Currently, the benefits of satiety-enhancing ingredients to both consumers and their health are under researched. It is possible that such ingredients help consumers gain control over their eating behaviour and may also help reduce the negative psychological impact of dieting and the physiological consequences of energy restriction that ultimately undermine weight management. In conclusion, industry needs to demonstrate that a satiety-based approach to weight management, based on single-manipulated food items, is sufficient to help consumers resist the situational and personal factors that drive overconsumption. Nonetheless, we possess the methodological tools, which when employed in appropriate designs, are sufficient to support health claims.