The Wisdom of Old Age: Placing the older adult at the heart of healthy eating.

Poor diet and inadequate nutrient consumption are known to be causal in the development of chronic health conditions, many of which increase with age. Older adults also typically have reduced appetite and consequently are often not meeting dietary and nutrient requirements. The causes of reduced appetite are known to be multifactorial but mechanistically are not well understood. Heightened gut hormone responding and poor dentition in older adults have been implicated. Solutions to reduced appetite, including the use of oral nutritional supplements, are often not well received, with older adults preferring to consume "real" foods. Numerous studies have now demonstrated the value of food-based interventions; however some concerns, such as those related to sensory appeal, familiarity and price, can be exacerbated by age. As such, acceptance of solutions by the older generation is paramount in ensuring intervention success, and working with older adults to co-create food-based solutions is more likely to see positive outcomes. The co-creation of foods and dietary advice has been well received across a range of nutrients, including fibre and protein. However, it must also be acknowledged that there are stark individual differences in social gradients and in health between groups of older adults, and this is not always represented in the current literature. Increased awareness of dietary and food requirements in this population group is still needed, and in exploring solutions, much can be gained from consulting with older adults themselves.

Older adults' acceptability of and preferences for food-based protein fortification in the UK, France and Norway.

Research suggests that as we age, protein intake, recognised as vital for combating negative health outcomes, consistently falls below recommendations in older adults. Decreased food intake, combined with age-related eating complications is a major determinant of this protein undernutrition. If nutritional interventions are to be effective and sustainable, they must enable eating pleasure, cater for personal preferences and be adaptable to different eating patterns. As such, we aimed to identify successful strategies for at-home protein-fortification to empower older adults to take a personalised approach to their nutrition, without requiring a large behavioural change. To explore healthy older adults' (age 70+) acceptability and preferences for at-home protein fortification, European project Fortiphy led discussions with older adults (n = 37) and caregivers of older adults (n = 15) to develop high-protein recipes, which were then utilised in a home-use trial with healthy older adults (n = 158). Each fortified recipe was paired with a questionnaire to rate the ease of preparation and liking, and an end-of-study questionnaire was provided to capture overall opinions and preferences. The uniqueness of this study is that the protein fortified recipes were prepared and tested by older adults themselves, in their own homes. Findings showed that older adults were unaware of the importance of protein in ageing and did not have a desire to fortify their foods at present. Yet, they were positive regarding the concept and highlighted the importance of taste, familiar ingredients, and preferred preparation methods. Cultural preferences across countries were identified as having the most influence on the liking of fortified meals. This study also indicated a need for increased awareness of protein requirements to influence the motivation to use fortification.

Macronutrients effects on satiety and food intake in older and younger adults: A randomised controlled trial.

Older adults are advised to increase their protein intake to maintain their muscle mass. However, protein is considered the most satiating macronutrient and this recommendation may cause a decrease in total energy intake. To date, satiety studies comparing all three macronutrients have been undertaken in young adults, and it is unclear if the same response is seen in older adults. The objective of this study was to compare the effect of preloads high in protein, fat, and carbohydrate but equal in energy (∼300 kcal) and volume (250 ml) on energy intake, perceived appetite, and gastric emptying in younger and older adults. Twenty older and 20 younger adults completed a single-blinded randomised crossover trial involving three study visits. Participants consumed a standard breakfast, followed by a preload milkshake high in either carbohydrate, fat, or protein. Three hours after the preload, participants were offered an ad libitum meal to assess food intake. Visual analogue scales were used to measure perceived appetite and gastric emptying was measured via the 13C-octanoic acid breath test. There was no significant effect of preload type or age on energy intake either at the ad libitum meal, self-recorded food intake for the rest of the test day or subjective appetite ratings. There was a significant effect of preload type on gastric emptying latency phase and ascension time, and an effect of age on gastric emptying latency and lag phase such that older adults had faster emptying. In conclusion, energy intake, and perceived appetite were not affected by macronutrient content of the preloads in both younger and older adults, but gastric emptying times differed.

Finger millet-based muffin decreases insulin response in individuals with prediabetes in a randomised controlled trial.

Millet is a grain high in polyphenols and antioxidants, which are bioactive compounds known to influence blood glucose response. The aim of this study was to compare the effect of finger millet muffin and wheat muffin on glycaemic response (GR), insulin response (IR), gastric emptying (GE) and satiety in healthy individuals and people with prediabetes. In a single-blind randomised controlled crossover trial at Oxford Brookes Centre for Nutrition and Health, fifteen healthy individuals and fourteen individuals with prediabetes were recruited between May and December 2017. The participants' GR (3 h), IR (3 h), GE (4 h) and satiety (4 h) were measured before and after the consumption of muffins. A mixed method ANOVA was used to compare GE and the incremental AUC (iAUC) for GR and IR between the participant groups and muffins. There was a significant interaction between participants and muffins on IR iAUC at 180 min (P = 0·042). A significant effect of muffins was found on the GR peak (P = 0·013). The millet muffin decreased the GR peak and IR iAUC compared with the wheat muffin in participants with prediabetes. A significant interaction between participants and muffins for GE ascension time Tasc (P = 0·017) was observed, with no effect of muffins on satiety AUC in the participant groups. This study suggested that polyphenol and fibre-rich finger millet may have the potential to influence the management of prediabetes.

Gluten-free diet intervention reduces thiamine intake in two weeks, increases glycaemic response and decreases body weight in four weeks, with no long term nutritional deficiencies.

This research investigated the effects of gluten free diet (GFD) on nutritional intake, glycaemic and insulin response. In a cross-sectional study, participants who consumed gluten-containing diet (GCD; n = 11) and GFD (n = 11) completed a food diary, blood glucose and insulin measurements. In a pre-post intervention study (n = 11), glycaemic and insulin responses were tested before and after four weeks of a GFD. Food intake was recorded before and after two weeks. No significant differences in nutrient intake, glycaemic or insulin responses were found in the cross-sectional study. In the intervention study, there was a significant reduction in body weight (p = .007) and body mass index (BMI) (p = .004) after four weeks and lower thiamine intake (p = .021) after two weeks of GFD. Glycaemic response was significantly higher (p < .05) following GFD with no differences in insulin response. These differences were not evident if GFD was followed for a longer period, possibly due to improved food choices.

A systematic review and meta-analysis of medium-chain triglycerides effects on acute satiety and food intake.

Research has indicated that consuming medium-chain triglycerides (MCT) may be more satiating than consuming long-chain triglycerides (LCT) potentially causing a reduction in energy intake. However not all studies have demonstrated this acute reduction in energy intake and it has yet to be systematically reviewed. Our main objective was to examine how ingestion of MCT influences energy intake, subjective appetite ratings and appetite-related hormones compared to LCT. Web of Science, MEDLINE, CINHAL, and Embase were searched for publications comparing the effect of MCT on appetite (commonly hunger, fullness, desire to eat, and prospective food consumption), appetite-related hormones (pancreatic polypeptide (PP), gastric inhibitory polypeptide (GIP), peptide YY (PYY), glucagon-like peptide-1 (GLP-1), neurotensin, leptin, total ghrelin and active ghrelin) and energy intake to LCT. A random-effects meta-analysis was conducted on studies which examined energy intake. Seventeen studies (291 participants) were included in the systematic review, of which 11 were included in the energy intake meta-analysis. Synthesis of combined data showed evidence of a statistically significant moderate decrease in ad libitum energy intake after both acute and chronic ingestion of MCT compared to LCT when assessed under laboratory conditions (mean effect size: -0.444, 95% CI -0.808, -0.080, p < 0.017), despite little evidence of any effect of MCT on subjective appetite ratings or circulating hormones. The current evidence supports the notion that MCT decreases subsequent energy intake, but does not appear to affect appetite. Further research is warranted to elucidate the mechanisms by which MCT reduce energy intake.

A comparison of the satiating properties of medium-chain triglycerides and conjugated linoleic acid in participants with healthy weight and overweight or obesity.

PURPOSE: Inconsistent evidence exists for greater satiety after medium-chain triglycerides (MCT) or conjugated linoleic acid (CLA) compared to long-chain triglycerides (LCT). Furthermore, the mechanisms are poorly understood and effects in people with a healthy weight and those with overweight/obesity have not been compared. This study aimed to compare appetite responses in these groups and examine the mechanisms behind any differences. METHODS: Fifteen participants with healthy weight (BMI: 22.7 ± 1.9 kg·m-2) and fourteen participants with overweight/obesity (BMI: 30.9 ± 3.9 kg·m-2) consumed a breakfast containing either 23.06 g vegetable oil (CON), 25.00 g MCT oil (MCT), or 6.25 g CLA and 16.80 g vegetable oil (CLA). Appetite, peptide YY (PYY), total ghrelin (TG), ß-hydroxybutyrate, and gastric emptying (GE) were measured throughout. Energy intake was assessed at an ad libitum lunch and throughout the following ~ 36 h. RESULTS: Neither MCT nor CLA decreased ad libitum intake; however MCT decreased day 1 energy intake (P = 0.031) and the 48-h period (P = 0.005) compared to CON. MCT delayed GE (P ≤ 0.01) compared to CON, whereas CLA did not. PYY and TG concentrations were not different (P = 0.743 and P = 0.188, respectively), but MCT increased ß-hydroxybutyrate concentrations compared to CON (P = 0.005) and CLA (P < 0.001). ß-hydroxybutyrate concentrations were higher in participants with overweight/obesity (P = 0.009). CONCLUSION: Consumption of MCT reduces energy intake in the subsequent 48 h, whereas CLA does not. Delayed gastric emptying or increased ß-hydroxybutyrate concentrations may mediate this.

The effect of a split portion of flaxseed on 24-h blood glucose response.

PURPOSE: Flaxseed can be effective at lowering and stabilising blood glucose responses. The aim of this study was to determine whether flaxseed could lower blood glucose response more effectively when consumed as a single portion of 30 g, or a split portion consumed three times per day (10 g flaxseed per portion). METHODS: The study was a randomised, repeated measures, cross-over design. Fifteen healthy participants consumed either (1) three flaxseed muffins containing a total of 30 g of flaxseed once in the morning, (2) three flaxseed muffins consumed at three different timepoints across the day (10 g flaxseed per muffin) or (3) three control muffins consumed at three different timepoints across the day (0 g flaxseed). The 24-h blood glucose response was measured using a continuous glucose monitor. RESULTS: The results of this study demonstrated that flaxseed muffins given three times a day were effective at lowering and maintaining blood glucose levels over 24 h, compared to the control muffins and that both flaxseed treatments resulting in a lower blood glucose iAUC during the night. CONCLUSION: The results of this study indicated that adding flaxseed to a daily diet produced a lower glucose profile over 24 h in a free-living context compared to the control muffins.

Dietary lipids with potential to affect satiety: Mechanisms and evidence.

Dietary fat has been implicated in the rise of obesity due to its energy density, palatability and weak effects on satiety. As fat is a major contributor to overall energy intake, incorporating fat with satiating properties could potentially reduce energy intake. This review outlines the potential mechanisms, as far as we know, by which Medium-Chain Triglycerides (MCT), Conjugated Linoleic Acid (CLA), Short-Chain Fatty Acids (SCFA), Diacylglycerol (DAG), n-3 PUFA, and Small Particle Lipids, exerts their satiating effects. The evidence suggests that the lipid with the most potential to enhance satiety is MCT. SCFA can also promote satiety, but oral administration has been linked to poor tolerability rather than satiety. Data on the appetite effects of CLA is limited but does suggest potential. Research comparing these lipids to each other is also lacking and should be explored to elucidate which of these 'functional lipids' is the most beneficial in enhancing satiety.

Effect of medium-chain TAG and exercise on satiety, energy intake and energy balance.

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.

Standard v. baby-led complementary feeding: a comparison of food and nutrient intakes in 6-12-month-old infants in the UK.

OBJECTIVE: To compare food and nutrient intakes of infants aged 6-12 months following a baby-led complementary feeding (BLCF) approach and a standard weaning (SW) approach. DESIGN: Participants completed an online questionnaire consisting of sociodemographic questions, a 28 d FFQ and a 24 h dietary recall. SETTING: UK. PARTICIPANTS: Infants (n 134) aged 6-12 months (n 88, BLCF; n 46, SW). RESULTS: There was no difference between weaning methods for the food groups 'fruits', 'vegetables', 'all fish', 'meat and fish', 'sugary' or 'starchy' foods. The SW group was offered 'fortified infant cereals' (P < 0·001), 'salty snacks' at 6-8 months (P = 0·03), 'dairy and dairy-based desserts' at 9-12 months (P = 0·04) and 'pre-prepared baby foods' at all ages (P < 0·001) more often than the BLCF group. The SW group was offered 'oily fish' at all ages (P < 0·001) and 6-8 months (P = 0·01) and 'processed meats' at all ages (P < 0·001), 6-8 months (P = 0·003) and 9-12 months (P < 0·001) less often than the BLCF group. The BLCF group had significantly greater intakes of Na (P = 0·028) and fat from food (P = 0·035), and significantly lower intakes of Fe from milk (P = 0·012) and free sugar in the 6-8 months subgroup (P = 0·03) v. the SW group. Fe intake was below the Reference Nutrient Intake (RNI) for both groups and Na was above the RNI in the BLCF group. CONCLUSION: Compared with the SW group, the BLCF group was offered foods higher in Na and lower in Fe; however, the foods offered contained less free sugar.

The Effect of Mode of Transport on Intraindividual Variability in Glycemic and Insulinemic Response Testing.

The effect of light- to moderate-intensity exercise, such as that used as a mode of transport, on glycemic response testing is unclear. The aim was to investigate the effect of acute exercise (walking and cycling), simulated to act as a mode of transport, prior to glycemic response testing on the intraindividual variability of blood glucose and insulin. A total of 11 male participants visited the laboratory four times. Initially, they undertook a maximum oxygen uptake and two submaximal exercise tests. For the other three visits, they either rested (25 min), cycled, or walked 5 km followed by a 2-hr glycemic response test after consuming a glucose drink (50 g of available carbohydrate). The mean coefficient of variation of each transport group was below the International Organization for Standardization cutoff of 30%. The highest mean coefficient of variation of glucose area under the curve (AUC) was between the rest and the walking trials (30%) followed by walking and cycling (26%). For insulin AUC, the highest mean coefficient of variation was between walking and cycling (28%) followed by rest and walking (24%). The lowest glucose AUC and insulin AUC were between rest and cycling (25% and 14%, respectively). This study did not find differences (p > .05) between the conditions for glucose AUC (at 120 min, rest: 134.5 ± 104.6 mmol/L; walking: 115.5 ± 71.7 mmol/L; and cycling: 142.5 ± 75 mmol/L) and insulin AUC (at 120 min, rest: 19.45 ± 9.12 µmol/ml; walking: 16.49 ± 8.42 µmol/ml; and cycling: 18.55 ± 9.23 µmol/ml). The results indicate no difference between the tests undertaken; however, further research should ensure the inclusion of two rest conditions.

The effect of agar jelly on energy expenditure, appetite, gastric emptying and glycaemic response.

BACKGROUND AND PURPOSE: Agar contains a high amount of soluble fibre and has been shown to delay gastric emptying (GE) without impacting on glycaemic response (GR). The current study aimed to further the limited data on the effect of agar on metabolism by assessing the effects on GE and GR as well as appetite- and diet-induced thermogenesis (DIT). METHODS: In this randomized control trial, eleven healthy volunteers were tested on two occasions following an overnight fast. Following baseline and resting measurements, volunteers were either fed a fruit-flavoured drink (liquid) or consumed a fruit-flavoured jelly (jelly). The two were exactly the same in composition except the jelly contained 4 g of agar crystals. Both contained 50 g of available carbohydrate. DIT was measured using indirect calorimetry, GE using the (13)C sodium acetate breath test, appetite using visual analogue scale and GR using finger prick blood samples. RESULTS: The jelly significantly delayed GE across all time points-latency phase (p = 0.07), lag phase (p = 0.04), half-time (p < 0.0001), ascension time (p = 0.025). The jelly also increased all appetite parameters-hunger (p = 0.006), fullness (p = 0.035), desire to eat (p = 0.03) and prospective consumption (p = 0.011). However, there were no significant differences in either GR or postprandial DIT between the liquid and jelly. CONCLUSION: Agar delays GE and increases appetite but does not change GR or DIT most probably due to the increase in viscosity caused by the agar jelly.

Molecular weight of barley ß-glucan does not influence satiety or energy intake in healthy male subjects.

Previous studies have shown the ability of high molecular weight barley ß-glucan with increased viscosity to attenuate glycemic response, gastric emptying and in vitro starch digestion. The main objective of this study was to investigate the effect of molecular weight of barley ß-glucan in a semisolid meal on energy intake and subjective feelings of hunger, fullness, desire to eat and prospective food consumption in healthy male subjects. In a randomised, controlled, crossover trial, 23 healthy male subjects (BMI 24.2 ± 2.5 kg/m²) tested soups equivalent to 25 g available carbohydrate containing high or low molecular weight barley ß-glucan (~3 g) as preload after a standard breakfast. The viscosity of soup with high molecular weight ß-glucan was 350 Pa·s whereas the soup with low molecular weight ß-glucan had a viscosity of 100 Pa·s. Appetite ratings before and for two hours after consumption of ß-glucan soups and subsequent ad libitum energy intake at lunch were recorded and compared with a control soup with no ß-glucan. There was no significant difference in food intake at the ad libitum meal or for the remainder of the day following consumption of the three test foods (p > 0.05). Similarly, there were no significant differences (p > 0.05) in hunger, fullness, desire to eat or prospective food consumption following ß-glucan soups. The current study provides evidence that the molecular weight of barley ß-glucan may not impact on perceived feelings of hunger or food intake at the current dose and viscosity.

Understanding age-related changes: exploring the interplay of protein intake, physical activity and appetite in the ageing population.

Globally, we are currently facing a rapid demographic shift leading to an increase in the proportion of older adults within the population. This raises concerns about the potential increase in age-related diseases and their impact on our ability to provide adequate health and end-of-life care. To apply appropriate interventions, understanding the changes that happen with ageing becomes essential. Ageing is often accompanied by a decrease in appetite and physical activity, which may lead to malnutrition, resulting in decreased muscle mass, physical capabilities and independence. To preserve muscle mass, older adults are advised to increase protein intake and physical activity. However, protein's high satiating effect may cause reduced energy intake. Physical activity is also advised to maintain or enhance older adult's appetite. This review paper aims to discuss appetite-related changes that occur with ageing and their consequences. In particular, it will focus on investigating the relationship between protein intake and physical activity and their impact on appetite and energy intake in the ageing population. Recent studies suggest that physical activity might contribute to maintaining or enhancing appetite in older adults. Nevertheless, establishing a definitive consensus on the satiating effect of protein in ageing remains a work in progress, despite some promising results in the existing literature.

Combined medium-chain triglyceride and chilli feeding increases diet-induced thermogenesis in normal-weight humans.

BACKGROUND AND PURPOSE: Capsaicin, the active ingredient of chilli, and medium-chain triglycerides (MCT) have been shown to increase diet-induced thermogenesis (DIT), improve satiety and decrease energy intake. Combinations of thermogenic ingredients have previously been investigated such as mustard and chilli, or capsaicin and green tea with positive effects. The aim of this study was to investigate the combined effects of chilli and MCT feeding on DIT and satiety in healthy volunteers. METHODS: Seven healthy volunteers were tested on four occasions following an overnight fast. Volunteers were fed a breakfast containing chilli and MCT oil, chilli and sunflower oil, bell pepper and sunflower oil or bell pepper and MCT oil. Satiety and gastrointestinal comfort were measured using visual analogue scales (VAS) and category scales. Baseline energy expenditure, and DIT and fat oxidation were measured for 6 h using indirect calorimetry. RESULTS: There were significant differences in DIT between the meals (P = 0.003) which increased from 7.0 % for pepper-sunflower oil to 10.7 % for chilli-MCT oil. The predominant differences existed between the chilli-MCT oil and chilli-sunflower oil (P = 0.013), between chilli-MCT oil and pepper-sunflower oil (P = 0.007) and between pepper-sunflower oil and pepper-MCT oil (P = 0.004). There was a significant difference in fat oxidation between the pepper-sunflower oil and pepper-MCT oil (P = 0.032). There were no differences in any VAS satiety parameters or gastrointestinal comfort ratings. CONCLUSION: Adding chilli and MCT to meals increases DIT by over 50 % which over time may cumulate to help induce weight loss and prevent weight gain or regain.

The Food4Years Ageing Network: Improving foods and diets as a strategy for supporting quality of life, independence and healthspan in older adults.

By 2050, it is predicted that one in four people in the United Kingdom will be aged 65 years and over. Increases in lifespan are not always translated into years spent in good health. Incidence rates for chronic diseases are increasing, with treatments allowing people to live longer with their disease. There is good evidence to support changes to lifestyle to maintain or improve body composition, cognitive health, musculoskeletal health, immune function and vascular health in older adults. Much research has been done in this area, which has produced significant support for foods and nutrients that contribute to improved healthspan. Yet two major barriers remain: firstly, older adult consumers are not meeting current UK recommendations for macro- and micronutrients that could benefit health and quality of life and secondly, the UK-specific recommendations may not be sufficient to support the ageing population, particularly for nutrients with key physiological roles. More work is needed to improve intakes of specific foods, diets and nutrients by older adults, through a variety of mechanisms including (i) development of specific food products; (ii) improved clarity of information and (iii) appropriate marketing, and policy changes to enable incentives. The Food4Years Ageing Network aims to build a wide-reaching and multidisciplinary community that is committed to the development, integration and communication of healthy, affordable foods and specific diets for all older adults across the UK food landscape. The Network will identify evidence-based strategies for improving food intake and nutrition in older adults, paving the way to "living well while living longer."

'Raising the Pulse': The environmental, nutritional and health benefits of pulse-enhanced foods.

Diet is a key modulator of non-communicable diseases, and food production represents a major cause of environmental degradation and greenhouse gas emissions. Yet, 'nudging' people to make better food choices is challenging, as factors including affordability, convenience and taste often take priority over the achievement of health and environmental benefits. The overall 'Raising the Pulse' project aim is to bring about a step change in the nutritional value of the UK consumers' diet, and to do so in a way that leads to improved health and greater sustainability within the UK food system. To achieve our objectives, UK-specific faba bean production systems that optimise both end users' diets and environmental and economic sustainability of production will be implemented in collaboration with key stakeholders (including industry, the retail sector and government). Palatable faba bean flours will be produced and used to develop 'Raising the Pulse' food products with improved nutritional profile and environmental value. Consumer focus groups and workshops will establish attitudes, preferences, drivers of and barriers to increased consumption of such products. They will inform the co-creation of sensory testing and University-wide intervention studies to evaluate the effects of pulses and 'Raising the Pulse' foods on diet quality, self-reported satiety, nutritional knowledge, consumer acceptance and market potential. Nutrient bioavailability and satiety will be evaluated in a randomised-controlled postprandial human study. Finally, a system model will be developed that predicts changes to land use, environment, business viability, nutrition and human health after substitution of existing less nutritionally beneficial and environmentally sustainable ingredients with pulses. Government health and sustainability priorities will be addressed, helping to define policy-relevant solutions with significant beneficial supply chain economic impacts and transformed sustainable food systems to improve consumer diet quality, health and the environment.

The addition of raspberries and blueberries to a starch-based food does not alter the glycaemic response.

It is now known that health benefits associated with diets rich in fruit and vegetables may be partly derived from intake of polyphenols. Berry polyphenols may influence carbohydrate metabolism and absorption and hence postprandial glycaemia. To date, studies related to polyphenol effects on the glycaemic response have been completed only in liquids using either monosaccharides or disaccharides. It remains to be determined whether berries known to be rich in polyphenols can reduce the glycaemic response (GR) to a solid polysaccharide meal. The aim of the present study was to investigate whether berries alter postprandial hyperglycaemia and consequently the GR to a starchy food. Blood glucose was tested on seven occasions, on three occasions using a reference food and on four occasions using pancakes supplemented with either raspberries or blueberries or control pancakes containing similar amounts of fructose and glucose. Results showed that there were no differences in GR (blueberry 51·3 (SEM 5·7); raspberry 54·7 (SEM 5·6); blueberry control 43·9 (SEM 4·2); raspberry control 41·8 (SEM 6·4)), GR area under the curve or satiety index between any of the tests. The present study indicates that the ability of berries to reduce blood glucose from starch-based foods is unsubstantiated.

A high-fat diet temporarily accelerates gastrointestinal transit and reduces satiety in men.

High-fat (HF) diets of 2 weeks have been shown to accelerate gastrointestinal (GI) transit and decrease satiety. However, the effects of HF diets on GI transit over longer periods than 2 weeks are unknown. We hypothesize that over 4 weeks, GI transit of a HF test meal will accelerate. The study was a repeated measures design with 10 male volunteers completing a 1-week HF diet intervention and 7 completing a 4-week HF diet intervention with testing once a week on the same day throughout the 4 weeks. Gastric emptying (GE) was measured using the (13)C-octanoic acid breath test and mouth-to-caecum transit time (MCTT) using the inulin H(2) breath test. Satiety was analysed using visual analogue scales and an ad libitum buffet meal. Body mass increased by 1.3 kg over the 4 weeks (p = 0.036). GE latency time decreased from 45 ± 8 to 41 ± 10 min (p = 0.047) over 1 week but there were no changes in any GE parameters over the 4 weeks. MCTT was accelerated over 1 week (p = 0.036) from 308 ± 43 to 248 ± 83 min. However, over the 4-week period, there was no change. Volunteers became more hungry and desire to eat became greater after 1 week (p = 0.01). Changes in satiety were also evident over the 4 weeks. Satiety was reduced in the primary weeks and then returned to baseline towards the end of the intervention. GI adaptation to a HF diet occurred over a 1-week period and returned to pre-diet levels at the end of 4 weeks.