Number Of Chews Research Articles

The Betel Quid Dependence Scale: Replication and extension in a Guamanian sample

BackgroundBetel quid is the fourth most commonly consumed psychoactive substance in the world. The Betel Quid Dependence Scale (BQDS) is the first instrument designed specifically to measure betel quid dependence. The three factor structure of the BQDS consists of “physical and psychological urgent need,” “increasing dose,” and “maladaptive use.” The BQDS initially was validated in a sample of male prisoner ex-chewers in Taiwan. ObjectiveTo replicate and extend the original validation research on the BQDS in a sample of male and female current betel quid chewers in Guam. MethodsA survey containing the BQDS was administered to 300 current betel quid chewers in Guam. Participants were compensated for their time with a gift card worth $25. ResultsConfirmatory factor analysis revealed an adequate fit with the hypothesized three-factor measurement model. ANOVAs and structural equations modeling revealed that betel quid dependence is associated with the inclusion of tobacco in the quid, number of chews per day, years of chewing, and education. ConclusionsThe BQDS is valid for current English-speaking male and female chewers in Guam. Overall levels of betel quid dependence were high, and most chewers included tobacco in their betel quid. The results suggest that levels of dependence for betel quid are similar to those observed for nicotine dependence. Future research should explore other important psychological and behavioral aspects of betel quid chewing such as health risk perceptions and motivation to quit chewing.

Efficacy of a novel training food based on the process model of feeding for mastication and swallowing ― A preliminary study in elderly individuals living at a residential facility ―

Nakagawa K, Matsuo K, Shibata S, Inamoto Y, Ito Y, Abe K, Ishibashi N, Fujii W, Saitoh E. Efficacy of a novel training food based on the process model of feeding for mastication and swallowing ― a preliminary study in elderly individuals living at a residential facility ―. Jpn J Compr Rehabil Sci 2014; 5: 72-78. Purpose: We examined the validity and safety of a newly developed chew-swallow managing food (CSM) as a training material for chewing and swallowing. Methods: Twenty-three elderly individuals (mean age: 82.8 ± 8.6 years) who followed a regular diet at a residential facility were enrolled in this study. The subjects ate 4 g each of CSM and puree 3 times while bolus transport and swallowing were recorded with a fiberoptic endoscope. For each trial, the number of chewing and swallowing movements was counted. We also identified the location of the leading edge of the food at swallow initiation, the amount of food residue in the oral cavity and pharynx, and the incidence of aspiration. The differences in measurements between CSM and puree trials were then compared statistically. Results: With the CSM, the number of chewing and swallowing movements was significantly higher than that with puree and the leading edge of the food was deeper in the pharynx at swallow initiation. There were no significant differences in food residue or aspiration between the 2 foods. Conclusion: Our findings suggest that CSM has an initial consistency that requires chewing but changes to a texture equivalent to puree at the time of swallowing. We are currently planning to verify the safety and efficacy of CSM in individuals with dysphagia.

Correlation between intake and ingestive behavior of pasture-grazed heifers

Objetivou-se com este estudo, avaliar a correlação entre o consumo e comportamento ingestivo de novilhas mestiças em pastagem tropical. O experimento foi conduzido na Fazenda Princesa do Mateiro, na cidade de Ribeirão do Largo, Bahia. Foram utilizadas 20 bezerras com a composição genética de 5/8 de Guzerá Leiteiro e 3/8 de Holandês, idade média de 18 meses e peso corporal de 187 ± 13,1 kg. O experimento durou 224 dias e os animais mantidos em sistema de pastejo rotacionado com Brachiaria brizantha cv. Marandú. O tempo de pastejo não correlacionou com nenhuma das variáveis associadas com a ingestão. O tempo de ruminação mostrou correlações positivas com a ingestão de matéria seca da forragem (CMSF) e fibra em detergente neutro (CFDN). Variáveis associadas ao tempo gasto em alimentação no cocho, alimentação em geral e mastigação total, não foram correlacionados com a ingestão (P>0,05). Houve correlação positiva entre o número de períodos de pastejo (NPP) e os períodos de ruminação (NPR) e consumo de MS total (CMST), matéria orgânica (CMO), forragem ( CMSF), fibra em detergente neutro (CFDN), carboidratos totais (CCHOT), extrato etéreo (CEE). O consumo de proteína bruta (CPB) foi positivamente correlacionado com NPP e NPR. A taxa de bocado foi positivamente correlacionada com CMST, CMO, CMSF, CFDN, CCHOT, CEE e CPB. O tempo médio por bolo ruminado foi negativamente correlacionada com CMST, CMO, CFDN, CHOT e CEE. Correlações positivas foram observadas entre o número de bocados por dia e CMST, CMO, CMSF, CFDN, CHOT e CEE. O número de mastigações por bolo mostraram correlações negativas com CMSS e CPB. O tempo por bolo ruminado foi negativamente correlacionada com a ingestão de proteína bruta. O número de mastigações por bolo mostrou correlações positivas com os consumos de matéria seca e fibra em detergente neutro. O número de bolos por dia mostraram correlações positivas com CMSF e CCHOT. O tempo de mastigação não mostrou correlação significativa com o consumo. Em conflito com a literatura nacional e internacional, o tempo de pastejo não foi correlacionada com a ingestão por novilhas mestiças em pastejo. O número de atividades, o tempo gasto e a taxa de bocado, tem demostrado ser altamente correlacionados com as variáveis de consumo e pode, por conseguinte, compor equações para predizer o consumo a partir da avaliação do comportamento ingestivo. O número de bocados realizados por dia contribui para a ingestão de novilhas em pastagem.

Increasing the Number of Chews before Swallowing Reduces Meal Size in Normal-Weight, Overweight, and Obese Adults

Eating slowly contributes to a lower risk of obesity, probably because it could aid appetite control. Chewing thoroughly is an effective strategy to reduce eating rate; however, insufficient data are available to demonstrate the relationship between such an eating behavior and energy intake. To investigate the effect of increasing the number of chews before swallowing on meal size, a randomized cross-over trial was conducted in 18- to 45-year-old normal-weight, overweight, and obese participants (n=45) who were recruited from the local community (Ames, IA). After assessment of baseline number of chews, participants were asked to attend three test sessions to eat pizza for lunch until comfortably full by chewing each portion of food either 100%, 150%, or 200% of their baseline number of chews before swallowing. Two-way analysis of variance was used to test the effect of treatment and body-weight status, as well as their interactions on food intake, meal duration, eating rate, and appetite at meal termination. Appetite data during 60 minutes were analyzed by repeated measures analysis of variance. Food intake in the sessions with 150% and 200% of their baseline number of chews was reduced significantly, by 9.5% and 14.8%, respectively, compared with the 100% session. Increasing the number of chews also prolonged meal duration and reduced eating rate. However, subjective appetite at meal termination or during the immediate postprandial period did not differ. These data indicate that increasing the number of chews before swallowing might be a behavioral strategy to reduce food intake and potentially aid body-weight management.

Feeding behavior and performance of sheep fed cactus pear in substitution of corn

The objective of this study was to evaluate the feeding behavior and performance of Santa Ines sheep subjected to different levels of substitution of corn by cactus pear in the diet. Forty-fivenon-castrated male Santa Inês sheep with initial live weight of 27.50±0.48 kg were distributed in a completely randomized design with five treatments (0, 70, 140, 210 and 280 g/kg DM) and nine replicates. Dry matter and neutral detergent fiberintakes showed quadratic behavior. Times spent eating, ruminating and total ruminating chews showed increasing linear behavior, while the idle time decreased with increasing amounts of dietary cactus. The feeding efficiency (gDM/h) increased linearly, while differences in rumination efficiency of the DM (g DM/h); NDF intake efficiency (gNDF/h) and NDF rumination efficiency (gNDF/h) were not significant. There was no significant effect for the number of ruminated boli and number of ruminating chews per bolus. The number of chews per day increased linearly. These results indicate that cactus pear in substitution of corn had no influence on the feeding behavior of feedlot sheep.

Chewing thoroughly reduces eating rate and postprandial food palatability but does not influence meal size in older adults

Recent studies have shown that increasing the number of chews before swallowing reduces meal size in young adults. However, whether this ingestive behavior influences meal size in older adults is unknown. Eighteen older adults (4 males and 14 females, age 72±1years, body mass index 25.9±1.2kg/m2) participated in this randomized cross-over trial. A preliminary session was conducted to assess their habitual number of chews (HNC) using pizza rolls as the test food. Participants then attended three test sessions at their habitual lunch time. In each test session, participants were asked to eat pizza rolls until comfortably full, by chewing each pizza roll for 100%, 150% and 200% of HNC before swallowing. Subjective appetite was measured at regular time points for 60min after meal initiation. There was no difference in meal duration and meal induced change in appetite at meal termination between test sessions. However, eating rate at the 150% and 200% of HNC sessions (16.4±1.0g/s and 13.7±0.8g/s, respectively) was significantly reduced, compared with eating rate at the 100% of HNC condition (22.5±1.8g/s). Moreover, thorough chewing significantly reduced postprandial ratings on palatability of the test food. There was no significant difference in food intake between test sessions (177.8±43.0g, 164.0±41.7g, and 166.6±33.0g for 100%, 150% and 200% of HNC, respectively). These results suggest that increasing the number of chews does not affect meal size in older adults. Aging-related appetite dysregulation may partly account for the difference in results from studies in young and older adults.

Bolus Moisture Content of Solid Foods during Mastication

AbstractSaliva addition plays an important role in bolus formation. During chewing, food breaks down, exposing food particles to saliva. The aim of this study was to explore and understand how bolus moisture content changes during the oral processing of solid foods. Twelve subjects chewed commercially produced solid foods; the boluses were collected at different stages of the mastication process, including the swallowing point, and all of the boluses produced were analyzed for their moisture content. The chewing sessions were recorded on video, enabling the number of chews to be assessed for each subject and food type. Results showed that moisture content of boluses during mastication increased linearly at a rate depending on the subject and food types studied. It was found that for the food types studied, an increase in initial food moisture content increased the bolus moisture content at the swallowing point.Practical ApplicationsSensory perception experienced during oral processing of foods is through sensing the bolus properties, which change continuously in between ingestion and swallowing. Understanding changes in bolus moisture content, the role of food structure and effects on sensory perception can help in designing foods with predictable sensory attributes. This study demonstrated that while saliva additions vary between people and food types, they increase linearly during mastication. Changes in bolus moisture content during mastication could be used to guide the design of solid foods with target properties.

Comportamento ingestivo de cordeiros alimentados com torta de macaúba

Avaliaram-se os efeitos de diferentes porcentagens (0, 10, 20 e 30%) de inclusão da torta de macaúba (TM) no comportamento ingestivo de 24 cordeiros Santa Inês, com média de cinco meses de idade e peso vivo de 23,9kg, distribuídos em delineamento em blocos ao acaso, com quatro tratamentos e seis repetições, durante 60 dias de confinamento. Foram avaliados os tempos médios despendidos com alimentação, ruminação (TR), ócio (TO), tempo de mastigação total (TMT), eficiência de alimentação (EA MS e EA FDN) e eficiência de ruminação, além do número de bolos ruminados (NBR) e número diário de mastigações merícicas (MMnd). A adição de TM à dieta aumentou linearmente o TR, TMT, NBR, MMnd e EA FDN e reduziu de forma linear o TO, em consequência do maior teor de fibra em detergente neutro das dietas com o coproduto. Mesmo com o aumento no TMT, não foi verificada diferença no consumo e na eficiência de ruminação e alimentação da matéria seca, possivelmente em razão da baixa efetividade de fibra da TM, demonstrando o potencial de utilização desse coproduto na dieta de ovinos em crescimento.

Automatic recognition and classification of cattle chewing activity by an acoustic monitoring method with a single-axis acceleration sensor

Monitoring the eating habits and rumination of cattle is effective for evaluating forage values and making animal management decisions for stalls and grazing pastures. Acoustic monitoring is a feasible method to monitor these activities, but it requires automatic distinction and quantification of activities to gain broader application. This automatic distinction and quantification may be possible using a pattern matching method, which distinguishes jaw movements by extracting characteristic patterns from eating and ruminating, and then matches similar characteristic patterns in unanalyzed activities. The objectives of this study were to define an acoustic monitoring system with a single-axis acceleration sensor, to determine an effective sensor attachment site (i.e., the horn, forehead, or nasal bridge), and to assess the automatic classification of ingestive and ruminative chewing behaviors using a pattern matching method. Four beef cows fed Italian ryegrass silage were each recorded eating and ruminating for more than 60 and 20min, respectively. The oscillatory waveforms generated while eating and ruminating were clearly recorded by the single-axis acceleration sensor, regardless of sensor attachment site. The pattern matching method correctly distinguished ingestive chewing with an accuracy of over 0.9, regardless of the sensor site (estimated number of chews by automatic detection/true number of chews by manual detection). Placement of the sensor on the horn of the animal resulted in the most matched measurement (0.99). In contrast, the method overestimated ruminating chewing time (approximately 1.50) because noises that occurred during idling were misclassified as ruminating chewing. The provision of an additional chewing criterion for automatic detection, i.e., chewing is performed consecutively (context-based cues), improved the classification accuracy of ruminating to a range of 1.02–1.08. In conclusion, automatic detection using a pattern matching method successfully classified ingestive chewing and ruminating chewing in cattle, and a single-axis acceleration sensor was useful for acoustic monitoring at all sensor attachment sites.

Effect of Stocking Density on Eating Behavior of Finishing Hanwoo Steers (Bos taurus coreanae)

This study was carried out to investigate the effects of stocking density on eating and ruminating behavior of Hanwoo steers (Bos taurus coreanae) in the finishing period. A total of 30 finishing Hanwoo steers (631.3 ± 11.4 kg, 25 months old) were allocated to one of four stocking density groups comprising 1, 2, 3, and 4 steers per 32 m 2 pen [G1 (32 m 2 ), G2 (16 m 2 ), G3 (10.7 m 2 ) and G4 (8 m 2 ), respectively] in triplicate. Eating, rumination behaviors, as well as dry matter intake of steers were measured, and the results were subjected to analysis of variance with stocking density as the main effect. The results of eating behaviors over 48 hours are summarized as follows: Total intake was significantly (p G2 > G3 > G4 (p<0.01). However, resting time and chewing time (sum of eating and ruminating) were not significantly different among the treatments. Number of boluses and number of total chews were highest in G1 (p<0.01), whereas number of chews per bolus was highest in G3 (p<0.01). Ruminating time per bolus as well as number of boluses per minute was not significantly different among the treatments. Number of defecations was higher in G1 and G2 animals compared to G3 and G4 animals (p<0.01). However, stocking density had no effect on drinking or urination. In conclusion, increasing stocking density (i.e. G4) per pen decreased voluntary intake, ruminating time, and total chewing number in the finishing period of Hanwoo steers. However, care must be taken in discussing stocking density in the present study as the space allowance per animal was satisfactory to meet the current animal welfare regulation in Korea and in Europe, although the beef production system in Korea is more intensive than in Europe.

Oral processing characteristics of solid savoury meal components, and relationship with food composition, sensory attributes and expected satiation

Background: The modern food supply is often dominated by a large variety of energy dense, softly textured foods that can be eaten quickly. Previous studies suggest that particular oral processing characteristics such as large bite size and lack of chewing activity contribute to the low satiating efficiency of these foods. To better design meals that promote greater feelings of satiation, we need an accurate picture of the oral processing characteristics of a range of solid food items that could be used to replace softer textures during a normal hot meal. Aim: The primary aim of this study was to establish an accurate picture of the oral processing characteristics of a set of solid savoury meal components. The secondary aim was to determine the associations between oral processing characteristics, food composition, sensory properties, and expected satiation. Methods: In a within subjects design, 15 subjects consumed 50g of 35 different savoury food items over 5 sessions. The 35 foods represented various staples, vegetables and protein rich foods such a meat and fish. Subjects were video-recorded during consumption and measures included observed number of bites, number of chews, number of swallows and derived measures such as chewing rate, eating rate, bite size, and oral exposure time. Subjects rated expected satiation for a standard 200g portion of each food using a 100mm and the sensory differences between foods were quantified using descriptive analysis with a trained sensory panel. Statistical analysis focussed on the oral processing characteristics and associations between nutritional, sensory and expected satiation parameters of each food. Results: Average number of chews for 50g of food varied from 27 for mashed potatoes to 488 for tortilla chips. Oral exposure time was highly correlated with the total number of chews, and varied from 27s for canned tomatoes to 350s for tortilla chips. Chewing rate was relatively constant with an overall average chewing rate of approximately 1chew/s. Differences in oral processing were not correlated with any macronutrients specifically. Expected satiation was positively related to protein and the sensory attributes chewiness and saltiness. Foods that consumed in smaller bites, were chewed more and for longer and expected to impart a higher satiation. Discussion: This study shows a large and reliable variation in oral exposure time, number of required chews before swallowing and expected satiation across a wide variety of foods. We conclude that bite size and oral-sensory exposure time could contribute to higher satiation within a meal for equal calories.

Oral processing characteristics of solid meal components, and relations with food composition, sensory attributes & expected-satiation

The current obesogenic food environment is characterized by energy dense, softly textured foods that can be eaten quickly. Previous studies suggest that oral processing characteristics such as large bite size, low number of chews and low orosensory exposure contribute to the low satiating efficiency of these foods. The current study investigated the oral processing characteristics of 35-solid meal components and examined associations between oral processing characteristics, food composition, sensory properties and expected satiation. A panel of 15 subjects consumed 50 g of 35-foods representing various staples (potatoes, rice, pasta), vegetables (broccoli, carrot), and protein rich foods such as meat and fish. Subjects were video-recorded during consumption of each food and their eating behaviours were coded for the number of bites, chews and swallows and derived measures such as chewing-rate, eating-rate, bite-size, and orosensory residence time. Subjects rated expected fullness for the 35-foods and the sensory differences were quantified using a separate trained sensory panel. Oro-sensory residence time was highly correlated with the number of chews (R2 = 0.98) and chew-rate was relatively constant at approximately 1 chew/s. Expected fullness was positively correlated with energy density (R2 = 0.40), protein (R2 = 0.33) and the sensory attributes chewiness (R2 = 0.15) and saltiness (R2 = 0.12). Foods that were consumed in smaller bites, were chewed for longer and were expected to impart a higher satiation. This information may be used to design foods/meals lower in energy and higher in satiating efficiency per kcal consumed.

Comportamento ingestivo de novilhas suplementadas a pasto sob nutrição compensatória ingestive

O estudo foi realizado com o objetivo de avaliar os efeitos da nutrição compensatória em novilhas suplementadas a pasto sobre o comportamento ingestivo. O experimento foi conduzido na fazenda Princesa do Mateiro, município de Ribeirão do Largo, Bahia. Foram utilizadas 20 novilhas com grau de sangue 5/8 Guzerá Leiteiro 3/8 Holandês, com média de 18 meses de idade e peso corporal médio de 187 ± 13,07 kg. O experimento teve duração de 224 dias e os animais foram mantidos em sistema de produção a pasto, em pastejo rotacionado de Brachiaria brizantha "Marandú". Os animais foram aleatoriamente alocados em cada um dos tratamentos: Controle (T100): Animais recebendo concentrado para suprir 100 % da exigência de nutrientes para ganho de 750 g/dia; Nutrição compensatória (NC): Animais que alternaram o nível de alimentação entre os períodos, sendo que nos períodos de restrição receberam concentrado para suprir 80 % da exigência de nutrientes digestíveis totais do tratamento controle (T80) e nos períodos de realimentação receberam concentrado para suprir 120 % das exigências de nutrientes digestíveis totais do tratamento controle (T120). Nos períodos de restrição, as médias do tempo de pastejo foram maiores para o NC (533 vs. 426 minutos) (p

How do dairy cows chew?—Particle size analysis of selected feeds with different particle length distributions and of respective ingested bolus particles

Not only feed but also respective bolus particle size could alter diet efficiency and cow performance. The objective of this project was to characterize particle size of selected feeds and respective swallowed boli. Feed samples included 6 different particle length rye grass hay samples, 1 grass silage, 1 corn silage, and 1 total mixed ration (TMR). Rye grass hay samples consisted of long hay and chopped hay particles retained on the 19- (19_PSPS hay), 8- (8_PSPS hay), and 1.18-mm (1.18_PSPS hay) Penn State Particle Separator (PSPS) screens and those collected on the pan (PSPS_pan hay). A sixth hay treatment was rye grass forage cut at 50-mm lengths and dried to hay (50-mm hay). Treatments were offered to 4 nonlactating and 4 lactating cows following rumen evacuation. Swallowed boli were collected and the number of chews per gram of ingested feed dry matter was determined. Feed and bolus particles of lengths ≥5mm were collected on a 1.6-mm screen using a horizontal wet sieving technique. This cut point was chosen, as the literature suggests that most fecal particles are shorter than 5mm. Dry matter proportions on this screen (PROP_1.6) were determined and particle lengths of retained particles were measured by image analysis. Mean particle lengths (ML) were calculated considering particles ≥5mm in length. Boli of long hay, of 19_PSPS hay, of 8_PSPS hay, and of 50-mm hay had similar ML of 10 to 11mm. Bolus PROP_1.6 were also similar between these treatments, ranging from 0.54 to 0.69. Bolus particle lengths and distributions of these treatments were not related to respective hay particles. Bolus of 1.18_PSPS hay had PROP_1.6 of 0.51 and a smaller ML of 8mm. The PSPS_pan hay had PROP_1.6 of only 0.33, but was still chewed intensely. Apparently, little particle size reduction occurred when cows ate the TMR or the silages. Feed and respective bolus PROP_1.6 were as follows: 0.66 and 0.59 in grass silage, 0.52 and 0.55 in corn silage, and 0.44 and 0.38 in the TMR. Feed and respective bolus ML were as follows: 13.8 and 11.6mm in grass silage, 12.0 and 11.2mm in corn silage, and 13.1 and 12.5mm in the TMR. Rye grass hay particles retained on PSPS screens ≥8mm, with ML of at least 25mm were longer compared with TMR particles, but respective bolus particles were shorter. Bolus particle size is not associated with the size of large feed particles chewed to a constant size that is appropriate for deglutition. This size may be related to feed chemical composition.

Chewing number is related to incremental increases in body weight from 20 years of age in Japanese middle‐aged adults

Eating habits are associated with both current obesity and incremental increases in body weight from young adulthood, but no study has focused on chewing number during meals among community residents. This study focused on the relationship between chewing number and incremental increases in body weight from 20 years of age. A total of 93 persons aged 35-61 years participated. The subjects were asked to set the device and record their chewing number during each meal on a particular day. They were also asked whether their body weight had increased by 10 kg or more since they were 20 years old. The body weight of 28 subjects (30%) had increased more than 10 kg since the age of 20 years. Total chewing number showed a relationship with such body weight increases. The odds ratio of weight increments of more than 10 kg for the lowest tertile group was 4.6 [95% confidence interval (CI), 1.3-16.2] relative to the highest tertile group (Model 1). The odds ratio of weight increments for the lowest tertile group increased to 6.3 (95% CI, 1.6-25.4) in Model 2 and to 9.1 (95% CI, 1.7-49.8) in Model 3. Although this study was limited because it did not consider all risk factors, categorical chewing number was related independently to body weight increments of more than 10 kg from 20 years of age.

Increasing the number of masticatory cycles reduces food intake in healthy young adults

To investigate if the number of masticatory cycles made during ingestion affects satiation, 47 healthy participants (16 lean, 16 overweight and 15 obese) were recruited for this present study. Pizza rolls were used as the test food and their habitual mastication parameters were measured before they were randomized to a treatment order. Participants were asked to consume the same breakfast and reported to the laboratory for lunch, once a week for three weeks. After baseline appetite measures were made they were asked to eat until they were comfortably full, by chewing each portion of the food at their habitual number of chews, 150% or 200% of their habitual number of chews. Subjective appetite was measured regularly for 60 minutes and upon meal termination. There was no effect of body mass index (BMI) on habitual number of chews, chewing rate and chewing duration. Adjusting for BMI, increased number of masticatory cycles resulted in increased meal duration (P&lt;0.0001) and reduced food intake (P=0.0026). 200% of the habitual number of chews reduced the food intake by 15% (P=0.0007) whereas 150% of the habitual number of chews reduced the food intake by 10% (P=0.0257). The number of chews did not affect hunger, fullness, desire to eat and palatability of the test food. The results suggest increasing the number of chews promotes satiation and could be a strategy for body weight management.Grant Funding Source : Iowa State University

Effect of masticatory cycles on postprandial appetite and subsequent food intake in seniors

Seniors are a population at the increased risk of inadequate food intake. It is not clear how appetite and postprandial metabolism are influenced in this age group by change in the number of masticatory cycles during ingestion. In a randomized cross‐over study, 15 senior males consumed a fixed amount pizza meal, by chewing each portion 15 or 40 times before swallowing. Appetite questionnaires and plasma samples were collected at regular intervals over three hours following meal consumption. An ad libitum meal was provided three hours later and the amount eaten measured. Compared to 15 chews, making 40 chews per portion resulted in lower hunger (P&lt;0.001), lower preoccupation with food (P&lt;0.001) and lower desire to eat (P&lt;0.001). Higher levels of plasma glucose, insulin and gastric inhibitory polypeptide were found immediately following the 40 chews (P&lt;0.05), but they became significantly lower later (P&lt;0.05). No effect on cholecystokinin and ghrelin was found. There was a trend toward significant reduction in food intake at the subsequent meal following the 15 chews condition (P=0.066). The results suggest that increasing the number of chews promotes postprandial satiety in senior males but also paradoxically promotes food intake at the subsequent meal. The impaired control of food intake in seniors and different glycemic responses under different chewing conditions may partly explain for the results.Grant Funding Source: Iowa State University

Self-reports of eating quickly are related to a decreased number of chews until first swallow, total number of chews, and total duration of chewing in young people

ObjectiveThe validity of a self-questionnaire about eating quickly remains unclear. If a significant relationship between subjective and objective methods to evaluate eating quickly can be confirmed, then the subjective method can be widely and reliably used in many fields. This study investigated relationships between subjective and objective methods to evaluate eating quickly and also numerically characterized the kinesis of eating quickly in young people. DesignOne hundred and thirteen students (44 males and 69 females; mean age 22.8±2.0 years) were selected. All subjects completed written questionnaires, and number of chews until first swallow, total duration of chewing, number of chews, chewing rate and bite size were measured using test products (a Japanese cracker and rice ball). ResultsBoth male and female subjects who reported eating quickly showed a significantly lower number of chews until first swallow (Japanese cracker), a lower number of chews overall (rice ball), and a shorter total duration of chewing (rice ball) than other subjects. There was no difference in chewing rate between subjects who ate quickly or not. ConclusionsThese findings suggest that using test products, self-reports of eating quickly are related to a decreased number of chews until first swallow, total number of chews, and total duration of chewing, but not chewing rate, and that a self-reported questionnaire to evaluate eating rate is valid in young people.

Interrelations among physical characteristics, sensory perception and oral processing of protein-based soft-solid structures

Oral processing is essential in breaking down the physicochemical structure of the food and thus important to the sensory perception of food in the mouth. To have an understanding of protein-based, soft-solid texture perception, a multidisciplinary approach was applied that combined studies of food microstructure with mechanical properties, sensory evaluation, and oral physiology. Model foods were developed by combining ion-induced micro-phase separation and protein-polysaccharide phase separation and inversion. Activities of masseter, anterior temporalis and anterior digastric muscles during oral processing were recorded by electromyography (EMG), while jaw movement amplitudes, durations, and velocities were simultaneously collected by a three-dimensional jaw tracking system (JT-3D). Changes in the microstructure of mixed gels significantly altered the characteristics of the chewing sequence, including the muscle activities, number of chews, chewing duration and chewing frequency. Mechanical attributes related to structural breakdown and sensory perception of firmness were highly correlated with the amount of muscle activity required to transform the initial structure into a bolus ready for swallowing. Chewing frequency was linked to mechanical properties such as recoverable energy, fracture strain and water holding capacity of the gels. Increased adhesiveness and moisture release also resulted in slower chewing frequency. Evaluation of oral processing parameters at various stages (i.e., first cycle, first 5 cycles, and last 3 cycles) was found to be a useful method to investigate the dynamic nature of sensory perception at first bite, during chewing and after swallowing. The study showed that muscle activity and jaw movement can be used to understand the links between physical properties of foods and sensory texture.

Intake and feeding behaviour of Morada Nova lambs fed different energy levels

The effects of metabolizable energy levels were evaluated on nutrient intake and ingestive behaviour in Morada Nova lambs. Forty Morada Nova lambs were used with an initial weight of 12.2±2.05 kg. Five treatments were defined according to the metabolizable energy levels (0.96, 1.28, 1.72, 2.18 and 2.62 Mcal/kg DM). The experimental model was a randomized block design. Linear effect (P<0.0001) of ME levels was determined for dry matter intake (DMI), organic matter (OM), crude protein (CP), total carbohydrates (TC), non-fibrous carbohydrates (NFC) and total digestible nutrients (TDN) in g/day. Quadratic effect was determined for NDF (P<0.017) and carbohydrate intake (P<0.003). Linear effect was determined for digestibility of DM, OM, NDF, TC and NFC. Eating, ruminating and total chewing times, expressed in hours/day, decreased linearly (P<0.0001) with the energy levels of experimental diets. Idle time increased linearly (P<0.0001) with the increase of energy levels of the rations. Feeding and rumination efficiencies were influenced by the energy levels (P<0.0001) when expressed in g DM/h. The number of ruminal boluses, number of chews and chews per ruminal bolus were not affected by the levels of ME. However, time spent chewing per ruminal bolus was influenced (P<0.0014). Increase in ME levels of diets influences nutrient intake and feeding behaviour of Morada Nova lambs during the growing period.