Anorexia of ageing - the age-related reduction in appetite and food intake - is a public health concern for an ageing global population. However, current understanding of the aetiology of the condition is limited. In this review, evidence of gut hormone responses to feeding in older adults is reviewed, and it is proposed that a dysregulation of this process is a mechanism driving low appetite in later life. The evidence is synthesised to critically present this case, spotlighting recent data demonstrating a highly anorexigenic gut hormone profile in older adults exhibiting low appetite, which is not observed in older adults exhibiting a 'healthy' appetite. These findings and this theory are interrogated with an appreciation that appetite control is complex and multifactorial, not least in the context of anorexia of ageing; it is posited that changes in gut hormone secretions are a mechanism rather than the mechanism, but propose that this may explain certain presentations of anorexia of ageing. The current knowledge base is contextualised for practical implications and priorities for future research are highlighted.

The importance of micronutrient status in human food choice remains a fundamental issue needing further investigation. The objectives of the present paper are to present and discuss historic and current research together with a general model incorporating this interaction and to suggest future research to address the questions this poses. By definition, essential nutrients must be consumed in sufficient amounts to meet an individual’s requirements. While data indicate that complex neuroendocrine mechanisms provide negative-feedback control of energy and protein intake to support homeostasis, corresponding mechanisms controlling micronutrient intake are less well studied. In some contexts, they are explicitly assumed to be absent, specifically for models evaluating safety and risks of deficiencies. However, it may be hypothesized that for at least some micronutrients, mechanisms exist that aid attainment of requirements by altering preference for micronutrient-rich foods so as to increase ingestion of foods containing them, similar to how being thirsty increases the appeal of watermelon compared with dry food. If this hypothesis is correct, it may hold important implications for understanding the types and quantities of foods ingested. Greater appeal in foods richer in essential nutrients may reduce the risk of malnutrition. However, by extension, it may be posited that the use of supplements could confound the most healthful food choices. For example, obtaining vitamin C from supplements or fortified foods could then causally reduce the dietary intake of vegetables and fruits by reducing the appeal of these foods. The unintended consequence may be a lower intake of fiber, nitrate, and phytochemicals, food constituents that may contribute to health without being essential nutrients themselves. This hypothesis can and should be tested empirically, for example, through randomized placebo-controlled supplementation trials. If clear causal effects are documented, clinical and public health guidance will require critical evaluation and possible modification.

An international expert panel convened to evaluate nutrition-based approaches to brain health and dementia prevention. This consensus statement integrates perspectives from lived experiences, mechanistic evidence, epidemiology, and clinical interventions. Nutrition plays a crucial role in brain health throughout life and in cognitive decline pathogenesis, particularly through the food-gut-brain axis. Intervention effectiveness varies across the health promotion, prevention, treatment, and maintenance spectrum due to methodological differences and individual responses to nutritional interventions. The Mediterranean and MIND dietary patterns show promise for maintaining cognitive function across studies. Multi-domain interventions like FINGER effectively combine dietary modifications with lifestyle changes to delay dementia onset in at-risk older adults. These findings align with mechanistic evidence on the food-gut-brain axis in maintaining optimal brain health by preventing neurodegeneration. Key mechanisms include gut microbiota composition and function, blood-brain barrier integrity, endothelial and mitochondrial dysfunction, insulin resistance, oxidative stress, and inflammatory processes. Research priorities include standardizing cognitive assessment methodologies, developing early intervention strategies, and implementing integrated precision nutrition and lifestyle approaches. Incorporating patients’ and caregivers’ lived experiences in research co-production was identified as essential to support those with lived experience. The panel concluded that future directions should combine population and individual-level preventive approaches while addressing challenges in sustaining healthy behavioral changes and understanding the complex interplay between diet, lifestyle, and genetic factors in brain health and dementia prevention. Experts emphasized the need for both standardized methodologies and personalized interventions to account for individual variability in nutritional responses and facilitate effective prevention strategies across diverse populations.

Appetite-related hormones are secreted from the gut, signaling the presence of nutrients. Such signaling allows for cross-talk between the gut and the appetite-control regions of the brain, influencing appetite and food intake. As nutritional requirements change throughout the life course, it is perhaps unsurprising that appetite and eating behavior are not constant. Changes in appetite-related gut hormones may underpin these alterations in appetite and eating. In this article, we review evidence of how the release of appetite-related gut hormones changes throughout the life course and how this impacts appetite and eating behaviour. We focus on hormones for which there is the strongest evidence of impact on appetite, food intake, and body weight: the anorexigenic glucagon like peptide-1, peptide tyrosine tyrosine, and cholecystokinin, and the orexigenic ghrelin. We consider hormone concentrations, particularly in response to feeding, from the very early days of life, through childhood and adolescence, where responses may reflect energy requirements to support growth and development. We discuss the period of adulthood and midlife, with a particular focus on sex differences and the effect of menstruation, pregnancy, and menopause, as well as the potential influence of appetite-related gut hormones on body composition and weight status. We then discuss recent advancements in our understanding of how unfavorable changes in appetite-related gut hormone responses to feeding in later life may contribute to undernutrition and a detrimental aging trajectory. Finally, we briefly highlight priorities for future research.

Ageing, which is defined as the progressive deterioration of physiological functions, is an inevitable part of the lifecycle. Nevertheless, its progress is believed to be influenced by modifiable factors, one of the most important being dietary intake. Like many other systems within the human body, detection of nutrients (defined as nutrition sensing), their metabolism, and the body's response to nutrients may change with ageing. There is compelling evidence to suggest that nutrition sensing mechanisms can become dysregulated in certain ageing adults, which can lead to increased morbidity and mortality. However, there is still much to unravel in nutrition sensing and its impact on ageing on multiple levels from molecular signalling to the food environment. We hypothesise that nutrition sensing mechanisms play an important role in the ageing process. To this end, we formed the Ageing and Nutrition Sensing Network to bring together leading multi-disciplinary researchers and early career researchers with expertise across ageing, cell biology, nutrition, epidemiology, and policy. The network aims to address the priority area of health span and quality of life in older age. As a consortium, we defined nutrition sensing and identified five key challenges to be addressed to advance the field of nutrition sensing and ageing. This resulted in the development of four main projects, each one embracing multidisciplinary working and investigating nutrition sensing and ageing from different perspectives. Here we describe our network, our projects, and how we plan to incorporate our findings to promote healthy ageing from science and industry to policy.

Interest in plant-based protein in the UK is increasing due to health, environmental, and ethical considerations. Recent studies have explored how different protein sources impact satiety and related gut hormone responses, with evidence suggesting varied responses between animal-based and plant-based proteins. Skewed protein intake patterns, especially at breakfast, present an opportunity for improving dietary protein distribution in populations who may require increased protein intake but often face appetite reductions. This study determined the acute effect of consuming a plant-based, high protein drink containing 30 g of protein (HPDp); an animal-based, high protein breakfast containing 30 g of protein (HPBa); and a low-protein (10 g), high-carbohydrate breakfast (HCLPB) on satiety hormone responses, subjective appetite and subsequent energy intake in older and younger populations when consumed at breakfast. Eighteen heathy adults completed this within-subject, counterbalanced, cross-over study, (12 under 35 years of age and six over 65 years of age). Measurements for appetite were obtained at baseline, 30, 60, 90, 120, 150, 180, 210 and 240 min, and plasma, GLP-1 and PYY at baseline, 30, 60, 90, 120, 180 min post breakfast consumption. No difference in appetitive responses was found between the HPDp and the energy- and protein-matched HPBa, with both eliciting greater GLP-1 and PYY (both p < 0.004) responses compared with a high carbohydrate, low protein meal. Subjective appetite was also suppressed to a greater extent with HPDp compared with HCLPB (p = 0.001). No differences were observed in ad libitum energy intake.

This study aimed to assess the self-reported frequency and severity of gastrointestinal symptoms (GIS) at rest and around rugby training and match play in male and female rugby union players. An online questionnaire was sent to registered rugby union players (sevens or fifteens). Thirteen GIS were assessed alongside perceptions of appetite around rugby and rest using Likert and visual analog scales. Questions investigating a range of medical and dietary factors were included. Three hundred and twenty-five players (male n=271, female n=54) participated in the study. More frequent GIS (at least one GIS experienced weekly/more often) was reported by players at rest (n=203; 62%) compared to around rugby (n=154; 47%). The overall severity of GIS was low (mild discomfort), but a portion of players (33%) did report symptoms of moderate severity around rugby. Female players reported more frequent and severe symptoms compared to male counterparts (p<0.001). Self-reported appetite was significantly lower after matches compared to training. There were no dietary or medical factors associated with GIS severity scores. This study describes GIS characteristics in male and female rugby union players. Half of the players assessed experienced some form of GIS that may affect nutrition, training, or performance, and should thus be a consideration for practitioners supporting this cohort.

The role of ghrelin metabolism in anorexia of ageing is unclear. The aim of this study was to determine acyl-ghrelin, total ghrelin, and ghrelin O-acyltransferase concentrations when fasted and in responses to feeding in older adults exhibiting anorexia of ageing. Twenty-five older adults (OA; 15f, 74 +/- 7 years, 24.5 kgm(-2)) and twelve younger adults (YA; 6f, 21 +/- 2 years, 24.4 kgm(-2)) provided a fasted measure of subjective appetite and fasted blood sample (0 min) before consuming a standardised porridge breakfast meal (450 kcal). Appetite was measured every 30 min for 240 min and blood was sampled at 30, 60, 90, 120, 180 and 240 min while participants rested. At 240 min, an ad libitum pasta-based lunch meal was consumed. Older adults were identified as those with healthy appetite (HA-OA) or low appetite (LA-OA), based on habitual energy intake, self-report appetite, BMI, and ad libitum lunch intake. YA ate more at lunch (1108 +/- 235 kcal) than HA-OA (653 +/- 133 kcal, p = 0.007) and LA-OA (369 +/- 168 kcal; p < 0.001). LA-OA, but not HA-OA, had higher fasted concentrations of acyl- and total ghrelin than YA (acyl-ghrelin: 621 +/- 307 pgmL(-1) vs. 353 +/- 166 pgmL(-1), p = 0.047; total ghrelin: 1333 +/- 702 pgmL(-1) vs. 636 +/- 251 pgmL(-1), p = 0.006). Acyl-ghrelin (60 min and 90 min) and total ghrelin (90 min) were suppressed to a greater extent for LA-OA than for YA (p < 0.05). No differences were observed in subjective appetite, acyl-to-total ghrelin ratio, or plasma GOAT content (p > 0.1). Higher fasting ghrelin and an augmented ghrelin response to feeding in LA-OA, but not HA-OA, suggests that alterations to ghrelin metabolism are not functions of ageing per se and may be independent causal mechanisms of anorexia of ageing.

Age-related changes in gut hormones may play a role in anorexia of ageing. The aim of this study was to determine concentrations of ghrelin, PYY, and GLP-1 in older adults exhibiting an anorexia of ageing phenotype. Thirteen older adults with healthy appetite (OA-HA; 8f, 75 ± 7 years, 26.0 ± 3.2 kg m-2), fifteen older adults with low appetite (OA-LA; 10f, 72 ± 7 years, 23.6 ± 3.1 kg m-2), and twelve young adults (YA; 6f, 22 ± 2 years, 24.4 ± 2.0 kg m-2) completed the study. Healthy appetite and low appetite were determined based on BMI, habitual energy intake, self-reported appetite, and laboratory-assessed ad libitum lunch intake. Participants provided a fasted measure of subjective appetite and blood sample (0 min) before consuming a standardised breakfast (450 kcal). Appetite was measured and blood samples were drawn throughout a 240-min rest period. At 240 min, an ad libitum lunch meal was consumed. Relative intake at lunch (expressed as percentage of estimated total energy requirement) was lower for OA-LA (19.8 ± 7.7%) than YA (41.5 ± 9.2%, p < 0.001) and OA-HA (37.3 ± 10.0%, p < 0.001). Ghrelin suppression was greater for OA-LA (net AUC, -78719 ± 74788 pg mL-1·240min-1) than both YA (-23899 ± 27733 pg mL-1·240min-1, p = 0.016) and OA-HA (-21144 ± 31161 pg mL-1·240min-1, p = 0.009). There were trends for higher GLP-1 concentrations in OA-LA compared with YA at 90 min (8.85 ± 10.4 pM vs. 1.88 ± 4.63 pM, p = 0.073) and 180 min (5.00 ± 4.71 pM vs. 1.07 ± 2.83 pM, p = 0.065). There was a trend for a greater PYY response for OA-LA compared with OA-HA (net AUC p = 0.062). "Anorexigenic response score" - a composite score of gut hormone responses to feeding - showed greater anorexigenic response in OA-LA, compared with YA and OA-HA. No differences were seen in subjective appetite. These observations suggest augmented anorexigenic responses of gut hormones to feeding may be causal mechanisms of anorexia of ageing.

Glycomacropeptide (GMP) has a unique amino acid profile which may make less satiating than other dietary proteins. This study assessed the feasibility and likely acceptability of a leucine-enriched GMP drink and determined appetite response in older adults (OA). Thirteen OA (11f; 70 ± 4 years) were recruited for sensory assessments of a leucine-enriched GMP drink when mixed with water and with fruit smoothie, compared with whey protein isolate (WHEY). Participants also partook in a single focus group exploring acceptability to protein and supplementation. Separately, a counterbalanced, double-blind study with twelve OA (8f; 69 ± 3 years) was conducted to determine appetite and gut hormone responses. Fasting subjective appetite was recorded using visual analogue scales and a fasted venous blood sample was collected (to measures acyl-ghrelin, PYY, GLP-1, and CCK) before participants consumed either: GMP protein (27g + 3g leucine, 350 mL water), WHEY (30g, 350 mL water), or water. Participants rested for 240 min, with appetite measures and blood sampling throughout. An ad libitum pasta-based meal was then consumed. Sensory testing revealed low pleasantness rating for GMP in water vs. WHEY (16 ± 14 vs 31 ± 24, p = 0.016). GMP addition to smoothie reduced pleasantness (26 ± 21 vs. 61 ± 29, p = 0.009) and worsened the aroma (46 ± 15 vs. 69 ± 28, p = 0.014). The focus group revealed uncertainty of protein needs and a scepticism of supplements, with preference for food. Gut hormone response did not differ between GMP and WHEY (nAUC for all gut hormones p > 0.05). There was no difference between conditions for lunch ad libitum intake (549 ± 171 kcal, 512 ± 238 kcal, 460 ± 199 kcal for GMP, WHEY, and water, p = 0.175), or for subjective appetite response. Leucine-enriched GMP was not less satiating than WHEY, and low palatability and scepticism of supplements question the likely acceptability of GMP supplementation. Providing trusted nutritional advice and food enrichment/fortification may be preferred strategies for increasing protein intake in OA.

Fatty acids are stored within muscle as intramyocellular lipids (IMCL). Some, but not all, studies indicate that following a high fat diet (HFD), IMCL may accumulate and affect insulin sensitivity. This systematic review and meta-analysis aimed to quantify the effects of a HFD on IMCL. It also explored the potential modifying effects of HFD fat content and duration, IMCL measurement technique, physical activity status, and the associations of IMCL with insulin sensitivity. Five databases were systematically searched for studies that examined the effect of ≥3 days of HFD (>35% daily energy intake from fat) on IMCL content in healthy individuals. Meta-regressions were used to investigate associations of the HFD total fat content, duration, physical activity status, IMCL measurement technique, and insulin sensitivity with IMCL responses. Changes in IMCL content and insulin sensitivity (assessed by hyperinsulinemic-euglycemic clamp) are presented as standardised mean difference (SMD) using a random-effects model with 95% confidence intervals (95% CI). Nineteen studies were included in the systematic review, and 16 in the meta-analysis. IMCL content increased following HFD (SMD=0.63, 95% CI 0.31 to 0.94, p=0.001). IMCL accumulation was not influenced by total fat content (p=0.832) or duration (p=0.844) of HFD, physical activity status (p=0.192) or by the IMCL measurement technique (p>0.05). Insulin sensitivity decreased following HFD (SMD=-0.34, 95% CI -0.52 to -0.16; p=0.003), but this was not related to the increase in IMCL content following HFD (p=0.233). Consumption of a HFD (>35% daily energy intake from fat) for ≥3 days significantly increases IMCL content in healthy individuals regardless of HFD total fat content and duration, or physical activity status. All IMCL measurement techniques detected the increased IMCL content following HFD. The dissociation between changes in IMCL and insulin sensitivity suggests that other factors may drive HFD-induced impairments in insulin sensitivity in healthy individuals. This study was registered with PROSPERO (ref: CRD42021257984).

The age-related decline in appetite and food intake - termed "anorexia of ageing" - is implicated in undernutrition in later life and hence provides a public health challenge for our ageing population. Eating behaviour is controlled, in part, by homeostatic mechanisms which sense nutrient status and provide feedback to appetite control regions of the brain. Such feedback signals, propagated by episodic gut hormones, are dysregulated in some older adults. The secretory responses of appetite-related gut hormones to feeding are amplified, inducing a more anorexigenic signal which is associated with reduced appetite and food intake. Such an augmented response would indicate an increase in gut sensitivity to nutrients. Consequently, this review explores the role of gastrointestinal tract nutrient sensing in age-related appetite dysregulation. We review and synthesise evidence for age-related alterations in nutrient sensing which may explain the observed hormonal dysregulation. Drawing on what is known regarding elements of nutrient sensing pathways in animal models, in other tissues of the body, and in certain models of disease, we identify potential causal mechanisms including alterations in enteroendocrine cell number and distribution, dysregulation of cell signalling pathways, and changes in the gut milieu. From identified gaps in evidence, we highlight interesting and important avenues for future research.

Abstract This study determined the validity, reproducibility and usability of a smartphone app – APPetite – for the measure of free-living, subjective appetite. Validity was assessed compared with the criterion tool of pen-and-paper visual analogue scale (VAS) (n 22). Appetite was recorded using APPetite and VAS, one immediately after the other, upon waking and every hour thereafter for 12 h. This was repeated the next day with the order of tool reversed. Agreement between tools was assessed using Bland–Altman analysis. Reproducibility and usability were assessed in a separate experiment (n 22) of two trials (APPetite v. VAS), separated by 7 d. Appetite was recorded in duplicate upon waking and every hour for 12 h using APPetite or VAS. Agreement between duplicate measures was assessed using Bland–Altman analysis and CV was compared between tools. Usability was assessed by comparing compliance and by qualitative evaluation. APPetite demonstrated good criterion validity with trivial bias of 1·65 units/mm·h–1 between APPetite- and VAS-derived AUC appetite scores. Limits of agreement were within a maximum allowed difference of 10 %. However, proportional bias was observed. APPetite demonstrated high reproducibility, with minimal bias (–0·578 units·h–1) and no difference in CV between APPetite and VAS (1·29 ± 1·42 % v. 1·54 ± 2·36 %, P = 0·64). Compliance was high with APPetite (92·7 ± 8·0 %) and VAS (91·6 ± 20·4 %, P = 0·81). Ninety percent of participants preferred APPetite, citing greater accessibility, simplified process and easier/quicker use. While proportional bias precludes using APPetite and VAS interchangeably, APPetite appears a valid, reproducible and highly usable tool for measuring free-living appetite in young-to-middle-aged adults.

Nutrition strategies and supplements may have a role to play in diminishing exercise associated gastrointestinal cell damage and permeability. The aim of this systematic review was to determine the influence of dietary supplements on markers of exercise-induced gut endothelial cell damage and/or permeability. Five databases were searched through to February 2021. Studies were selected that evaluated indirect markers of gut endothelial cell damage and permeability in response to exercise with and without a specified supplement, including with and without water. Acute and chronic supplementation protocols were included. Twenty-seven studies were included. The studies investigated a wide range of supplements including bovine colostrum, glutamine, probiotics, supplemental carbohydrate and protein, nitrate or nitrate precursors and water across a variety of endurance exercise protocols. The majority of studies using bovine colostrum and glutamine demonstrated a reduction in selected markers of gut cell damage and permeability compared to placebo conditions. Carbohydrate intake before and during exercise and maintaining euhydration may partially mitigate gut damage and permeability but coincide with other performance nutrition strategies. Single strain probiotic strains showed some positive findings, but the results are likely strain, dosage and duration specific. Bovine colostrum, glutamine, carbohydrate supplementation and maintaining euhydration may reduce exercise-associated endothelial damage and improve gut permeability. In spite of a large heterogeneity across the selected studies, appropriate inclusion of different nutrition strategies could mitigate the initial phases of gastrointestinal cell disturbances in athletes associated with exercise. However, research is needed to clarify if this will contribute to improved athlete gastrointestinal and performance outcomes.

Proposed strategies for preventing protein deficiencies in older patients include increasing protein intake at breakfast. However, protein is highly satiating and the effects of very high protein intakes at breakfast on subsequent appetite and free-living energy intake (EI) in older adults are unclear. This study compared the acute effects of two breakfast drinks varying in protein and energy contents on appetite and free-living EI in healthy older adults using a randomized 2 × 2 crossover design. Participants (n = 48 (20 men, 28 women); mean ± SD age: 69 ± 3 years; BMI: 22.2 ± 2.0 kg·m−2; fat-free mass: 45.5 ± 8.0 kg) consumed two drinks for breakfast (high-protein (30.4 ± 5.3 g), low-energy (211.2 ± 37.1 kcal) content (HPLE) and very high-protein (61.8 ± 9.9 g), fed to energy requirements (428.0 ± 68.9 kcal) (VHPER)) one week apart. Appetite perceptions were assessed for 3 h post-drink and free-living EI was measured for the remainder of the day. Appetite was lower in VHPER than HPLE from 30 min onwards (p < 0.01). Free-living energy and protein intake did not differ between conditions (p = 0.814). However, 24 h EI (breakfast drink intake + free-living intake) was greater in VHPER than HPLE (1937 ± 568 kcal vs. 1705 ± 490 kcal; p = 0.001), as was 24 h protein intake (123.0 ± 26.0 g vs. 88.6 ± 20.9 g; p < 0.001). Consuming a very high-protein breakfast drink acutely suppressed appetite more than a low-energy, high-protein drink in older adults, though free-living EI was unaffected. The long-term effects of adopting such a breakfast strategy in older adults at high risk of energy and protein malnutrition warrants exploration.

High-intensity intermittent exercise (HIIE) has been shown to transiently suppress appetite, but such exercise has traditionally required the use of specialist apparatus (e.g., cycle ergometer). This study aimed to determine appetite and eating behaviour responses to acute apparatus-free HIIE in inactive women with excess weight. A preliminary study (n = 18 inactive women, 9 healthy weight, 18.0-24.9 kg∙m-2; 9 with excess weight, 25.0-34.9 kg∙m-2) revealed that intervals of 30 s of "all out" star jumping elicited physiological responses akin to intervals of 30 s of "all out" cycling. Twelve women (29.2 ± 2.9kg∙m-2, 38 ± 7years, 28 ± 39 min MVPA∙week-1) then completed three trials in a within-subject, randomised cross-over design: 4 × 30 s "all out" star jumping (4 × 30 s); 2 × 30 s "all out" star jumping (2 × 30 s); resting control (CONT). Upon completing each late-morning exercise trial, lunch was provided upon request from the participant. The time from the exercise bout to lunch request - termed eating latency - was recorded, and ad libitum food intake at lunch was measured. Subjective appetite was measured using a visual analogue scale before and after exercise, and at lunch request. Free-living energy intake (EI) and energy expenditure (EE) were recorded for the remainder of the trial day and the three days following. Change-from-baseline in subjective appetite was significantly lower immediately after 4 × 30 s (-9.6 ± 18.4 mm) and 2 × 30 s (-11.5 ± 21.2 mm) vs. CONT (+8.1 ± 9.6 mm), (both p < 0.05, d = 0.905 and 1.027, respectively). Eating latency (4 × 30 s: 32 ± 33 min, 2 × 30 s: 31 ± 26 min, CONT: 27 ± 23 min, p = 0.843; η2p = 0.017) and lunch EI (4 × 30 s: 662±178 kcal, 2 × 30 sec: 715 ± 237 kcal, CONT: 726 ± 268 kcal, p = 0.451; η2p = 0.077) did not differ significantly between conditions. No significant differences were observed in trial day EI and EE, or in EI and EE on the three days following exercise (all p > 0.05). Mean trial day relative EI (EI - EE) was 201 ± 370 kcal lower after 4 × 30 s than CONT, but this difference was not statistically significant (p = 0.303, d = 0.585). In conclusion, very low-volume star jumping elicited a transient suppression of appetite without altering eating behaviour. (313 words).

Cross-sectional studies in younger adults have demonstrated a positive association between energy intake (EI) and fat-free mass (FFM), with this relationship seemingly mediated by resting metabolic rate (RMR). Establishing a causal effect longitudinally would be prudent in older adults suffering from loss of appetite. We investigated the effects of FFM on RMR, appetite and EI in 39 healthy older adults (age: 66 ± 4 years, BMI: 25.1 ± 3.5 kg∙m2) assigned to either 12-week resistance training + protein supplementation group (RT + PRO) or control group (CON). Body composition, subjective appetite, leptin, insulin, RMR and laboratory-measured ad libitum EI were measured at baseline, weeks 6 and 12 of the intervention, while daily EI at baseline and week 12. FFM (+1.2 kg; p = 0.002), postprandial subjective appetite (+8 mm; p = 0.027), ad libitum EI (+119 kcal; p = 0.012) and daily EI (+133 kcal; p = 0.010) increased from baseline to week 12 in the RT + PRO. RMR, fasted subjective appetite, leptin and insulin concentrations remained unchanged (all p > 0.05). The increases ad libitum EI correlated with increases in FFM (r = 0.527, p = 0.001), with 54% of the change in EI attributed to FFM changes. In conclusion, FFM increases were associated with an increased ad libitum EI and postprandial appetite in older adults.

APPetite: Validation of a smartphone app-based tool for the remote measure of free-living 1 subjective appetite 2 Adrian Holliday, Kelsie O. Johnson, Mariana Kaiseler & Daniel R. Crabtree 3 4 Human Nutrition Research Centre, Population Health Sciences Institute, Newcastle University, 5 Newcastle upon Tyne, UK 6 Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK 7 Higher Education Sport, Hartpury University, Hartpury, UK 8 Division of Biomedical Sciences, University of the Highlands and Islands, Old Perth Road, Inverness 9 IV2 3JH, Scotland, UK 10 11