This study examined whether supplementation with collagen peptides (CP) affects appetite and post-exercise energy intake in healthy active females. In this randomised, double-blind cross-over study, fifteen healthy females (23 (sd 3) years) consumed 15 g/d of CP or a taste matched non-energy control (CON) for 7 d. On day 7, participants cycled for 45 min at ∼55 % Wmax, before consuming the final supplement. Sixty-min post supplementation an ad libitum meal was provided, and energy intake recorded. Subjective appetite sensations were measured daily for 6 d (pre- and 30 min post-supplement) and pre (0 min) to 280 min post-exercise on day 7. Blood glucose and hormone concentrations (total ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY), cholecystokinin (CCK), dipeptidyl peptidase-4 (sDPP-4), leptin, and insulin) were measured fasted at baseline (day 0), then pre-breakfast (0 min), post-exercise (100 min), post-supplement (115, 130, 145, 160 min) and post-meal (220, 280 min) on day 7. Ad libitum energy intake was ∼10 % (∼41 kcal) lower in the CP trial (P = 0·037). There was no difference in gastrointestinal symptoms or subjective appetite sensations throughout the trial (P ≥ 0·412). Total plasma GLP-1 (AUC, CON: 6369 (sd 2330); CP: 9064 (sd 3021) pmol/l; P < 0·001) and insulin (+80 % at peak) were higher after CP (P < 0·001). Plasma ghrelin and leptin were lower in CP (condition effect; P ≤ 0·032). PYY, CCK and glucose were not different between CP and placebo (P ≥ 0·100). CP supplementation following exercise increased GLP-1 and insulin concentrations and reduced ad libitum energy intake at a subsequent meal in physically active females.

My research on dietary protein and the regulation of proteostasis in muscle and the whole body during growth and adult maintenance is reviewed. Growth control involves both permissive and regulatory roles of protein acting with genetic determinants and functional demand, to mediate substrate flow into metabolic consumption, energy storage and growth. In 1995 a Protein-Stat hierarchical model for control of the fat-free mass was proposed and is updated here with special emphasis on the skeletal muscle mass. Control is exerted in large part through a central aminostatic appetite mechanism sensing changes in free amino-acid patterns in response to the balance between their supply in relation to their demand. This acts primarily to maintain skeletal muscle mass at a level set by the linear dimensions of the organism, which in turn is controlled by genetic programming and mediated by the developmental hormones acting together with an appropriate anabolic drive deriving from dietary protein. This, together with other important nutrients like zinc, calcium and vitamin D, provides the regulatory stimulus for growth and protein deposition in all tissues. The applicability of this model to childhood growth and development will be described as well as the maintenance of the adult phenotypic muscle mass within populations with protein intakes varying over a wide range, work which resulted in an adaptive metabolic demand model for protein and amino acid requirements and values for apparent adult protein and lysine requirements. Finally current understanding of aminostatic mechanisms of amino-acid sensing in the brain will be reviewed.

The aim of this randomised controlled trial was to investigate the effects of breakfast high or low in protein on body composition and cardiometabolic markers in young women with overweight. In total, fifty-six women aged 18–30 years consumed a breakfast containing either high protein (34 g protein, n 26) or low protein (6 g protein, n 30) for 12 weeks. Measurements of body composition by dual-energy X-ray absorptiometry, waist circumference, glucose tolerance, fasting glucose, insulin and lipid profile were performed before and after this period. The primary outcome was fat mass. Satiety and hunger were evaluated by self-reported Visual Analogue Scale (VAS) scores. Dietary intake was estimated by 4-d dietary records, and calcium intake was estimated by FFQ. At baseline, relative daily protein intake was 15·2 ± 2·8 E%, which increased to 19·3 ± 3·4 E% in high protein but was unchanged in low protein (P < 0·001 between groups). High protein reported higher satiety compared with low protein (P = 0·02). Yet, no group differences were observed in changes in energy intake, body composition, blood lipid profile or measures of glucose tolerance (all P > 0·10). However, bone mineral content tended to increase in high protein (P = 0·05) and decrease in low protein (P = 0·07, interaction effect: P = 0·01). Conclusively, a high v. low content of protein in breakfast increased satiety but did not affect body composition or cardiometabolic markers in young women with overweight. This study adds to the sparse evidence on the effects of breakfast with different macronutrient compositions on health parameters in women with overweight. Registered at clinicaltrials.gov: NCT04518605.

Australian Aboriginal and Torres Strait Islander peoples are disproportionately affected by diet-related disease such as type 2 diabetes, the rate of which is 20 fold higher than that of non-Indigenous young Australians(1). Before colonisation, Gomeroi and other First Nations people harvested, threshed and ground native grass seeds with water into a paste before cooking(2). The introduction of white refined flour has meant that time-consuming grass seed processing has mainly ceased, and native grains are no longer eaten habitually. The aim of this study was to determine the effect of 10% incorporation of two native grain flours on postprandial blood glucose response and Glycemic Index (GI). Five male and five female subjects, with a mean age of 30 ± 0.9 and BMI of 21.6 ± 0.4 and normoglycemic, participated in GI testing of three flour + water pancake compositions matched for available carbohydrate: 100% wheat (Wheat) and 90% wheat:10% native grains (Native_a and Native_b). Effect on satiety was determined using subjective ratings of hunger/fullness over the time course of the GI testing. In comparison to the plain flour pancake, replacing 10% plain wheat flour with Native_b flour significantly reduced the GI by 28.8% from 73 ± 5 to 48 ± 5, having a profound effect on postprandial blood glucose levels in 9 of 10 subjects (p<0.05, paired t-test). The GI of 10% Native_a flour pancake was not different from 100% wheat flour pancake (75 ± 5). Satiety tended to be greater when native grains were incorporated but this study was not powered to detect effect on satiety. In conclusion, replacing only 10% of plain wheat flour with Native_b flour was sufficient to significantly reduce the blood glycemic response to the pancake. This replacement could be easily implemented for prevention and treatment of type 2 diabetes. For Aboriginal people with access to grain Country, the nutritional health benefits associated with eating native grains, as well as the cultural benefits of caring for Country, will have a direct transformational impact on local communities. Our vision is to revitalise Gomeroi grains and to guide a sustainable Indigenous-led industry to heal Country and people through co-designed research.

Energy deficit is common during prolonged periods of strenuous physical activity and limited sleep, but the extent to which appetite suppression contributes is unclear. The aim of this randomised crossover study was to determine the effects of energy balance on appetite and physiological mediators of appetite during a 72-h period of high physical activity energy expenditure (about 9·6 MJ/d (2300 kcal/d)) and limited sleep designed to simulate military operations (SUSOPS). Ten men consumed an energy-balanced diet while sedentary for 1 d (REST) followed by energy-balanced (BAL) and energy-deficient (DEF) controlled diets during SUSOPS. Appetite ratings, gastric emptying time (GET) and appetite-mediating hormone concentrations were measured. Energy balance was positive during BAL (18 (sd 20) %) and negative during DEF (–43 (sd 9) %). Relative to REST, hunger, desire to eat and prospective consumption ratings were all higher during DEF (26 (sd 40) %, 56 (sd 71) %, 28 (sd 34) %, respectively) and lower during BAL (–55 (sd 25) %, −52 (sd 27) %, −54 (sd 21) %, respectively; Pcondition < 0·05). Fullness ratings did not differ from REST during DEF, but were 65 (sd 61) % higher during BAL (Pcondition < 0·05). Regression analyses predicted hunger and prospective consumption would be reduced and fullness increased if energy balance was maintained during SUSOPS, and energy deficits of ≥25 % would be required to elicit increases in appetite. Between-condition differences in GET and appetite-mediating hormones identified slowed gastric emptying, increased anorexigenic hormone concentrations and decreased fasting acylated ghrelin concentrations as potential mechanisms of appetite suppression. Findings suggest that physiological responses that suppress appetite may deter energy balance from being achieved during prolonged periods of strenuous activity and limited sleep.

High-protein meals and foods are promoted for their beneficial effects on satiety, weight loss and glucose homeostasis. However, the mechanisms involved and the long-term benefits of such diets are still debated. We here review how the characterisation of intestinal gluconeogenesis (IGN) sheds new light on the mechanisms by which protein diets exert their beneficial effects on health. The small intestine is the third organ (in addition to the liver and kidney) contributing to endogenous glucose production via gluconeogenesis. The particularity of glucose produced by the intestine is that it is detected in the portal vein and initiates a nervous signal to the hypothalamic nuclei regulating energy homeostasis. In this context, we demonstrated that protein diets initiate their satiety effects indirectly via IGN and portal glucose sensing. This induction results in the activation of brain areas involved in the regulation of food intake. The μ-opioid-antagonistic properties of protein digests, exerted in the portal vein, are a key link between IGN induction and protein-enriched diet in the control of satiety. From our results, IGN can be proposed as a mandatory link between nutrient sensing and the regulation of whole-body homeostasis. The use of specific mouse models targeting IGN should allow us to identify several metabolic functions that could be controlled by protein diets. This will lead to the characterisation of the mechanisms by which protein diets improve whole-body homeostasis. These data could be the basis of novel nutritional strategies targeting the serious metabolic consequences of both obesity and diabetes.

This brief report summarises a framework for understanding satiety presented at the 13th European Nutrition Conference, FENS 2019 – Malnutrition in an Obese World: European Perspectives. Aspects of satiety phenotyping and role of food hedonics in satiation are considered in the context of appetite control and obesity. Almonds are evaluated for their unique composition and structure which affect their behaviour in the human gastrointestinal tract. Their role in appetite control and management of satiety has been explored.

Resistant maltodextrin (RMD) from various sources of starch has been extensively studied. However, studies which reported the effects of tapioca RMD (TRM) on glucose and insulin response are lacking. This study investigated the effect of TRM on postprandial plasma glucose and serum insulin in healthy subjects. Additionally, satiety and gastrointestinal tolerability were also evaluated. Sixteen healthy participants received five different treatments on five separate days. Participants received 50 g of either: glucose (GL), tapioca maltodextrin (TM), TRM, MIX15% (7⋅5 g TRM + 42⋅5 g TM) or MIX50% (25 g TRM + 25 g TM). Plasma glucose, serum insulin and subjective appetite responses were measured postprandially over 180 min. Gastrointestinal symptoms were evaluated by questionnaire before and after each test day. Results showed that at 30 min after treatment drinks, plasma glucose after TRM was significantly lowest (104⋅60 (sem 2⋅63 mg/dl) than after GL (135⋅87 (sem 4⋅88) mg/dl; P <0⋅001), TM (127⋅93 (sem 4⋅05) mg/dl; P = 0⋅001), MIX15% (124⋅67 (sem 5⋅73) mg/dl; P = 0⋅039) and MIX50% (129⋅33 (sem 5⋅23) mg/dl; P = 0⋅003) (1 mg/dl = 0⋅0555 mmol/l). In addition, TRM also significantly reduced serum insulin (13⋅01 (sem 2⋅12) μIU/ml) compared with GL (47⋅90 (sem 11⋅93) μIU/ml; P = 0⋅013), TM (52⋅96 (sem 17⋅68) μIU/ml; P = 0⋅002) and MIX50% (33⋅16 (sem 4⋅99) μIU/ml; P = 0⋅008). However, there were no significant differences in subjective appetite between treatments (P > 0⋅05). A single high dose of TRM (50 g) caused flatulence (P < 0⋅05). Tapioca resistant maltodextrin has low digestibility in the small intestine and, therefore, reduced incremental plasma glucose and serum insulin, without affecting satiety in healthy subjects over 180 min. Gastrointestinal tolerability of TRM should be considered when consumed in high doses.

This review seeks to synthesise our knowledge about changes in hunger and satiety that occur during diet-induced weight loss and during weight loss maintenance, with a particular focus on youth with obesity. Mechanisms of appetite responses to weight loss rely heavily on the adult literature. Physiological mechanisms that control appetite and satiety via the gut–brain axis have been elucidated but we have an incomplete picture of changes in gut hormones and peptides in youth with obesity. In adolescents, the role of the brain in long-term sensing of body composition and modifying appetite and satiety changes is easily over-ridden by hedonic influences for the reward of highly palatable sweet foods and encourages over-consumption. Accordingly, reward cues and hyper-responsiveness to palatable foods lead to a pattern of food choices. Different reward systems are necessary that are substantial enough to reward the continued individual effort required to sustain new behaviours, that need to be adopted to support a reduced body weight. Periods of growth and development during childhood provide windows of opportunity for interventions to influence body weight trajectory but long-term studies are lacking. More emphasis needs to be placed on anticipatory guidance on how to manage powerful hedonic influences of food choice, essential to cope with living in our obesogenic environment and managing hunger which comes with the stronger desire to eat after weight has been lost.

Generating feelings of satiety may be important in maintaining weight control. It has been hypothesised that the circulating concentration of glucose is a major determinant of satiety, yet the relationship between postprandial glycaemia and satiety is inconclusive. Our aim was to assess satiety following ingestion of beverages differing in glycaemic index (GI) containing either 50 g of sucrose (GI 65) or isomaltulose (PalatinoseTM) (GI 32). The beverages were matched for sweetness using a triangle sensory test. Seventy-seven participants were randomised to the order in which they received each beverage, 2 weeks apart. A standard lunch was given at 12.00 hours. Satiety was measured using 100-mm visual analogue scales (VAS) administered at 14.00 hours (baseline) and at 30, 60, 90, 120, 150 and 180 min after ingesting the beverage. Weighed diet records were kept from 17.00 to 24.00 hours. Mean differences for isomaltulose compared with sucrose AUC VAS were ‘How hungry do you feel?’ 109 (95 % CI –443, 661) mm × min; ‘How satisfied do you feel?’ 29 (95 % CI –569, 627) mm × min; ‘How full do you feel?’ −91 (95 % CI –725, 544) mm × min and ‘How much do you think you can eat?’ 300 (95 % CI –318, 919) mm × min. There was no between-treatment difference in satiety question responses or in dietary energy intake −291 (95 % CI −845, 267) kJ over the remainder of the day. In this experiment, feelings of satiety were independent of the GI of the test beverages. Any differences in satiety found between foods chosen on the basis of GI could be attributable to food properties other than the glycaemic-inducing potential of the food.

Knowing the biological signals associated with appetite control is crucial for understanding the regulation of food intake. Biomarkers of appetite have been defined as physiological measures that relate to subjective appetite ratings, measured food intake, or both. Several metabolites including amino acids, lipids and glucose were proposed as key molecules associated with appetite control over 60 years ago, and along with bile acids are all among possible appetite biomarker candidates. Additional metabolites that have been associated with appetite include endocannabinoids, lactate, cortisol and β-hydroxybutyrate. However, although appetite is a complex integrative process, studies often investigated a limited number of markers in isolation. Metabolomics involves the study of small molecules or metabolites present in biological samples such as urine or blood, and may present a powerful approach to further the understanding of appetite control. Using multiple analytical techniques allows the characterisation of molecules, such as carbohydrates, lipids, amino acids, bile acids and fatty acids. Metabolomics has proven successful in identifying markers of consumption of certain foods and biomarkers implicated in several diseases. However, it has been underexploited in appetite control or obesity. The aim of the present narrative review is to: (1) provide an overview of existing metabolites that have been identified in human biofluids and associated with appetite control; and (2) discuss the potential of metabolomics to deepen understanding of appetite control in humans.

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.

The present study examined whether the combination of medium-chain TAG (MCT) along with exercise suppresses energy intake to a greater extent compared with either intervention alone. Twelve participants consumed a porridge breakfast containing 692·9 kJ of either vegetable or MCT oil on two separate occasions: one followed by rest for 240 min and another followed by rest broken up with 1 h of cycling at 65 % $\dot V$O2peak starting at 120 min. At 240 min, participants consumed a buffet lunch to satiation and recorded their food intake for the rest of the day. Expired air samples (for calculation of energy expenditure (EE)) and subjective ratings of appetite on visual analogue scales were taken every 30 min, and gastric emptying (GE) breath samples were taken every 15 min. No effect of either breakfast or exercise condition was observed on energy intake at any time point (P > 0·05) or no effect was observed on subjective appetite ratings (P > 0·05). Exercise trials resulted in significantly higher EE compared with resting trials (2960·6 kJ, 95 % CI 2528·9, 3392·2; P < 0·001), and MCT increased resting EE over 4 h compared with long-chain TAG (LCT) (124·8 kJ, 95 % CI 13·5, 236·0; P = 0·031). GE was accelerated by exercise, regardless of the breakfast consumed, but delayed by MCT in both resting and exercise trials. The results show that exercise causes energy deficits via increased EE without promoting dietary compensation. MCT has no effect on energy intake or satiety but increases EE under resting conditions. There is no additive effect of MCT and exercise on EE, intake or appetite ratings.

Grains rich in starch constitute the primary source of energy for both pigs and humans, but there is incomplete understanding of physiological mechanisms that determine the extent of digestion of grain starch in monogastric animals including pigs and humans. Slow digestion of starch to produce glucose in the small intestine (SI) leads to undigested starch escaping to the large intestine where it is fermented to produce short-chain fatty acids. Glucose generated from starch provides more energy than short-chain fatty acids for normal metabolism and growth in monogastrics. While incomplete digestion of starch leads to underutilised feed in pigs and economic losses, it is desirable in human nutrition to maintain consistent body weight in adults. Undigested nutrients reaching the ileum may trigger the ileal brake, and fermentation of undigested nutrients or fibre in the large intestine triggers the colonic brake. These intestinal brakes reduce the passage rate in an attempt to maximise nutrient utilisation, and lead to increased satiety that may reduce feed intake. The three physiological mechanisms that control grain digestion and feed intake are: (1) gastric emptying rate; (2) interplay of grain digestion and passage rate in the SI controlling the activation of the ileal brake; and (3) fermentation of undigested nutrients or fibre in the large intestine activating the colonic brake. Fibre plays an important role in influencing these mechanisms and the extent of their effects. In this review, an account of the physiological mechanisms controlling the passage rate, feed intake and enzymatic digestion of grains is presented: (1) to evaluate the merits of recently developed methods of grain/starch digestion for application purposes; and (2) to identify opportunities for future research to advance our understanding of how the combination of controlled grain digestion and fibre content can be manipulated to physiologically influence satiety and food intake.

Oligofructose is a prebiotic dietary fibre obtained from chicory root inulin. Oligofructose supplementation may affect satiety, food intake, body weight and/or body composition. The aim was to examine the efficacy of oligofructose-supplemented granola bars on the following weight management outcomes: satiety, energy intake, body weight and body composition in overweight or obese adults. In all, fifty-five adults with overweight or obesity (thirty-six females/nineteen males; age: 41 (sd 12) years; 90·6 (sd 11·8) kg; BMI: 29·4 (sd 2·6) kg/m2) participated in a parallel, triple-blind, placebo-controlled intervention. A total of twenty-nine subjects replaced their snacks twice a day with an equienergetic granola bar supplemented with 8 g of oligofructose (OF-Bar). Subjects in the control group (n 26) replaced their snack with a control granola bar without added oligofructose (Co-Bar). Satiety, 24-h energy intake, body weight and body composition (fat mass and waist circumference) were measured at baseline, weeks 6 and 12. In addition, weekly appetite and gastrointestinal side effects were measured. During the intervention, energy intake, body weight and fat mass remained similar in the Co-Bar and OF-Bar groups (all P>0·05). Both groups lost 0·3 (sd 1·2) kg lean mass (P<0·01) and reduced their waist circumference with −2·2 (sd 3·6) cm (P<0·0001) after 12 weeks. The OF-Bar group reported decreased hunger in later weeks of the intervention (P=0·04), less prospective food consumption (P=0·03) and less thirst (P=0·003). To conclude, replacing daily snacks for 12 weeks with oligofructose-supplemented granola bars does not differentially affect energy intake, body weight and body composition compared with a control bar. However, there was an indication that appetite was lower after oligofructose bar consumption.

Manipulation of food's macronutrient composition in order to reduce energy content without compromising satiating capacity may be helpful in body weight control. For cheeses, substituting fat with protein may provide such opportunity. We aimed at examining the acute effect of cheeses with different macronutrient compositions on accumulated energy intake and subjective appetite sensation. A total of thirty-nine normal-weight (average BMI 24·4 kg/m2) men and women completed the partly double-blind, randomised crossover study with high-protein/low-fat (HP/LF, 696 kJ), high-protein/high-fat (HP/HF, 976 kJ) and low-protein/high-fat (LP/HF, 771 kJ) cheeses. After overnight fasting, 80 g cheese were served with 70 g bread, 132 g juice and 125 g coffee/tea/water. Ad libitum spaghetti bolognaise was served after 3 h and energy intake assessed. Subjective appetite ratings were assessed using visual analogue scales. Composite appetite scores were calculated and evaluated relatively to energy intake. Total accumulated energy intake was 188·3 (se 97·4) kJ lower when consuming the HP/LF compared with the HP/HF (P ≤ 0·05), but, compared with the LP/HF cheese, the difference was not significant (177·0 (se 100·4) kJ lower; P = 0·08). In relation to energy intake, the composite appetite score was lower when consuming the HP/LF compared with the HP/HF (P = 0·003) and the LP/HF (P = 0·007) cheeses. Thereby, no compensatory eating following consumption of the HP/LF compared with the HP/HF cheese was found. The HP/LF cheese resulted in an increased feeling of satiety in relation to its lower energy content compared with both HP/HF and LP/HF cheeses.

A better understanding of the factors that influence eating behaviour is of importance as our food choices are associated with the risk of developing chronic diseases such as obesity, CVD, type 2 diabetes or some forms of cancer. In addition, accumulating evidence suggests that the industrial food production system is a major contributor to greenhouse gas emission and may be unsustainable. Therefore, our food choices may also contribute to climate change. By identifying the factors that influence eating behaviour new interventions may be developed, at the individual or population level, to modify eating behaviour and contribute to society’s health and environmental goals. Research indicates that eating behaviour is dictated by a complex interaction between physiology, environment, psychology, culture, socio-economics and genetics that is not fully understood. While a growing body of research has identified how several single factors influence eating behaviour, a better understanding of how these factors interact is required to facilitate the developing new models of eating behaviour. Due to the diversity of influences on eating behaviour this would probably necessitate a greater focus on multi-disciplinary research. In the present review, the influence of several salient physiological and environmental factors (largely related to food characteristics) on meal initiation, satiation (meal size) and satiety (inter-meal interval) are briefly discussed. Due to the large literature this review is not exhaustive but illustrates the complexity of eating behaviour. The present review will also highlight several limitations that apply to eating behaviour research.

Whole-grain rye foods reduce appetite, insulin and sometimes glucose responses. Increased gut fermentation and plant protein may mediate the effect. The aims of the present study were to investigate whether the appetite-suppressing effects of whole-grain rye porridge could be enhanced by replacing part of the rye with fermented dietary fibre and plant protein, and to explore the role of gut fermentation on appetite and metabolic responses over 8 h. We conducted a randomised, cross-over study using two rye porridges (40 and 55 g), three 40-g rye porridges with addition of inulin:gluten (9:3; 6:6; 3:9 g) and a refined wheat bread control (55 g), served as part of complete breakfasts. A standardised lunch and an ad libitum dinner were served 4 and 8 h later, respectively. Appetite, breath hydrogen and methane, glucose, insulin and glucagon-like peptide-1 (GLP-1) responses were measured over 8 h. Twenty-one healthy men and women, aged 23–60 years, with BMI of 21–33 kg/m2 participated in this study. Before lunch, the 55-g rye porridges lowered hunger by 20 % and desire to eat by 22 % and increased fullness by 29 % compared with wheat bread (P<0·05). Breath hydrogen increased proportionally to dietary fibre content (P<0·05). Plasma glucose after lunch was 6 % lower after the 55-g rye porridges compared with wheat bread (P<0·05) and correlated to breath hydrogen (P<0·001). No differences were observed in ad libitum food intake, insulin or GLP-1. We conclude that no further increase in satiety was observed when replacing part of the rye with inulin and gluten compared with plain rye porridges.

Health nudge interventions to steer people into healthier lifestyles are increasingly applied by governments worldwide, and it is natural to look to such approaches to improve health by altering what people choose to eat. However, to produce policy recommendations that are likely to be effective, we need to be able to make valid predictions about the consequences of proposed interventions, and for this, we need a better understanding of the determinants of food choice. These determinants include dietary components (e.g. highly palatable foods and alcohol), but also diverse cultural and social pressures, cognitive-affective factors (perceived stress, health attitude, anxiety and depression), and familial, genetic and epigenetic influences on personality characteristics. In addition, our choices are influenced by an array of physiological mechanisms, including signals to the brain from the gastrointestinal tract and adipose tissue, which affect not only our hunger and satiety but also our motivation to eat particular nutrients, and the reward we experience from eating. Thus, to develop the evidence base necessary for effective policies, we need to build bridges across different levels of knowledge and understanding. This requires experimental models that can fill in the gaps in our understanding that are needed to inform policy, translational models that connect mechanistic understanding from laboratory studies to the real life human condition, and formal models that encapsulate scientific knowledge from diverse disciplines, and which embed understanding in a way that enables policy-relevant predictions to be made. Here we review recent developments in these areas.