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Objective: To examine the associations of physical activity (PA) and sitting time (sit) with cardio-metabolic diseases. Methods: Cross-sectional data from the Australian National Nutrition and Physical Activity Survey 2011–2012 (n=9,435) were used to classify adults into low and high risk groups based on their physical activity and sitting behaviour profiles. Logistic regression models examined associations between low and high risk classifications (high PA-low sit; high PA-high sit; low PA-low sit; low PA-high sit;) and socio-demographic factors, and associations between low and high risk classifications and the prevalence of cardiovascular disease, Type 2 diabetes and metabolic syndrome. Results: These results characterise chronic disease risk based on both physical activity and sitting behaviour. Adults with the highest risk lifestyle behaviour pattern (low PA-high sit) tended to be middle aged, male, at greater social disadvantage, smoke, report fair health, be abdominally obese and employed in administrative and driver occupations. These individuals had a substantially greater risk of cardiovascular disease and metabolic syndrome (OR=1.41, 95% CI 1.13, 1.75; OR= 2.37, 95% CI 1.63, 3.45, respectively). Conclusions: The findings highlight the importance of both sufficient physical activity and low sitting time for cardio-metabolic health. Implications for public health: Primary prevention focus should consider physical activity and reduced sitting time as well as provision of relevant advice for cardio-metabolic health.

This study evaluated the effects of sit-stand desks on workers' objectively and subjectively assessed sitting, physical activity, and productivity. This quasi-experimental study involved one intervention group (n = 16) and one comparison group (n = 15). Participants were call center employees from two job-matched teams at a large telecommunications company in Sydney, Australia (45% female, 33 ± 11 years old). Intervention participants received a sit-stand desk, brief training, and daily e-mail reminders to stand up more frequently for the first 2 weeks post-installation. Control participants carried out their usual work duties at seated desks. Primary outcomes were workday sitting and physical activity assessed using ActivPAL or ActiGraph devices and self-report questionnaires. Productivity outcomes were company-specific objective metrics (e.g., hold time, talking time, absenteeism) and subjective measures. Measurements were taken at baseline, 1, 4, and 19 weeks post-installation. Intervention participants increased standing time after 1 week (+ 73 min/workday (95% CI: 22, 123)) and 4 weeks (+ 96 min/workday (95% CI: 41, 150)) post-intervention, while control group showed no changes. Between-group differences in standing time at one and 4 weeks were + 78 (95% CI: 9, 147) and + 95 min/workday (95% CI: 15, 174), respectively. Sitting time in the intervention group changed by − 64 (95% CI: − 125, − 2), − 76 (95% CI: − 142, − 11), and − 100 min/workday (95% CI: − 172, − 29) at 1, 4, and 19 weeks post-installation, respectively, while the control group showed no changes. No changes were observed in productivity outcomes from baseline to follow-up in either group. Sit-stand desks can increase standing time at work in call center workers without reducing productivity., Highlights • Few workplace sitting interventions have involved objective productivity outcomes. • This sit-stand desk intervention increased standing time in call center workers (73–90 min/workday). • Sitting time decreased in the intervention group (64–100 min/workday). • Using sit-stand desks at work did not change call center workers’ productivity (e.g., talking time, hold time).

In the oral cavity, the food is subjected to several mechanical and chemical processes. It is fractured by the teeth, diluted and broken down by saliva, heated or cooled by the ambient temperature of the mouth, formed into a bolus and finally swallowed. Numerous receptors in the oral cavity and nose respond to the initially ingested food and monitor the changes during processing. This leads to central perceptions of taste, odor, irritation and texture of the food. Most sensations associated with food texture occur only when the food is manipulated, deformed or moved across the oral receptors. In addition, people assessing the same stimulus differ in their ratings of that stimulus and their oral physiological parameters also exhibit inter-individual variations. This paper is based on the PhD thesis of one of the authors. It gives an overview of this study and includes related work of other authors. The aim of our research was to improve the understanding of oral texture perception, in particular to examine the role of oral physiological processes in oral texture perception of semisolids and to investigate whether individual differences in perception could be attributed to differences in oral physiology among subjects. The results of our study demonstrate that oral physiological parameters such as oral sensitivity, tongue movements, temperature and saliva composition are of importance for texture perception of semisolids. Many parameters of oral physiology correlate with various perceived texture attributes. This implies that intra-individual differences in texture perception could be attributed to variations in oral physiology. Oral physiology thus plays a role in texture perception of semisolids and should be taken into account in future texture research. PRACTICAL APPLICATIONS By understanding the processes in the mouth while eating, a better understanding of the sensations and the perceptions of the food can be gained. Taking for each food the relevant physiological parameter into consideration when performing and designing rheological/instrumental measurements grants more natural conditions and better predictions of sensory perception. This could save time and money on time-consuming and expensive sensory panels in the earlier steps of product development and renovation. Knowing how physiological processes highlight specific flavor/texture sensations may be useful for product development or quality control where one typically wants to focus on certain sensations and ignores others. In addition, a future application could be to tailor products for personalized nutrition, individual choices or clinical nutrition based on physiological groups.

The production of a sufficient amount of saliva is indispensable for good chewing. In the present study, we examined the hypothesis that adding fluid to a food will facilitate the chewing process, especially for dry foods. The effect might be larger for subjects with relatively low salivary flow rates. Furthermore, adding fluids that contain mucins or alpha-amylase may have a larger facilitating effect on mastication than the addition of water alone. Twenty subjects chewed on melba toast, breakfast cake, carrot, peanut, and Gouda cheese. In addition, they chewed on these foods after different volumes of water, artificial saliva containing mucins, or a solution of alpha-amylase had been added. Muscle activity and number of chewing strokes until swallowing were measured. The salivary flow rates of the subjects were also determined. Adding fluid to the food significantly reduced the number of chewing cycles and total muscular work (i.e. the integrated surface electromyograpy of masseter and temporalis muscles measured bilaterally, summed for all chewing cycles) until swallowing for all foods, except carrot. The largest effects were observed for melba and cake, which are dry products requiring sufficient saliva to form a coherent bolus safe for swallowing. More facilitation of the chewing process was observed after adding fluid to breakfast cake for subjects with relatively low salivary flow rates. The type of fluid had no significant effect on the chewing process.

introduction: The production of sufficient saliva is indispensable for good chewing. Recent research has demonstrated that salivary flow rate has little influence on the swallowing threshold. Objectives: The hypothesis examined in the present study was that adding fluids to foods will influence chewing physiology. Materials and Methods: Twenty subjects chewed on melba toast, cake, carrot, peanut and Gouda cheese. They also chewed on these foods after addition of different volumes of water or alpha-amylase solution. Jaw muscle activity, number of chewing cycles until swallowing and chewing cycle duration were measured. Repeated measures analysis of variance was applied to test the null hypothesis that there would be no statistically significant difference among the results obtained for the various food types and fluids. Subsequently, contrasts were determined to study the levels of intra-subjects factors (food type and fluid volume). Linear regression was used to determine the changes in muscle activity and cycle duration as a function of the chewing cycles. Results: Fluid addition significantly decreased muscle activity and swallowing threshold for melba, cake and peanut (p 0.05). Doubling the volume of tap water had a greater effect. Conclusions: Fluid addition facilitated chewing of dry foods (melba, cake), but did not influence the chewing of fatty (cheese) and wet products (carrot). This study is relevant to improve patients' life quality and the management of chewing and feeding disorders caused by hyposalivation.

Background:Australia has joined a growing number of nations that have evaluated the physical activity and sedentary behavior status of their children. Australia received a “D minus” in the first Active Healthy Kids Australia Physical Activity Report Card.Methods:An expert subgroup of the Australian Report Card Research Working Group iteratively reviewed available evidence to answer 3 questions: (a) What are the main sedentary behaviors of children? (b) What are the potential mechanisms for sedentary behavior to impact child health and development? and (c) What are the effects of different types of sedentary behaviors on child health and development?Results:Neither sedentary time nor screen time is a homogeneous activity likely to result in homogenous effects. There are several mechanisms by which various sedentary behaviors may positively or negatively affect cardiometabolic, neuromusculoskeletal, and psychosocial health, though the strength of evidence varies. National surveillance systems and mechanistic, longitudinal, and experimental studies are needed for Australia and other nations to improve their grade.Conclusions:Despite limitations, available evidence is sufficiently convincing that the total exposure and pattern of exposure to sedentary behaviors are critical to the healthy growth, development, and wellbeing of children. Nations therefore need strategies to address these common behaviors.

Background:Children can spend substantial amounts of leisure time in sedentary activities, dominated by TV/screen time. However, objective real-time measurement of activities after school among young school children is seldom described.Methods:School children (n = 246, 5−7 years old, mean 6.0) and their parents were recruited by random selection from 14 schools across Sydney, Australia. Parents used a real-time objective measure (Experience Sampling Method, ESM) to record children’s activities and whether they were indoors or outdoors at 3 random times each day after school. Data were collected across 4 weekdays in 1 week and then, 13 weeks later, another 4 weekdays in 1 week.Results:Results were based on 2940 responses from 214 childparent dyads showed that 25% of behavior involved physical activity, 51% was spent in sedentary activities, and 22% was TV/ screen time. Most instances (81%) occurred indoors.Conclusion:Despite a high proportion of TV/screen time, children were also engaged in a range of other sedentary and physically active pursuits after school. Hence TV/screen time is not a suitable proxy for all sedentary behavior, and it is important to gather information on other non–screen-based sedentary and physically active behaviors. Future research is warranted to further investigate after-school activities in young primary school children.

This review addresses a fundamental neuroscientific question in food perception: how multimodal features of food are integrated. Much research and conceptualization has emerged related to multisensory integration in vision, audition and somatosensation, while it remains poorly understood and researched within the chemical and mouth feel senses. This review aims to bridge this gap. We discuss the main concepts in the fields of auditory, visual and somatosensory multisensory integration and relate them to oral-sensory (gustatory and somatosensory) and olfactory (orolfactory) interactions. We systematically review the psychophysical literature pertaining to intra- and intermodal interactions related to food perception, while making explicit distinctions between peripheral and central interactions. As the neural bases of crossmodal orolfaction currently are poorly understood, we introduce several plausible neuroscientific models, which provide a framework for further neuroscientific exploration in this area. We are guided by a new meta-analysis of the odor-taste neuroimaging literature, as well as by single-unit, anatomical and psychophysical studies. Finally, we propose strong involvement of recurrent neural networks in multisensory integration and make suggestions for future research.

We investigated how different parameters affect oral size perception of small particles of SiO 2 and polystyrene particles of varying sizes (2-230 μm). Eighteen healthy subjects assessed the size of the particles by rubbing the sample between the tongue and the palate. The importance of size and type were studied by direct scaling and forced choice ranking and the results of the two methods were compared. To assess the relative importance of the tongue and the palate in oral size perception topical anesthesia was applied. The size and characteristics of particles are of importance for perception of particle size, where hard and irregular particles are perceived as larger than soft and round particles of similar size. The two methods of size perception, direct scaling and forced ranking produce very similar results on oral size perception. Topical anesthesia of either the tongue or the palate had no significant effect.

The effects of nonoral sensations, such as visual texture and odor, on the size of the first bite were investigated in a series of studies using specially constructed food delivery cups with lower, from which custards were ingested ("ingested custard"), and upper, from which a custard was viewed and/or smelled ("upper custard") compartments. Ingested and upper custards were either the same or different. Bite size was defined as the weight of custard sucked out of the lower compartment during a single suck through an I I -mm diameter straw. The results from the first study indicated that the recognition of oral qualities of custards via vision or olfaction determined the size of the first bite. When this recognition was favorable, e.g., when the upper custard was known to be creamy, a relatively large bite was taken, irrespective of the custard that was actually ingested. When this recognition was unfavorable, a relatively small bite was taken. The second study showed that when recognition was prevented by modifications of the upper custard's color, odor, or visual texture, bite size was determined by the oral qualities of the ingested custard. This was confirmed in a third study, where the oral characteristics of the ingested custard were varied by adding a flavorant (benzaldehyde) and/or by using nose clips to eliminate retronasal smelling. Bite sizes decreased significantly when these variations reduced creaminess. Odor and visual texture characteristics of the upper custard significantly affected the perception of creaminess and other attributes related to the food's viscosity, melting, and thickness. (C) 2004 Elsevier Inc. All rights reserved.

The size of a bolus determines how it will be manipulated in the mouth and swallowed. We hypothesized that mucosal sensitivity would be important for masticatory function. The accuracy of solid object size perception, spatial acuity, and food particle size reduction during mastication were measured in 22 healthy adults with/without topical anesthesia of their oral mucosa. Topical anesthesia had no effect on the perception of sphere sizes, but significantly reduced spatial sensitivity. Without anesthesia, there was a correlation between an individual’s ability to perceive the sizes of steel spheres (diameter, 4–9 mm) and the sizes of food particles chewed for 15 cycles and at swallowing. There was no correlation between spatial sensitivity and food particle size. We suggest that the stimuli used to test two-point discrimination stimulates only superficial receptors, which involve light touch and are easily anesthetized, while the spheres might excite more deeply-set receptors. The latter appear to be more important for masticatory performance and swallowing.

We determined the salivary flow rate in 16 healthy subjects in rest and while chewing artificial and natural foods (Parafilm, Melba toast with and without margarine, and three different volumes of breakfast cake and cheese). We also determined the duration of a chewing cycle, the number of chewing cycles until swallowing, and the time until swallowing. The physical characteristics of the foods were quantified from force-deformation experiments. The flow rates of the saliva as obtained without stimulation, with Parafilm stimulation, and with chewing on the various foods were significantly correlated. An increase in chewing cycle duration, number of chewing cycles until swallowing, and time until swallowing was observed as a function of the volume of the food. More chewing cycles were required for Melba toast than for an equal volume of cake or cheese. This may be caused by the low water and fat percentage of the Melba toast. The number of chewing cycles and the time until swallowing significantly decreased when the Melba toast was buttered. The decrease may be caused by facilitation in bolus formation and lubrication of the food due to buttering the toast. The number of chewing cycles until swallowing was not correlated to the salivary flow rate.

Salivary flow rates were measured at rest and after three types of stimulation; odor, Parafilm chewing, and citric acid. The highest flow rate was elicited by citric acid followed by Parafilm and odor, while the lowest flow rate was unstimulated. In order to investigate whether and how the amount of saliva a subject produces influences the sensory ratings, the four types of salivary flow rates were correlated with sensory ratings of three different types of vanilla custard dessert. No significant correlation could be found between any of the salivary flow rates and the sensory ratings. A subject with a larger saliva flow rate during eating did not rate the foods differently from a subject with less saliva flow. The same pattern was seen for all types of stimulation. This finding could indicate that subjects are used to their respective amounts of saliva to such a degree that the differences in sensory ratings between subjects cannot be explained by the interindividual difference in saliva flow rate.

This work examined the influence of oral temperature on oral perception of temperature in liquids and semisolids. A panel of 20 adults assessed the temperature of water, custard dessert and mayonnaise. Oral temperatures were manipulated by 5-s mouth rinses of 10, 35 and 55 degrees C performed prior to assessments, which resulted in oral temperatures of 27, 35 and 43 degrees C, respectively. The products were evaluated at 10, 22 and 35 degrees C. Results show that subjects were able to differentiate between the product temperatures. A large effect of type of product was seen on perceived temperature, where water was, overall, perceived as significantly colder than custard dessert and mayonnaise. The range of perceived thermal ratings was widest for custard dessert, followed by water and mayonnaise. This might be due to differences in composition and structure of the products. Even though oral temperature was varied considerably in the present study, this did not exert large effects on perceived temperature.

The size of a bolus determines how it will be manipulated in the mouth and swallowed. Ten healthy individuals assessed the size of ball bearings of five sizes (4-11 mm diameter) and four materials with different densities in order to investigate the effect of weight on oral size perception. To study the role of the tongue and palate, the experiment was performed with and without a custom-made plastic palate. The results revealed that size itself determines size perception, and that material and weight are negligible factors. An illusional effect in the direction of under-estimation was found for the ball bearings, especially for the small sizes up to 8 mm diameter. While wearing a plastic palate a significant improvement (P0.05) occurred; the participants performed better and there was less under-estimation. An explanation for this could be that only a minor part of the total area of the ball bearing touches the palate and is hence detected, while the tongue alone is more compliant and thereby able to sense the ball's whole size.

Background:Like many other countries, Australia is facing an inactivity epidemic. The purpose of the Australian 2014 Physical Activity Report Card initiative was to assess the behaviors, settings, and sources of influences and strategies and investments associated with the physical activity levels of Australian children and youth.Methods:A Research Working Group (RWG) drawn from experts around Australia collaborated to determine key indicators, assess available datasets, and the metrics which should be used to inform grades for each indicator and factors to consider when weighting the data. The RWG then met to evaluate the synthesized data to assign a grade to each indicator.Results:Overall Physical Activity Levels were assigned a grade of D-. Other physical activity behaviors were also graded as less than average (D to D-), while Organized Sport and Physical Activity Participation was assigned a grade of B-. The nation performed better for settings and sources of influence and Government Strategies and Investments (A- to a C). Four incompletes were assigned due to a lack of representative quality data.Conclusions:Evidence suggests that physical activity levels of Australian children remain very low, despite moderately supportive social, environmental and regulatory environments. There are clear gaps in the research which need to be filled and consistent data collection methods need to be put into place.

Background:To promote healthy lifestyles, we need to understand more about the patterns of children’s activities after school.Methods:Twenty 5- to 7-year-old children and their parents participated in this study. Parents used ‘real-time’ diaries to report children’s activities and contextual information at 3 randomly selected times per day, over 4 week days. Reporting was repeated after 13 weeks. Simultaneously children wore Actical accelerometers.Results:Approximately 300 simultaneous accelerometer measurements and diary entries were compared. Mean physical activity levels were highest when children engaged in activities generally considered as “active” and lowest for doing “nothing.” However, the range within activities was very large; some children who reported TV/screen time accumulated high accelerometry counts and conversely, some children were practically sedentary during organized sports. Children spent most (78%) of their after school time indoors, but the children were significantly more active outdoors than indoors [t(74.8) = 5.0, P < .001].Conclusions:Accelerometer data in conjunction with real-time diaries provide a more complete understanding of the value of outdoor play in increasing movement opportunities for children’s after school activities.

Workplace physical activity programs can motivate inactive target groups to increase daily activity levels, but it is important to determine their reach and impact.The Global Corporate Challenge (GCC) is a team-based program promoting pedometer-based self-monitoring to reach 10000 steps per day. Participants (n = 587) from an Australian university were recruited and recorded their daily step counts. Demographic, anthropometric, behavioural, self-reported physical activity and sitting time data were collected at baseline and following the 16-week program.On average, participants self-estimated 11 638 daily steps in Week 1, increasing to measured estimates of 13 787 daily steps in Week 16 (P0.001). At baseline, 92% of survey completers were already meeting the physical activity recommendations, increasing to 98% (P = 0.059) at follow-up. Four month improvements in objectively assessed anthropometric measures showed small, non-significant reductions in weight (-0.12 kg; P = 0.416), body mass index (-0.06 kg/m2; P = 0.314) and waist circumference (-0.43 cm; P = 0.082). Sitting time during work decreased significantly by 21 min per day (P0.001) and participants with initially low levels of sitting time at work were more likely to increase their step counts during the GCC (adjusted odds ratio 1.90, 95% confidence interval 1.03-3.50).Although this pedometer-based program resulted in increases in physical activity and reductions in occupational sedentary behaviour, most participants were already meeting physical activity recommendations at baseline. SO WHAT? Workplace interventions need to be better targeted to reach inactive employees to have population-level impacts on chronic disease risk factors.

This study finds that obesity has increased more rapidly in Aboriginal than non-Aboriginal children in New South Wales, but that strategies to limit screen time hold promise. Abstract Objectives: To report 13-year trends in weight status of Australian Aboriginal children, and to describe weight-related behaviour in children in 2010, by Aboriginality. Design, setting and participants: Cross-sectional population surveys of children aged 5–16 years (n = 18 983) conducted in New South Wales schools in Term 1 of 1997, 2004 and 2010. Main outcome measures: For trend analysis: body mass index and waist-to-height ratio (WtHr). Analyses of weight-related behaviour from 2010 survey data included indicators of dietary habits, screen time (ST) and physical activity. Results: Between 1997 and 2010, the relative increase in prevalence of overweight/obesity and WtHr ≥ 0.5 was 22.4% and 113.6%, respectively, among Aboriginal children, and 11.8% and 3.4%, respectively, among non-Aboriginal children. In 2010, Aboriginal children had 1.52 (95% CI, 1.03–2.24) greater odds of having a WtHr ≥ 0.5 than non-Aboriginal children. Compared with non-Aboriginal children, Aboriginal children also had significantly lower odds of eating breakfast daily (adjusted odds ratio [AOR], 0.72; 95% CI, 0.52–0.99) and significantly greater odds of drinking ≥ 1 cup of soft drink daily (AOR, 1.61; 95% CI, 1.13–2.29), having a television in their bedroom (AOR, 2.75; 95% CI, 2.04–3.70), having no ST rules (AOR, 1.34; 95% CI, 1.04–1.73) and exceeding ST recommendations on weekdays (AOR, 1.78; 95% CI, 1.32–2.39). Conclusions: Overweight/obesity and WtHr have increased more rapidly in Aboriginal than non-Aboriginal children in NSW. Unhealthy weight-related behaviour was frequent among all children, but lack of daily breakfast, excessive ST and soft drink consumption appear particularly problematic among Aboriginal children. Raising awareness with families of the consequences of excessive ST and encouraging strategies to limit ST (such as rethinking placement of televisions in children's bedrooms and implementing ST rules) hold promise.

Background:After-school hours provide an opportunity for physical activity (PA). Parental perceptions influence children’s PA. The aims were to: compare parents’ perceptions of children’s PA with objectively measured PA; shed light on PA during after-school hours; and compare two electronic devices for collecting data.Methods:Twenty parent-child dyads participated. Children (5–7 years, mean 6.25 ± 0.64) wore Actical accelerometers; their parents responded to activity diaries on electronic devices. Data were collected twice for 4 consecutive weekday afternoons (15.30–19.00).Results:While parents perceived their children to be quite active, children were, in fact, largely inactive. Parents’ responses compared with accelerometer data yielded moderate correlations (r = .44, p < .01). Two thirds of parents’ responses were overestimations. Boys were physically more active than girls and had higher PA outdoors than indoors. Girls’ PA remained similar indoors and outdoors but parents did not perceive the similarity. Both electronic devices produced similar results and compliance rates.Conclusion:Parents consistently over-reported their children’s PA. Findings have implications for initiatives to increase PA. If parents perceive their children as very active, they may lack motivation to promote PA. Parents’ limitations as proxy reporters aside, the similarity of results yielded by the two electronic devices suggests that the choice is a matter of researcher preference.

Saliva is expected to be of significance for the perception of food stimuli in the mouth. Mixing the food with saliva, including breakdown and dilution, is considered to be of large importance for semi-solids as these products are masticated without chewing. It is known that there are large variations in composition of saliva originating from different glands and different subjects. In this study we investigated how variations in salivary characteristics affect sensory perception. Eighteen trained subjects participated in the study. Saliva was collected at rest and during three types of stimulation (odour, parafilm chewing and citric acid), and flow rates were determined. The collected saliva was analyzed for protein concentration, buffer capacity, mucin level and α-amylase activity. The salivary components measured in this study varied considerably among subjects, but also within subjects as a result of different means of stimulation. Variations in salivary components were correlated with sensory perception of a number of flavour, mouth feel and after feel attributes in the semi-solids mayonnaise and custard dessert. Total protein concentration and α-amylase activity were observed to correlate most strongly with texture perception. © 2006 Elsevier Ltd. All rights reserved.

It has been generally assumed that fat is detected by its flavour and by its lubrication of the oral mucosa. A recent study reported a correlation of -.99 between perceived temperature of a product and its fat content. This was significantly higher than correlations of sensory scores for fat flavour, mouthfeel, and afterfeel. This suggested a third detection mechanism; fat may be detected via its effect on the thermal conductivity of the food. In 3 studies, thermal sensitivity in humans was investigated to verify whether oral thermal receptors are sufficiently rapid and accurate to play a role in the perception of fats. The thermal sensitivity of the lips and oral mucosa of the anterior and middle one-third of the tongue were assessed using a Peltier device. Subjects detected 0.5 Hz fluctuations in temperature of 0.08°C on the lower lip, 0.26°C and 1.36°C at the tip and dorsum of the tongue, demonstrating that the lips are sufficiently sensitive to detect small differences in temperature. In two further experiments subjects ingested custards and mayonnaises and then spat out samples after 5, 10, or 20 sec. The temperature of the food and oral mucosa was measured before and after spitting and the rates of heating were calculated. Results suggest assessment of thermal conductivity of food may be used to assess fat content. © Perceptual and Motor Skills 2007. Chemicals / CAS: Dietary Fats

Background: Prolonged sitting is a specific occupational hazard in office workers and there is growing evidence that prolonged sitting is detrimental to metabolic health. Purpose: The aim of this study was to determine whether providing officeworkerswith an adjustable sit-standworkstation together with targeted education, or targeted education alone would lead to changes in sedentary behaviour at work compared with no intervention. Methods: A randomized control trial with three groups. We recruited 60 academic and administrative university employeeswhose normal role involved>15 hours perweek of computer work. Participants were randomised to one of three groups as described below. The intervention period was four weeks. Group 1: Education based on “The Happy Body at Work’ program Group 2: The same education program as Group 1 and provision of an adjustable sit-stand workstation Group 3: No intervention control The primary outcome was the average daily sedentary time during work hours. Participants wore an accelerometer during working hours for five working days prior to randomisation, then for another five days at four week follow up. Secondary outcomes included self-report of sitting behavior using Occupational Sitting and Physical Activity Questionnaire (OSPAQ). Mixed models analysis was performed for continuous variables comparing the average outcome score at baseline and follow-up between random allocation groups. Cohen’s D was used to measure the magnitude of these differences. For the categorical outcomes, there was a low number of participants who changed pain/disability status between baseline and follow-up overall therefore descriptive and nonparametric statistics (Fishers Test) were used to examine differences in change in pain/disability profiles between random allocation groups. Results: Data from 59 participants were available for the mixed model analysis. No significant differences were found between both intervention groups and the control group in any primary or secondary outcome. However, consistently large effect size (Cohen’s D) differences were observed between the groups favouring the combined education/sitstand workstation intervention. For this group, subjective but not objectively measured sitting time per work day, and per work week, (OSPAQ) were respectively 65 and 369minutes less at follow up compared to baseline (Cohen’sD−0.61 and −0.69, p< 0.01 for both). No significant within group difference in these outcomes was found for either the education only intervention or the control group. Conclusion(s):While not significant, the trend in the data favouring the combined intervention is in line with the effects found by other recently published studies evaluating the use of similar activity permissive workstations. Implications: To effect positive change in sedentary behaviour in non-motivated individuals a longer adoption period may be required together with regular promoting and reinforcement to increase adherence.

Mastication is a sensory-motor activity aimed at the preparation of food for swallowing. It is a complex process involving activities of the facial, the elevator and suprahyoidal muscles, and the tongue. These activities result in patterns of rhythmic mandibular movements, food manipulation and the crushing of food between the teeth. Saliva facilitates mastication, moistens the food particles, makes a bolus, and assists swallowing. The movement of the jaw, and thus the neuromuscular control of chewing, plays an important role in the comminution of the food. Characteristics of the food, e.g. water and fat percentage and hardness, are known to influence the masticatory process. Food hardness is sensed during mastication and affects masticatory force, jaw muscle activity, and mandibular jaw movements. When we chew for instance a crispy food, the jaw decelerates and accelerates as a result of resistance and breakage of food particles. The characteristic breakage behaviour of food is essential for the sensory sensation. This study presents a short review of the influence of oral physiology characteristics and food characteristics on the masticatory process.

The urge to swallow food could be triggered by a threshold level in both food particle size and lubrication of the food bolus. Thus, both oral physiology and product characteristics may influence the swallowing threshold. We quantified the swallowing threshold in a group of 266 healthy adult subjects (age 42 +/- 12 years) by counting the number of chewing cycles needed to prepare food for swallowing. The influence of oral physiology on the swallowing threshold was determined by measuring salivary flow rate, maximum bite force and masticatory performance. We used about 10 cm(3) of bread, toast, melba toast, breakfast cake, peanuts and cheese to determine the influence on the swallowing threshold of various food characteristics, e.g. hardness, moisture and fat. Furthermore, we tested the effect of buttering the bread, toast, melba toast and breakfast cake on the swallowing threshold. Salivary flow rates were significantly and negatively correlated with the number of chewing cycles of melba toast and breakfast cake. Hence, subjects with more saliva needed less chewing cycles for these dry products. Maximum bite force and masticatory performance had an influence on the swallowing threshold for the hard products only (carrot and peanut). Although significant, the correlation coefficients were less than 0.28. Thus, the oral physiology parameters explained less than 10% of the variance in the swallowing threshold. We found significantly different numbers of chewing cycles for the various foods, ranging from 17 for cake to 63 for carrot. Hard and dry products needed more chewing cycles until swallowing. Buttering the food significantly reduced the number of chewing cycles needed before swallowing. This was especially true for the dry products cake, melba toast and toast. Hard and dry products require more chewing cycles and longer time in mouth until swallowing for sufficient breakdown to take place and for enough saliva to be added to form a coherent bolus safe for swallowing. In spite of this, more saliva, higher maximum bite force and better masticatory performance were only weakly correlated with a smaller number of chewing cycles. Butter enhanced lubrication and bolus formation of dry products, thus reducing the number of chewing cycles until swallowing. In conclusion, product characteristics and to a lesser extent oral physiology significantly affect swallowing threshold.

The role of salivary a-amylase in odour, flavour, and oral texture sensations was investigated in two studies in which the activity of salivary amylase present in the mouth of human subjects was either increased by presenting custards with added alpha-amylase or decreased by presenting custards with added acarbose, an amylase inhibitor. For starch-based vanilla custard desserts, amylase resulted in increased melting and decreased thickness sensations, whereas acarbose had the opposite effect, i.e., decreased melting and increased thickness. Other affected attributes included creamy mouth feel, creamy after feel, and fatty after feel. Creaminess, which is considered to be a highly desirable food quality, decreased by as much as 25% with added amylase and increased by as much as 59% with added acarbose. Neither additional amylase nor acarbose affected sensations for a nonstarch-based carboxy methylcellulose (CMC) vanilla custard dessert. This indicates that the effects of amylase on viscosity-related sensations of starch-based custards, such as perceived melting and thickness, are caused by amylase-induced breakdown of starch. Partial Least Square (PLS) analysis indicated that the effects of amylase and acarbose on perceived creaminess are not only driven by their effects on perceived melting and thickness, but also by their effects on perceived flavour. (C) 2004 Elsevier Inc. All rights reserved.

Practically all foods contain particles. It has been suggested that the presence of particles in food may affect the perception of sensory attributes. In the present study we investigated the effect of size and type (hardness and shape) of particles added to a CMC based vanilla custard dessert. The two types of particles included in the study were silica dioxide and polystyrene spheres, varying in size from 2 to 230 microm. Eighteen trained adults participated in the study. They rated the sensation of 17 sensory flavour and texture attributes on a 100-point visual analogue scale (VAS). The results indicate that the addition of particles increased the sensation of roughness attributes and decreased the ratings of a number of presumably favorable texture attributes (smoothness, creamy, fatty and slippery) significantly. These effects increased with increasing particle size up to 80 microm. Roughness ratings deceased for larger particles sizes. Surprisingly, even particles of 2 microm had significant effects: they increased perceived rough lip-tooth feel, and decreased slippery lip-tooth feel and smoothness of the product. The affected attributes had previously been related to lubricative properties of foods. Particles added to semi-solid foods with relatively low levels of fat seem to counteract the lubricating effects of the fat resulting in increased oral friction. In a separate study on size perception the silica dioxide particles were used. By sampling the stimuli between the tongue and palate, subjects rated the size of the particles on a 100-point scale in comparison to anchor stimuli containing no particles and particles of 250 microm. The perceived particle size significantly increased for larger particles. Furthermore, perceived particle size was negatively correlated with roughness ratings. Thus, subjects who were sensitive and perceived the particles as being relatively large reported the same stimuli to have less rough after-feel. In conclusion, particles added to a product induce large effects on texture sensations, and texture sensation is related to individual size perception.

This study examined the effect of oral and product temperature on the perception of texture and flavor attributes. A trained panel assessed 21 texture and flavor attributes in one high-fat and one low-fat product of two semi-solids: custard dessert and mayonnaise. The products were evaluated at 10, 22 or 35°C in combination with oral temperatures of 27, 35 and 43°C. Results showed that modulation of product and oral temperature had significant effects on a number of attributes. Flavor intensities, melting mouth feel, and fat after feel increased, while subjective thickness decreased with increasing product temperature. Neither product- nor oral temperature had an effect on over-all creaminess. Oral temperature affected a number of mouth feel attributes: melting, heterogeneous and smooth. Furthermore, large differences existed in ratings between the high- and low-fat products of custard and mayonnaise, and they were more prominent in mayonnaise. We conclude that the effect of oral temperature on the perception of sensory attributes in semi-solids was small, but present, while the product temperatures influenced the ratings greatly. © 2003 Elsevier Ltd. All rights reserved.

To gain insight into the effect of oral processes on perception, we defined a set of five specific oral manipulations and investigated their effects on the perception of low and high fat versions of two semi-solid foodstuffs, vanilla custard desserts and mayonnaises. Behavior modifications ranged from simply placing the stimulus on the tip of the tongue to vigorously moving it around in the mouth. Sensory ratings for mouth-feel and flavor attributes were made 5 s after placing the stimulus in the mouth, and after-feel attributes were rated immediately after swallowing. Most attributes showed a similar pattern, with lowest attribute ratings where the tongue's movement was restricted and gradually increasing ratings with increasing complexity of the tongue movements. An individual's normal oral processing behavior typically resulted in the most intense sensations of flavor and mouth-feel. Residence time for all mouth-feel attributes, except prickling, was determined by the time required for tongue movements. The exact tongue movements required for sensations appeared to be related to food groups and individual foods, rather than to specific mouth-feel attributes.

The influence of bite size on sensory mouthfeel and afterfeel sensations was explored in two studies in which single bites of vanilla custard desserts were varied from 2 to 11 mL (study 1) and in which series of five bites of two different custard desserts were presented consecutively (study 2). In single bites, sensations of perceived creaminess were enhanced with size whereas sensations of astringency and temperature were suppressed. Bite size also affected perceived thickness, but the direction of the effects varied with custard desserts. With multiple bites, creaminess sensations continued to increase, whereas other sensations were unaffected. Switching to a second series of bites of another vanilla custard dessert showed larger sensory effects, especially on astringency sensations but also to a lesser extent on sensations of thickness and fatty afterfeel. Single and multiple bite results are discussed in terms of possible peripheral mechanisms. Switching results are discussed in terms of possible central sensory contrast mechanisms.

The effect of adding saliva or a saliva-related fluid (α-amylase solution and water) to custard prior to ingestion on the sensory ratings of odour, flavour and lip-tooth-, mouth- and after-feel sensations was investigated. Saliva had previously been collected from the subjects and each subject received his/her own saliva. Sixteen subjects from a trained panel assessed 17 flavour and texture attributes of soy- and milk-based custard desserts. Immediately prior to administration, two different volumes (0.25 and 0.5 ml) of three different saliva-related fluids (saliva, α-amylase solution and water) were added to the product. The added volumes represented an approximately 33% and 66% increase of the volume of saliva present in the mouth during ingestion. The results show that addition of a fluid affected the mouth-feel attributes of melting, thickness and creamy. Melting was the only attribute on which the type of fluid had an effect, where saliva elicited a stronger melting effect than the α-amylase solution and water. The volume of the added fluid affected a number of attributes (thick and creamy mouth-feel and fatty after-feel). It can be concluded that in general the sensory attributes of semisolids were relatively stable. Mouth- and after-feel sensations were partly affected, while odour, flavour and lip-tooth-feel sensations were not affected by an increase in volume of saliva or other saliva-related fluid during ingestion. © 2003 Elsevier Science Inc. All rights reserved.