The Difference between PC-Based and Immersive Virtual Reality Food Purchase Environments on Useability, Presence, and Physiological Responses.

Computer simulations used to study food purchasing behavior can be separated into low immersion virtual environments (LIVE), which use personal computers and standard monitors to display a scene, and high immersion virtual environments (HIVE) which use virtual reality technology such as head-mounted displays to display a scene. These methods may differ in their ability to create feelings of presence or cybersickness that would influence the usefulness of these approaches. In this present study, thirty-one adults experienced a virtual supermarket or fast-food restaurant using a LIVE system or a HIVE system. Feelings of presence and cybersickness were measured using questionnaires or physiological responses (heart rate and electrodermal activity). The participants were also asked to rate their ability to complete the set task. The results of this study indicate that participants reported a higher sense of presence in the HIVE scenes as compared to the LIVE scenes (p < 0.05). The participant's heart rate and electrodermal activity were significantly higher in the HIVE scene treatment when compared to the LIVE scene (p < 0.05). There was no difference in the participant's ability to complete tasks in the different scenes. In addition, feelings of cybersickness were not different between the HIVE and LIVE scenes.

Virtual Reality and Powerpoint Grocery Store Tours: Equally Effective in Improving Self-efficacy in Randomised Control Trial.

PURPOSE: Compare computer-based virtual reality (CBVR) and voice-over PowerPoint (PP) grocery store tours (GST) on adult nutrition literacy (NL) and healthful food purchasing self-efficacy (HFPSE). DESIGN: Participants (n = 68) recruited from University worksite wellness program and randomly assigned to CBVR or PP (CBVR = 35; PP = 33). INTERVENTION: Four-week culinary/nutrition education program. Initial three weeks provided identical education for both groups. Week four implemented GST intervention using CBVR or PP. MEASURES: NL and HFPSE surveys before, after, and three-months post from the start of program. ANALYSIS: Intent-to-treat (ITT) analysis with RMANOVA (95% confidence intervals [CI] and effect sizes) to examine change in NL and HFPSE between CBVR and PP groups over 4-week intervention and 3-month retention period. RESULTS: 43 of 68 participants [CBVR (n = 19) and PP (n = 24)] were included in analyses. Both groups significantly improved HFPSE over time (P<.001, CBVR = 46.23% PP = 33.34%), but there were no differences between groups (P = .21) or group by time interaction (P = .31). NL did not change for either group (P = .83, CBVR = 1.11%; PP = .12%) nor were there differences between groups (P = .07). CONCLUSIONS: CBVR and PP GST significantly improved and maintained higher HFPSE scores.

Virtual Reality as a Tool to Study the Influence of the Eating Environment on Eating Behavior: A Feasibility Study.

In this manuscript, we describe a new approach to study the effect of the eating environment on food intake and eating behavior using virtual reality technology. Fifteen adults consumed pizza rolls in two virtual reality (VR) environments: a restaurant and a table in an empty room. The participants' food intake, eating parameters (e.g., masticatory parameters and eating rate), and their sensory evaluation of the test food was measured. The participants' sense of presence (the feeling of being in the virtual environment) and markers of arousal were also measured. There was no statistical significant difference in food intake or the sensory evaluation of the test food. In the restaurant condition, participants used fewer masticatory cycles before swallowing but there was no effect on eating rate or maximum bite force. Participants experienced a greater sense of presence when they were in the pizza restaurant scene. Moreover, their heart rate and skin temperature were higher in the restaurant condition. This study suggests that VR could be developed as a new tool to study the effect of the eating environment on food intake and eating behavior.

The Effect of Soluble Fiber Dextrin on Subjective and Physiological Markers of Appetite: A Randomized Trial.

Obesity is a leading public health problem throughout the world. The development of foods that increase satiety and reduce food may aid weight management. This study determined the effect of consuming soluble fiber dextrin (SFD) on appetite, appetitive hormones, breath hydrogen and food intake in adults. Forty-three participants completed this study. For each treatment, 50% of the SFD was provided in liquid form as part of breakfast and 50% in solid form as a morning snack. Appetite questionnaires, blood and breath samples were collected immediately before breakfast and at regular intervals during the test session. The participants consumed an ad libitum lunch meal, afternoon snack and dinner meal, and the amount eaten was recorded. Following dinner, participants left the laboratory but were required to keep a diet diary for the remainder of the day. Breath hydrogen concentration was significantly higher following the consumption of SFD compared to control (p < 0.05). There was no observed overall treatment effect of consuming SFD on GLP-1 (Glucagon-Like-Peptide-1), ghrelin, CCK-8 (Cholecystokinin) or PYY3-36 (Petptide YY) (p > 0.05). Moreover, consuming foods containing SFD had no effect on subjective appetite or food intake (p > 0.05). Consuming foods containing SFD increased breath hydrogen but did not influence food intake, appetite or appetitive hormones. However, the limitations of this study may have individually or collectively masked an effect of SFD on food intake and appetite.

Session 3 Discussion: The microstructure of eating.

The Microstructure of Eating.

The effect of mastication on food intake, satiety and body weight.

As mastication is the major component of the oral processing of solid foods a better understanding of its influence on ingestion, digestion and metabolism may lead to new approaches to improve health. A growing number of studies provide evidence that mastication may influence energy balance through several routes: activation of histaminergic neurons, reducing eating rate, altered digestion kinetics, and changes in macronutrient availability. Indeed, accumulating evidence indicates that increasing the number of masticatory cycles before swallowing reduces food intake and increases satiety. However, while slowing eating rate has been shown to limit weight gain in children and adolescents it is not clear that slowing eating rate by increasing the number of masticatory cycles or slowing mastication rate is a viable method to aid weight management ([10], [15]). Further research is required to determine the influence of mastication on energy balance and how it could be manipulated to aid weight management. This narrative review will provide a brief overview of the effect of mastication on food intake, satiety and body weight.

The effect of soluble fiber dextrin on postprandial appetite and subsequent food intake in healthy adults.

OBJECTIVES: This crossover study investigated the effect of consuming a beverage that contains soluble fiber dextrin (SFD) on appetite and food intake in adults to test the hypothesis that beverages that contain 10 or 20 g of fiber from SFD would be more satiating than the control beverage. METHODS: Forty-one participants consumed lunch with a beverage that contained 0 g, 10 g, or 20 g of fiber from SFD. Appetite questionnaires were completed and blood samples collected immediately before lunch and at regular intervals over the following 150 min. Then, participants were provided with an afternoon snack and the amount eaten was recorded. Participants then left the laboratory but were asked to complete hourly appetite questionnaires and record food intake for the remainder of the day. RESULTS: Consuming SFD had no effect on appetite over the 150 min after consumption of the lunch meal (P > 0.05). Hunger and desire to eat were lower and fullness higher after consumption of the beverage that contained 20 g of fiber from SFD (P < 0.05) after participants left the laboratory. There was no effect of consuming SFD on food intake at the snack meal or for the rest of the day (P > 0.05). Plasma glucose-dependent insulintropic polypeptide was lower during the 150 min after consumption of 20 g fiber from the SFD beverage (P < 0.05). There was no treatment effect on the plasma concentration of other biomarkers of glycemic response or appetite (P > 0.05). CONCLUSIONS: Overall, the study results did not show an effect of SFD on appetite, food intake, and plasma markers of appetite for the first 150 min postconsumption. Further research is required to quantify how SFD influences appetite several hours after consumption.

Effect of resistant wheat starch on subjective appetite and food intake in healthy adults.

OBJECTIVE: The aim of this study was to determine the effect of replacing standard wheat flour (SWF) with resistant wheat starch (RWS) on markers of appetite and food intake in healthy adults. METHODS: A randomized, single-blind, crossover study was conducted with 27 healthy adults (ages 23 ± 2 y with a body mass index of 23.0 ± 3.0 kg/m2). After an overnight fast, muffins that contained only SWF or muffins in which 40% of the SWF was replaced with RWS were consumed as part of the breakfast meal. Appetite questionnaires and plasma samples were collected before the test meal and at 10 time points after meal consumption. An ad libitum meal was provided 240 min after breakfast, and the amount eaten was recorded. Food intake was recorded over the remainder of the day using a diet diary, and appetite was measured hourly using appetite questionnaires. Plasma was assayed to measure biomarkers of satiety and glycemia. RESULTS: Replacing SWF with RWS had no effect on subjective appetite or energy intake at the lunch meal (P > 0.05). Total daily energy intake (including the breakfast meal) was reduced by 179 kcal when participants consumed the RWS muffins (P = 0.05). Replacing SWF with RWS reduced plasma insulin (P < 0.05) but had no effect on plasma glucose, cholecystokinin, glucagon-like peptide-1, or peptide YY3-36 concentration (P > 0.05). CONCLUSIONS: These results indicate that replacing SWF with RWS decreases plasma insulin concentration and reduces energy intake over a 24-h period.

A brief review of salient factors influencing adult eating behaviour.

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.

The effect of the macronutrient composition of breakfast on satiety and cognitive function in undergraduate students.

PURPOSE: It is believed that breakfast is an important meal due to its effect on appetite control and cognitive performance, yet little evidence exists to support this hypothesis. METHODS: Using a crossover design, 33 healthy undergraduates (aged 22 ± 2 years with a BMI of 23.5 ± 1.7 kg/m2) were randomized one of four breakfast treatments: no breakfast, a low-protein breakfast containing no animal protein, a high-carbohydrate/low-protein breakfast containing animal protein or a low-carbohydrate/high-protein breakfast. After an overnight fast, participants reported to the laboratory and baseline appetite questionnaires and cognitive tests were completed. A baseline blood sample was also collected. These measures were repeated at regular intervals throughout the test session. An ad libitum lunch meal was provided 240 min after breakfast, and the amount eaten recorded. Diet diaries and hourly appetite questionnaires were completed for the rest of the day. RESULTS: The no-breakfast treatment had a marked effect on appetite before lunch (p < .05). Moreover, participants consumed more energy at lunch following the no-breakfast treatment (p < .05). There was no difference in appetite before lunch or food intake at lunch following any treatment when breakfast was eaten. However, food intake over the entire test day was lowest for the no-breakfast treatment (p < .05). Plasma glucose and insulin were lower following the high-protein/low-carbohydrate treatment compared to the low-protein/high-carbohydrate-no animal protein treatment (p < .05). Participants were less happy when they missed breakfast (p < .05), but there were no other statistically significant effects of breakfast on mood or cognitive performance. CONCLUSIONS: These results suggest that changing the macronutrient content of breakfast influences the glycemic response, but has no effect on the appetitive or cognitive performance measures used in this present study.

Postprandial serum endotoxin in healthy humans is modulated by dietary fat in a randomized, controlled, cross-over study.

BACKGROUND: High-fat diets may contribute to metabolic disease via postprandial changes in serum endotoxin and inflammation. It is unclear how dietary fat composition may alter these parameters. We hypothesized that a meal rich in n-3 (ω3) fatty acids would reduce endotoxemia and associated inflammation but a saturated or n-6 (ω6) fatty acid-rich meal would increase postprandial serum endotoxin concentrations and systemic inflammation in healthy adults. METHODS: Healthy adults (n = 20; mean age 25 ± 3.2 S.D. years) were enrolled in this single-blind, randomized, cross-over study. Participants were randomized to treatment and reported to the laboratory, after an overnight fast, on four occasions separated by at least one week. Participants were blinded to treatment meal and consumed one of four isoenergetic meals that provided: 1) 20 % fat (control; olive oil) or 35 % fat provided from 2) n-3 (ω3) (DHA = 500 mg; fish oil); 3) n-6 (ω6) (7.4 g; grapeseed oil) or 4) saturated fat (16 g; coconut oil). Baseline and postprandial blood samples were collected. Primary outcome was defined as the effect of treatment meal on postprandial endotoxemia. Serum was analyzed for metabolites, inflammatory markers, and endotoxin. Data from all 20 participants were analyzed using repeated-measures ANCOVA. RESULTS: Participant serum endotoxin concentration was increased during the postprandial period after the consumption of the saturated fat meal but decreased after the n-3 meal (p < 0.05). The n-6 meal did not effect a different outcome in participant postprandial serum endotoxin concentration from that of the control meal (p > 0.05). There was no treatment meal effect on participant postprandial serum biomarkers of inflammation. Postprandial serum triacylglycerols were significantly elevated following the n-6 meal compared to the n-3 meal. Non-esterified fatty acids were significantly increased after consumption of the saturated fat meal compared to other treatment meals. CONCLUSIONS: Meal fatty acid composition modulates postprandial serum endotoxin concentration in healthy adults. However, postprandial endotoxin was not associated with systemic inflammation in vivo. TRIAL REGISTRATION: This study was retrospectively registered at clinicaltrials.gov as NCT02521779 on July 28, 2015.

Associations between eating frequency and energy intake, energy density, diet quality and body weight status in adults from the USA.

To investigate associations between eating frequency and energy intake, energy density, diet quality and body weight status in adults from the USA, combined data from the 2009-2010 and 2011-2012 National Health and Nutrition Examination Survey (NHANES) were used in this study. The first 24-h dietary recall data from eligible participants (4017 men and 3774 women) were used to calculate eating frequency, as well as energy intake, energy density and the Healthy Eating Index 2010 (HEI-2010), as a measure of diet quality. BMI and waist circumference were obtained from the NHANES body measures data. Adjusting for confounding socio-demographic characteristics and lifestyle factors, a higher eating frequency was significantly associated with higher energy intake in both men and women (both P<0·001). A higher eating frequency was also significantly associated with lower energy density in both men and women, regardless of whether beverage or water intake was included in the calculation of energy density (all P<0·01). Moreover, there was a significant positive association between eating frequency and the HEI-2010 total score in both men and women (both P<0·001). Eating frequency was inversely associated with BMI in women (P=0·003), as well as waist circumference in both men (P=0·032) and women (P=0·010). Results from the present study suggested that adults with a higher eating frequency in the USA had a healthier diet with lower energy density and better diet quality, and eating frequency was inversely associated with body weight status.

Differences in chewing behaviors between healthy fully dentate young and older adults assessed by electromyographic recordings.

To characterize changes in chewing behaviors associated with healthy aging, 10 young and 10 older fully dentate healthy participants were enrolled in this study. They chewed carrot samples that differed in hardness until their normal swallowing threshold. Their chewing behaviors were assessed using an electromyographic recording device. Adjusting for gender and body mass index, older adults had a higher number of chewing cycles (p = 0.020), a longer chewing duration (p < 0.001), a slower chewing rate (p = 0.002), a greater maximal electromyographic voltage (p = 0.003) and a greater muscle activity (p = 0.002) before they could comfortably swallow the food bolus. A statistically significant main effect of food hardness on the number of chewing cycles, chewing duration, chewing rate and muscle activity was also observed (p < 0.001 for all). These results suggest that reduced mastication efficiency is associated with healthy aging in fully dentate adults. This ingestive behavior may contribute to aging-related reduction in appetite in older adults.

Associations between the number of natural teeth and metabolic syndrome in adults.

AIM: To explore associations between the number of natural teeth and metabolic syndrome in adults. MATERIAL AND METHODS: Cross-sectional data from the National Health and Nutrition Examination Survey 2005-2008 were used. Eligible adults (n = 5511) were classified into four groups by their number of natural teeth (excluding third molars): full dentition, 21-27 teeth, 1-20 teeth, or edentulous. Metabolic syndrome was defined by diagnostic guidelines from the American Heart Association and National Heart, Lung, and Blood Institute. Associations were analysed by survey logistic regression. Biometric and metabolic parameters in different dentition groups were compared. RESULTS: Adjusting for age, gender, race/ethnicity, ratio of family income to poverty, physical activity, smoking, and energy intake, tooth loss was significantly associated with metabolic syndrome (p = 0.002). Compared to participants with full dentition, the odds were 32% higher in those with 21-27 teeth, 55% higher in those with 1-20 teeth and 79% higher in edentulous participants. The number of natural teeth was inversely associated with body mass index, waist circumference, blood pressure, fasting plasma glucose and insulin concentrations (p < 0.01 for all); it was positively associated with serum HDL cholesterol concentration (p = 0.003). CONCLUSIONS: The number of natural teeth is inversely associated with the presence of metabolic syndrome in adults.

Relationship between chewing behavior and body weight status in fully dentate healthy adults.

Recent research indicates that chewing behavior may influence energy intake and energy expenditure. However, little is known about the relationship between chewing behavior and body weight status. In the present study, 64 fully dentate normal-weight or overweight/obese adults were asked to consume five portions of a test food and the number of chewing cycles, chewing duration before swallowing and chewing rate were measured. Adjusting for age and gender, normal-weight participants used a higher number of chewing cycles (p = 0.003) and a longer chewing duration (p < 0.001) to consume each portion of the food, compared to overweight/obese participants. However, there was no significant difference in their chewing rate (p = 0.597). A statistically significant negative correlation between body mass index and the number of chewing cycles (r = -0.296, p = 0.020) and chewing duration (r = -0.354, p = 0.005) was observed. In conclusion, these results suggest that chewing behavior is associated with body weight status in fully dentate healthy adults.

The associations between yogurt consumption, diet quality, and metabolic profiles in children in the USA.

PURPOSE: Recent studies have shown that yogurt consumption was associated with better diet quality and a healthier metabolic profile in adults. However, such associations have not been investigated in children. The present study examined the associations in children using data from a nationally representative survey. METHODS: Data from 5,124 children aged 2-18 years, who participated in the National Health and Nutrition Examination Survey (NHANES) between 2003 and 2006 in the USA were analyzed. The frequency of yogurt consumption over 12 months was determined using a validated food frequency questionnaire. Diet quality was assessed by the Healthy Eating Index 2005 (HEI-2005) using one 24-HR dietary recall, and metabolic profiles were obtained from the NHANES laboratory data. RESULTS: It was found that only 33.1 % of children consumed yogurt at least once per week (frequent consumers). Adjusting for covariates, frequent consumers had better diet quality than infrequent consumers, as indicated by a higher HEI-2005 total score (P = 0.04). Frequent yogurt consumption was associated with a lower fasting insulin level (P < 0.001), a lower homeostatic model assessment of insulin resistance (P < 0.001), and a higher quantitative insulin sensitivity check index (P = 0.03). However, yogurt consumption was not associated with body weight, fasting glucose, serum lipid profiles, C-reactive protein, and blood pressures (all P > 0.05). CONCLUSIONS: These results suggest that frequent yogurt consumption may contribute to improved diet quality and a healthier insulin profile in children. Future longitudinal studies and clinical trials in children are warranted to explore the health benefits of yogurt consumption.

Tooth loss and its association with dietary intake and diet quality in American adults.

OBJECTIVES: To investigate associations between the number of natural teeth and energy intake, nutrient intake, and diet quality in adults. METHODS: Eligible adults who participated in the National Health and Nutrition Examination Survey during 2005-2008 were included in the present study (n=9140). Participants were classified into three groups depending on the total number of natural teeth (excluding third molars): full dentition (28 teeth), moderate dentition (21-27 teeth), and poor dentition (20 teeth or less). Dietary intake and diet quality were estimated from the first 24-h dietary recall data. RESULTS: Participants in the poor dentition group had significantly lower energy intake than those with moderate dentition (P<0.05), however, both groups did not significantly differ from those who had full dentition. Adjusting for sociodemographic characteristics, physical activity, smoking status, and energy intake, the intake of protein as well as most vitamins and minerals were positively associated with the total number of natural teeth (P<0.05); an inverse association was observed for carbohydrate intake (P<0.001). Diet quality, as measured by the Healthy Eating Index 2005, was inversely associated with tooth loss (P<0.001). CONCLUSIONS: Tooth loss in adults is associated with lower diet quality and reduced intake of most nutrients; this may partly explain for the higher risk of chronic diseases in this population. CLINICAL SIGNIFICANCE: People with missing teeth are recommended to monitor their dietary intake to avoid nutrient deficiency and to improve their diet quality for better health.

Modified sham feeding of foods with different macronutrient compositions differentially influences cephalic change of insulin, ghrelin, and NMR-based metabolomic profiles.

Little is known about the effect of the macronutrient composition of foods on cephalic phase response of gastrointestinal hormones. In addition, the metabolomics of cephalic phase response has not been studied before. The objective of the present study was to assess cephalic phase endocrinological and metabolomic responses following modified sham feeding (MSF) of foods with different macronutrient compositions. Ten healthy males attended four separate test sessions after overnight fasting, for a 3-min MSF of water, high-fat, high-carbohydrate or high-protein food, respectively, in a randomized order. Blood samples were collected at baseline and at regular time points for 10min following the completion of MSF and assayed for plasma glucose, insulin, ghrelin and glucose-dependent insulinotropic peptide. (1)H nuclear magnetic resonance was used to acquire metabolomic profiles of the plasma samples. Plasma glucose increased after MSF of all test foods, but there were no differences due to the macronutrient composition of the test foods. MSF of the high-carbohydrate food elicited significantly higher insulin, and the high-protein food resulted in higher ghrelin compared to other test sessions. No significant change in glucose-dependent insulinotropic peptide was found. Analysis of plasma metabolomic profiles revealed concentrations of lipids were lower after MSF while plasma glucose increased after MSF. There was also a macronutrient-dependent change in certain amino acids. In conclusion, short-term oral exposure to foods with different macronutrient compositions can induce a macronutrient-specific cephalic change in insulin and ghrelin, as well as metabolomic profiles.

Increased number of chews during a fixed-amount meal suppresses postprandial appetite and modulates glycemic response in older males.

Aging is associated with a reduction in appetite. Older adults require a higher number of chews to form a bolus before swallowing. However, whether this ingestive behavior contributes to the reduced appetite in this population is unknown. Fifteen males aged 65 years or older participated in this randomized cross-over trial and attended two test sessions. After an overnight fast, they consumed a fixed-amount meal (2050 kJ) by chewing each portion of food 15 or 40 times before swallowing. Subjective appetite was measured using visual analogue scales at regular intervals for 3 h after completion of the meal. Blood samples were collected at the same time for measurement of glucose, insulin, and glucose-dependent insulinotropic peptide (GIP). Participants were provided an ad libitum meal 3 h later. Compared with 15 chews, chewing food 40 times before swallowing resulted in significantly lower postprandial hunger (P=0.003), preoccupation with food (P<0.001), and desire to eat (P<0.001). Plasma concentrations of glucose, insulin, and GIP were significantly higher at meal completion when 40 chews were made (all P<0.01), and became significantly lower during the late postprandial period (all P<0.05). Food intake at the subsequent ad libitum meal did not differ significantly between test sessions. Our findings suggested that increased number of chews reduced postprandial hunger and desire to eat, and modulated glucose metabolism in older males. The number of chews made during a fixed-amount meal may influence short-term appetite; how this ingestive behavior contributes to energy balance in the long term warrants further investigation.

Gastric emptying rate, glycemic and appetite response to a liquid meal in lean and overweight males.

The effect of body weight status on appetite, glycemic response and gastric emptying rate was investigated using a liquid meal. Lean and overweight males rated their subjective appetite with blood samples collected for measurement of glucose, biomarkers of appetite and gastric emptying rate for 3 h following consumption of the isocaloric test meal. Overweight participants had a higher rating on postprandial hunger (p < 0.001), preoccupation with food (p < 0.001) and desire to eat (p < 0.001), with fullness being lower (p = 0.001). Postprandial plasma concentration of cholecystokinin-33 was lower (p = 0.007) and total ghrelin was higher (p = 0.012) in overweight participants. A delayed gastric emptying rate was observed in lean participants. There was no difference in postprandial glycemic response (p = 0.189). These results suggest the postprandial appetite pattern was different between lean and overweight males when consuming an isocaloric meal. This may have implications for overweight individuals who attempt to lose weight through restricting food intake.