Meal Volume Research Articles

An alternative method of blood-feeding Culicoides imicola and other haematophagous Culicoides species for vector competence studies

The use of cotton wool pads saturated with blood/virus mixture for oral infection attempts was compared to membrane feeding for the assessment of vector competence in C. imicola Kieffer and C. bolitinos Meiswinkel (Diptera, Ceratopogonidae). Although lower infection rates were obtained using pad feeding, it was possible to clearly distinguish the levels of competence between species as well as differences in virus infection rates for various serotypes of bluetongue virus. Reduced infection rates with cotton pad feeding was partly due to a smaller volume of blood meals taken up. However, the method described is likely to be useful in situations where membrane feeding is not viable to separate populations with significant differences in vector competence.

Gastric Fullness, Physical Activity, and Proximal Extent of Gastroesophageal Reflux

Proximal extent of gastroesophageal reflux (PER) is relevant for symptoms in GERD patients. It has been suggested that PER is determined by the volume of the refluxate that, in turn, might depend on the degree of gastric fullness. Abdominal straining, during ambulation, increases the likelihood of gastroesophageal reflux. We assessed the influence of gastric fullness and ambulation on proximal extent of reflux. PER was assessed in 37 patients with GERD undergoing ambulatory pH impedance monitoring. In 14 controls and 19 GERD patients, esophageal pH impedance and gastric emptying were also studied simultaneously in stationary conditions. We compared PER during fasting, early postprandial (before half emptying), and late postprandial periods in ambulatory and stationary conditions. More reflux episodes reached the proximal esophagus in the postprandial period compared to fasting (60%+/-4 vs 29%+/-3, p<0.05). In stationary conditions, early postprandial reflux reached higher proximal extent than late postprandial reflux (15+/-3% vs 8+/-4%, p<0.05). The proportion of reflux events reaching the proximal esophagus was significantly higher in ambulatory than in stationary conditions (29+/-5% vs 15+/-3%, p<0.05). Compared to fasting, reflux episodes occurring after the meals are more likely to reach higher proximal extent, particularly so during the early postprandial period. The highest proportion of postprandial proximal reflux occurred in ambulatory condition. These findings suggest that reducing meal volumes and early postprandial physical activity might contribute to decrease proximal extent of reflux and postprandial GERD symptoms.

Effects of drink volume and glucose load on gastric emptying and postprandial blood pressure in healthy older subjects

Postprandial hypotension (PPH) occurs frequently in the elderly; the magnitude of the fall in blood pressure (BP) is related to the rate of glucose entry into the duodenum during intraduodenal glucose infusion and spontaneous gastric emptying (GE). It is unclear if glucose concentration affects the hypotensive response. Gastric distension may attenuate PPH; therefore, meal volume could influence the BP response. We aimed to determine the effects of 1) drink volume, 2) glucose concentration, and 3) glucose content on the BP and heart rate (HR) responses to oral glucose. Ten subjects (73.9 +/- 1.2 yr) had measurements of BP, GE, and blood glucose on 4 days after 1) 25 g glucose in 200 ml (12.5%), 2) 75 g glucose in 200 ml (37.5%), 3) 25 g glucose in 600 ml (4%), and 4) 75 g glucose in 600 ml (12.5%). GE, BP, HR, and blood glucose were measured for 180 min. After all drinks, duodenal glucose loads were similar in the first 60 min. Regardless of concentration, 600-ml (but not 200-ml) drinks initially increased BP, and in the first 30 min, systolic BP correlated (P < 0.01) with volume in both the proximal and total stomach. At the same concentration (12.5%), systolic BP fell more (P = 0.02) at the smaller volume; at the same volumes, there were no effects of concentration on BP. There was no difference in the glycemic response to drinks of identical glucose content. We conclude that 1) ingestion of glucose at a higher volume attenuates and 2) under constant duodenal load, glucose concentration (4-37%) does not affect the fall in BP.

Magnetic resonance imaging to investigate the influence of posture on gastric physiology

Magnetic resonance imaging to investigate the influence of posture on gastric physiology

Loss of Meal-Induced Decrease in Plasma Ghrelin Levels in Patients with Anorexia Nervosa

Studies have shown that ghrelin plays a major role in energy homeostasis and modulation of feeding behavior. However, little is known about the influence of food consumption on plasma ghrelin levels in humans. Therefore, we investigated responses of plasma ghrelin to food intake, meal volume and meal nutritional value in healthy volunteers and women with anorexia nervosa (AN). After overnight fasting, all subjects received either a standardized breakfast or fiber. Plasma ghrelin levels were measured before and after the meal. Fasting plasma ghrelin was significantly higher in AN patients than in controls (1,800.6 +/- 47.0 vs. 795.9 +/- 24.3 pg/ml, P < 0.001) (606.8 +/- 15.8 vs. 268.2 +/- 8.2 pmol/l, P < 0.001), and correlated negatively with percentage of body fat in both groups. Ghrelin levels markedly fell after consumption of either a standardized meal or fiber in controls, but not in anorexic women. Thus, we concluded that the acute plasma ghrelin response to food intake, which in healthy individuals is independent of meal caloric value, is impaired in women with AN. This abnormality may be part of a chronic adaptation to prolonged food restriction, which attempts to restore a normal feeding conduct by maintaining the drive to eat.

Effect of gastric electrical stimulation (GES) on satiety and meal volume in patients with gastroparesis

Effect of gastric electrical stimulation (GES) on satiety and meal volume in patients with gastroparesis

料理選択型栄養教育をふまえた一食単位の食事構成力形成に関する研究―「弁当箱ダイエット法」による食事の適量把握に関する介入プログラムとその評価―

Meal planning skills that are easily practiced in a daily life tend to be strongly needed in view of the prevention and treatment of life-style related diseases to cater for the wide variety of the life styles, health problems, meals and cooking methods, and food information. The “Lunch Box Diet Method, ” which is based on the framework of the Dish-Selecting Method of nutritional education, has been theoretically and practically proved to be effective for understanding one meal volume, and an intervention (educational) program to understand the appropriate volume of one meal was created, which has included one study meeting, we asked 49 mid- and high-age female learners as subjects to participate in this program for a practice period of 1 to 3 weeks, during which they could practice the method freely according to their own schedule. The learners practiced the “Lunch Box Diet Method” for an average of 9.4±6.7 days in their daily life. The volume of meals during the practice period became more appropriate than that before the study meeting, and their weight, percentage of body fat and blood quality have significantly improved. Their dietary knowledge, attitude and behavior have also significantly improved. 96% of the learners encouraged their family, friends and neighbors to test the “Lunch Box Diet Method.”These results indicate that the program is easily usable in daily life and is effective for producing meals and improving health.

Dietary Habits of Smokers and Non-smokers in the Korean Health and Nutrition Survey

Differences in dietary habits between Korean smokers and non-smokers were investigated using information obtained from 7,370 adults, aged 20 years and older who participated in the 1998 Korean National Health and Nutrition Survey. Dietary habit data including: skipping of meals, meal regularity, meal volume, snacking habits, removing fatty portions before eating foods, and dietary supplement intake were collected using a structured questionnaire by interview. Individual smoking data was also collected by interview as part of the health behavior survey. A Chi-square test was used to test the association between the dietary habits and smoking. 66.9% of the men were smokers (daily current or occasional current), while only 6.7% of women smoked. On average, 34.7% of the subjects were smokers. Smokers were more likely than nonsmokers to engage in the following dietary habits considered unhealthy: skipping breakfast, meal irregularity, large dinners, small breakfasts, frequently eating out, and eating food without removing the fatty portion. Therefore, Korean smokers should be provided education to assist them in making healthy dietary choices such as: eating regular meals, small dinners, and removing fatty portion of foods. The survey also revealed that a substantial percentage (about 20%) of the subjects were taking some kind of dietary supplement, regardless of smoking status. It is, therefore, also necessary to inform the general public that a balanced diet is the ideal way to obtain nutrients for optimal health.

On-line, simultaneous quantification of ethanol, some metabolites and water vapour in breath following the ingestion of alcohol

Selected ion flow tube mass spectrometry, SIFT-MS, has been used to measure simultaneously the concentrations in exhaled breath of ethanol, acetaldehyde, ammonia, acetone and, routinely, water vapour, following the ingestion of various amounts of ethanol in 500 ml of water. These breath analyses were obtained from only single exhalations, the results being available immediately in real time. The breath ethanol reaches concentrations that are only approximately consistent with its dilution in blood and body water. For moderate ethanol doses the decay quickly exhibits first-order kinetics (a single exponential decay) whereas for relatively large ethanol doses, the initial decay of ethanol from the breath is slow, indicating saturation kinetics. For smaller doses, and following a meal, the breath ethanol increases only slightly indicating that it is largely metabolized in the stomach. We suggest that the time delay (following ethanol ingestion) before the breath ethanol begins to increase is an indicator of the gastric emptying rate. Then the rate of decay of ethanol from the breath/blood is related to its rate of metabolism subsequent to its dispersal into the body water. The much lower breath acetaldehyde levels correlate well with the ethanol levels indicating that it is mostly formed from the metabolism of the ethanol. The breath ammonia is seen to ‘dip’ following the water/alcohol drink and this is consistent with previous work in which this same phenomenon was observed following the ingestion of comparable volumes of liquid meals. The simultaneous breath acetone concentrations increase somewhat with time as is expected during the fasting state. The water vapour measurements are indicators of the precision and accuracy of the breath analyses, these being sufficient to show the differences between the breath (body) temperatures of the individuals of less than 1 °C. This study demonstrates the potential of SIFT-MS for non-invasive physiological measurement.

Effects of gender, body mass index and age on maximum tolerated volume and postprandial symptoms of a liquid meal in healthy volunteers

Effects of gender, body mass index and age on maximum tolerated volume and postprandial symptoms of a liquid meal in healthy volunteers

Effect of intermittent high-intensity exercise on gastric emptying in man.

The effect on gastric emptying of brief intermittent high-intensity sprints and a moderate-intensity steady-state cycle exercise was studied. Eight healthy male subjects were each studied at rest (R), during steady-state exercise at a constant power output corresponding to 66% of their VO(2max) (C66), during intermittent high-intensity exercise at a power output averaging 66% of their VO(2max) (I66), and during intermittent high-intensity exercise at a power output averaging 75% of their VO(2max) (I75). Gastric emptying was measured using the double-sampling gastric aspiration technique. Subjects ingested 600 mL of a 6% carbohydrate-electrolyte solution immediately before exercise or seated rest. The volume of test solution in the stomach was less at all time points on trial I66 than on trial I75 (P = 0.023). The rate of gastric emptying, expressed as the median (range) time (minutes) taken to empty half the test meal volume (t(1/2)), was not different on trials R (20 (7--30)) and C66 (21 (7--49)), and was faster than on trial I75 (62 (27--100); P = 0.003 and P = 0.005, respectively). Median t(1/2) was faster on trial R than on trial I66 (30 (15--74) min; P = 0.019), but no difference was detected between C66 and I66 or between I66 and I75. However, over the initial 30 min period after ingestion, the median (range) volume of test drink delivered to the duodenum was faster (P < 0.01) on trials R (387 (296--541) mL) and C66 (389 (165--584) mL) than on trials I66 (331 (191--494) mL) or I75 (249 (79-335) mL). The data demonstrate that gastric emptying of liquids is slowed during brief intermittent high-intensity exercise compared with rest or steady-state moderate exercise.

Influence of gender on proximal gastric motor and sensory function

OBJECTIVE: Gender-related differences have been demonstrated with regard to GI motility: gallbladder contraction, colonic transit, and gastric emptying are delayed in women. It is not known whether gender influences proximal gastric motility and perception. METHODS: We have studied the influence of gender on proximal gastric motility and perception under fasting and postprandial conditions by retrospective analysis of data obtained in 99 healthy volunteers (42 men, 57 women) who participated in barostat studies performed according to standardized protocols at the Leiden University Medical Center (Leiden, The Netherlands) between 1996 and 2000. RESULTS: Minimal distending pressure (MDP) was significantly higher in women than in men (respectively, 6.8 ± 0.2 vs 5.5 ± 0.2 mm Hg; p < 0.001). During stepwise pressure distensions pressure-volume curves were similar in both sexes after correction for MDP, whereas perception of fullness and abdominal pressure increased significantly ( p < 0.05) more rapidly in women. Before the meal intragastric volumes (at MDP + 2 mm Hg) did not differ between sexes. After the meal gastric relaxation in the first 30 min did not differ in women and men (respectively, 186 ± 23 ml and 140 ± 32 ml). However, from 30 until 90 min after the meal a significantly ( p < 0.05) delayed return of intragastric volume to basal was seen in women. Perception of postprandial nausea was significantly ( p < 0.01) increased in women. Perception of postprandial fullness remained increased for a longer period of time in women. CONCLUSIONS: Proximal gastric motility and perception are influenced by gender. Gender-related differences in postprandial proximal gastric motility and perception should be taken into account in barostat studies comparing patients with controls.

Influence of gender on proximal gastric motor and sensory function.

Gender-related differences have been demonstrated with regard to GI motility: gallbladder contraction, colonic transit, and gastric emptying are delayed in women. It is not known whether gender influences proximal gastric motility and perception. We have studied the influence of gender on proximal gastric motility and perception under fasting and postprandial conditions by retrospective analysis of data obtained in 99 healthy volunteers (42 men, 57 women) who participated in barostat studies performed according to standardized protocols at the Leiden University Medical Center (Leiden, The Netherlands) between 1996 and 2000. Minimal distending pressure (MDP) was significantly higher in women than in men (respectively, 6.8+/-0.2 vs 5.5+/-0.2 mm Hg; p < 0.001). During stepwise pressure distensions pressure-volume curves were similar in both sexes after correction for MDP, whereas perception of fullness and abdominal pressure increased significantly (p < 0.05) more rapidly in women. Before the meal intragastric volumes (at MDP + 2 mm Hg) did not differ between sexes. After the meal gastric relaxation in the first 30 min did not differ in women and men (respectively, 186+/-23 ml and 140+/-32 ml). However, from 30 until 90 min after the meal a significantly (p < 0.05) delayed return of intragastric volume to basal was seen in women. Perception of postprandial nausea was significantly (p < 0.01) increased in women. Perception of postprandial fullness remained increased for a longer period of time in women. Proximal gastric motility and perception are influenced by gender. Gender-related differences in postprandial proximal gastric motility and perception should be taken into account in barostat studies comparing patients with controls.

Reproductive physiology of Aedes (Aedimorphus) vexans (Diptera: Culicidae) in relation to flight potential.

Total protein, lipid, and glycogen of Aedes vexans (Meigen) were related linearly to body size at eclosion. Starvation after emergence led to the determination of minimal irreducible amounts of protein, lipid, and glycogen and the availability of the teneral reserves, whereas access to sucrose revealed the potential for reserve synthesis. Glycogenesis and lipogenesis increased reserves approximately 10-fold the teneral value within 1 and 2 wk after emergence, respectively. Carbohydrate feeding was an essential behavior before blood feeding and oogenesis commenced. Female flight was tested on a flight mill. Maximal flights of 10-17 km in a single night occurred at 2 wk posteclosion and paralleled maximal reserve syntheses. Comparisons of our laboratory data to host-seeking mosquitoes in the field confirmed our data. The vast majority of maternal lipid was transferred to the yolk when a blood meal was taken, but only a quarter of the blood protein was recovered from mature ovaries. Maternal glycogen was used mainly for flight. Fecundity varied between 20 and 120 eggs per female and was determined largely by body size and blood meal volume. At 27 degrees C maximal egg numbers were produced, but at 22 and 17 degrees C the caloric yolk content was greater. Females from the southern United States were smaller than females from northern areas. However, southern females had similar fecundity as northern females, and their flight performances were similar. Differences in the reproductive physiology between this species and Ae. aegypti were discussed.

Effect of intragastric volume and osmolality on mechanisms of gastroesophageal reflux in children with gastroesophageal reflux disease

Both transient lower esophageal sphincter (LES) relaxations (TLESRs) and periods of low/absent LES pressure (LESP) are the main mechanisms of gastroesophageal reflux. These events are believed to be triggered by stimuli from different areas of the upper GI tract. We aimed at investigating the relationship between LESP profile and gastric emptying and distension after meals of different composition in 30 children with gastroesophageal reflux disease (median age 7.0 yr, range 12 months-12 yr). Recordings of LESP and intraesophageal pH for 1 h fasting and for 2 postprandial h were performed with a perfused sleeve catheter and flexible electrode, respectively; gastric emptying and distension of antral area were simultaneously recorded with real-time ultrasonography. Ten patients had a standard meal (group A), 10 had a high-volume meal (group B), and 10 had a high-volume and osmolality meal (group C). Postprandial esophageal acid exposure was significantly higher in patients of groups B and C than in patients of group A (p < 0.01); it was also more prolonged in patients of group C than in subjects of group B (p < 0.05). A higher postfeeding rate of reflux episodes caused by TLESRs was detected in patients of groups B and C as compared with patients of group A (p < 0.01). This increase did not statistically differ in patients of groups B and C. Patients of group C exhibited a higher postprandial rate of reflux episodes associated with low/absent tone of the LES as well as a more prolonged gastric emptying time and a higher postfeeding gastric distension as compared with patients of groups A and B (p < 0.01). Finally, a significant correlation was only found between the postprandial rate of reflux events resulting from low/absent LESP and the degree of antral distension in patients of group C (p < 0.01). Gastroesophageal reflux is worsened by increasing the volume and osmolality of meals through significant changes of LESP. Meals of high volume and meals with high volume and osmolality cause a comparable increase of reflux episodes as a result of TLESRs. However, meals with high volume and osmolality cause the higher degrees of esophageal acid exposure than meals with high volume resulting from a higher rate of reflux episodes associated with low/absent LESP. This finding correlates with a high postfeeding antral distension.

Effect of intragastric volume and osmolality on mechanisms of gastroesophageal reflux in children with gastroesophageal reflux disease

OBJECTIVE: Both transient lower esophageal sphincter (LES) relaxations (TLESRs) and periods of low/absent LES pressure (LESP) are the main mechanisms of gastroesophageal reflux. These events are believed to be triggered by stimuli from different areas of the upper GI tract. We aimed at investigating the relationship between LESP profile and gastric emptying and distension after meals of different composition in 30 children with gastroesophageal reflux disease (median age 7.0 yr, range 12 months–12 yr). METHODS: Recordings of LESP and intraesophageal pH for 1 h fasting and for 2 postprandial h were performed with a perfused sleeve catheter and flexible electrode, respectively; gastric emptying and distension of antral area were simultaneously recorded with real-time ultrasonography. Ten patients had a standard meal (group A), 10 had a high-volume meal (group B), and 10 had a high-volume and osmolality meal (group C). RESULTS: Postprandial esophageal acid exposure was significantly higher in patients of groups B and C than in patients of group A ( p < 0.01); it was also more prolonged in patients of group C than in subjects of group B ( p < 0.05). A higher postfeeding rate of reflux episodes caused by TLESRs was detected in patients of groups B and C as compared with patients of group A ( p < 0.01). This increase did not statistically differ in patients of groups B and C. Patients of group C exhibited a higher postprandial rate of reflux episodes associated with low/absent tone of the LES as well as a more prolonged gastric emptying time and a higher postfeeding gastric distension as compared with patients of groups A and B ( p < 0.01). Finally, a significant correlation was only found between the postprandial rate of reflux events resulting from low/absent LESP and the degree of antral distension in patients of group C ( p < 0.01). CONCLUSION: Gastroesophageal reflux is worsened by increasing the volume and osmolality of meals through significant changes of LESP. Meals of high volume and meals with high volume and osmolality cause a comparable increase of reflux episodes as a result of TLESRs. However, meals with high volume and osmolality cause the higher degrees of esophageal acid exposure than meals with high volume resulting from a higher rate of reflux episodes associated with low/absent LESP. This finding correlates with a high postfeeding antral distension.

Satiation in humans is modulated by fatty acid chain length

Background/Aims The role of cholecystokinin (CCK) in satiety and gastric accommodation is unclear. Whilst exogenous CCK induces satiation in humans, a similar role for endogenous CCK has not been established. Paradoxically, exogenous CCK also relaxes the stomach, which should increase meal volume tolerated. Recent work has shown that intragastric infusion of dodecanoic acid (C12) induces the release of CCK in humans but isocaloric decanoic acid (C10) does not (McLaughlin 1999 Gastroenterology 116:46). We therefore aimed to determine whether 1) intragastric C12 and C10 have differential effects on satiation to an intragastric water load, and 2) any differential effect is paralleled by changes in gastric tone. Methods Vehicle (0.251 PBS and 1.5% v/v Tween 80) alone or with 0.1M C10 or C12 were infused in randomized order into the stomach of 15 healthy volunteers (4 females; mean age 34, range 22-55) following an overnight fast. Subjects were blinded to the nature of the infusion. 20 rains later, water was infused into the stomach at O.21/min to maximum volume tolerated. Plasma CCK concentrations were determined by RIA pre and 15 rains post fatty acid infusion. In 5 of the subjects, the effect of intragastric vehicle, C10 or C12 on proximal gastric tone was studied during distension of a bag sited in the fundus. Data are mean -+ SEM. Water intake was compared using 1-way repeated measures ANOVA followed by Student-NewmanKeuls post hoc test. Paired data were compared by Student t-test. Results C12 induced a rise in plasma CCK (mean plasma CCK concentration pre-C12:3.3 _+ 0.6 pM; post-C12:10,3 +_ 1.4 pM; p<O.05), whilst C10 did not (pre-ClO: 4.6 _+ 2.4pM; post C10:5.5 -+ 0.9pM; p = 0.8). Subjects tolerated significantly more water following vehicle (1636 -+ 178ml) than C10 (1346 -+ 163ml; P<O.05 vs vehicle) and following C10 than C12 (867 -+ 112ml; p<O.05 vs C10), Vehicle alone did not influence proximal gastric tone. C10 and C12 caused a similar reduction in tone (mean reduction following C10:2 -+ 0.47 mmHg; following C12:2 -+ 0.53 mmHg). Conclusions 1) Fatty acid reduces tolerance to water infusion, but also decreases gastric tone. 2) Water tolerance is lower after C12 (which releases CCK) than C10 (which does not). 3) Fatty acids trigger satiation through both CCK-dependent and CCK-indepandent pathways.

Food-conditioned odour rejection in the late stages of the meal, mediating learnt control of meal volume by aftereffects of food consumption

In a two-bottle choice test, rats drank more of the fluid having a novel odour than that having an odour which had previously been presented in the later part of meals on concentrated maltodextrin solution. Rats are normally more averse to a novel odour than to a familiar odour; therefore, the conditioned reaction to the odour acquired in these circumstances is likely to be an ingestive aversion, rather than merely a lack of preference. Furthermore, this learnt odour rejection was seen only in the second half of the meal, indicating that it is dependent on an ingestion-induced state of repletion. Together then, these observations are evidence that the volume of meals rich in carbohydrate can be controlled by learnt rejection of particular food flavours in the presence of visceral cues specific to repletion (previously dubbed “conditioned satiety”), the only known mechanism by which aftereffects of ingested energy could reduce meal volume.

Effects of meal volume on gastric myoelectrical activity and postprandial symptoms in functional dyspepsia

Effects of meal volume on gastric myoelectrical activity and postprandial symptoms in functional dyspepsia

Effect of the energy density and volume of high carbohydrate meals on short term satiety in preschool children.

To investigate the effect of energy density and food volume intakes in one meal (lunch-time) on food and energy intakes in the subsequent meal (tea-time). During lunch, two meals with different energy densities (1.26 and 0.69 kcal/g) were offered to preschool children using normal foods and maintaining a similar energy, carbohydrate, and fat intakes. In the subsequent meal a varied type of high acceptability foods were served in higher amounts than those that children usually consume. A day care center where the children were fed during lunch-time and tea-time. Two hundred and thirty-four normal preschool children, 108 males and 126 females, according to the weight for height index using the NCHS standards. Chemical analysis of the meals served using the AOAC methods and determination of food and energy intakes by differential weighing of the foods. The preschool children had a similar energy intake at lunch but a significantly higher food intake when they consumed the meal with the lower energy density (313 vs. 290.7 kcal) (P = 0.001). There were no differences in the food intakes at the subsequent meal times. The results of this present work demonstrate that under the conditions of the study, there is an inverse relationship between the energy density of the meals consumed at the first meal-time and the energy intakes at the subsequent meal in normal preschool children; and a direct relationship with the short-term satiety. It is possible that differences in satiety reflect, in part, effects from the characteristics of the normal food used in the dietary treatments. These conclusions suggest that future research must be carried out in order to investigate the separate effects of food and the dietary variables commonly used in the studies of food and energy regulations in humans.