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Results for “meal timing”

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At least 19 recordsLinked to original sources
PubMed1991

Meal-time intranasal insulin delivery in type 2 diabetes.

Correction of the deficiency of early meal-time insulin secretion, using intravenous insulin in patients with Type 2 diabetes causes substantial improvement in post-prandial hyperglycaemia. The present study was designed to determine whether similar benefit would result from physiological supplementation using intranasal insulin delivery. Six patients with Type 2 diabetes were studied twice during a standard mixed meal. At the start of the meal they received a single intranasal spray containing either 15 units of insulin in 1% sodium glycocholate (adjuvant agent) or glycocholate alone (placebo) in a single-blind fashion. Intranasal insulin delivery resulted in rapid absorption of insulin with peak levels (92 +/- 8 (+/- SE) mU l-1) within 5-10 min. Peak insulin levels were at least equal to those in non-diabetic subjects, though occurring at an earlier time-point. However, no significant improvement in post-prandial hyperglycaemia was seen (peak blood glucose increment 4.9 +/- 0.6 vs 5.4 +/- 0.5 mmol l-1; total 3-h response 611 +/- 53 vs 668 +/- 41 mmol l-1 min). We conclude that an elevation of insulin levels, earlier and more transient than the normal physiological response, achieved by intranasal insulin delivery at the start of a meal, fails to significantly improve the blood glucose excursion in Type 2 diabetes.

Administration, Intranasal↗
PubMed2025

O-GlcNAcylation of nuclear proteins in the mouse liver exhibit daily oscillations that are influenced by meal timing.

The liver circadian clock and hepatic transcriptome are highly responsive to metabolic signals generated from feeding-fasting rhythm. Previous studies have identified a number of nutrient-sensitive signaling pathways that could interpret metabolic input to regulate rhythmic hepatic biology. Here, we investigated the role of O-GlcNAcylation, a nutrient-sensitive post-translational modification (PTM) in mediating metabolic regulation of rhythmic biology in the liver. We observe daily oscillation of global nuclear protein O-GlcNAcylation in the liver of mice subjected to night-restricted feeding (NRF) using label-free global O-GlcNAc proteomics. Additional site-specific O-GlcNAc analysis by tandem mass tag mass spectrometry further supports temporal differences in O-GlcNAcylation by revealing day-night differences. Proteins involved in gene expression are enriched among rhythmically O-GlcNAcylated proteins, suggesting rhythmic O-GlcNAcylation may directly regulate the hepatic transcriptome. We show that rhythmic O-GlcNAcylation can also indirectly modulate nuclear proteins by interacting with phosphorylation. Several proteins harboring O-GlcNAcylation-phosphorylation interplay motif exhibit rhythmic O-GlcNAcylation and phosphorylation. Specifically, we show that O-GlcNAcylation occurs at a phospho-degron of a key circadian transcriptional activator, circadian locomotor output cycles kaput (CLOCK), thus regulating its stability and transcriptional output. Finally, we report that day-restricted feeding (DRF) in the nocturnal mouse significantly alters O-GlcNAcylation pattern. Whereas global O-GlcNAcylation analysis indicates dampening of global O-GlcNAcylation rhythm in mice fed under DRF, site-specific analysis reveals differential responses of O-GlcNAc sites when timing of food intake is altered. Notably, a substantial number of O-GlcNAcylation sites exhibit inverted day-night profiles when mice are subjected to DRF. This suggests the dysregulation of daily nuclear protein O-GlcNAcylation rhythm may contribute to the disruption in liver transcriptome previously observed in DRF condition. In summary, our results provide new mechanistic insights into metabolic regulation of hepatic transcriptional regulators via interplay between O-GlcNAcylation and phosphorylation and shed light on the deleterious effects of improper mealtimes.

Animals↗
PubMed1975

Meal timing dominates the lighting regimen as a synchronizer of the eosinophil rhythm in mice.

Mouse eosinophils undergo circadian fluctuation, and the phasing of the rhythm normally is synchronized to the environmental light-dark cycle if food always is available. This study was undertaken to determine whether or not the same rhythm could be synchronized to restricted feeding schedules. It was found that if food is available ad libitum for only short spans (in this case, 4 h during each 24 h period), the rhythm becomes synchronized to the feeding schedule. In addition, restricting food to certain 4 h spans causes the amplitude of the eosinophil rhythm to increase significantly over that of normal, light-dark synchronized animals. Not all rhythmic variables synchronize to restricted feeding schedules. Some remain synchronized to the light-dark cycle; the phasing of others seems to be the result of an interaction between both the light-dark cycle and the feeding schedule. These studies help dispel the popular misconception that all body functions react in the same manner to different synchronizers and emphasize that one must not generalize about the synchronizing effect of feeding or lighting.

Animals↗
PubMed2026

Maternal Chrono-Nutrition and Placental DNA Methylation: The BiSC Study.

The impact of diet during pregnancy on birth outcomes and child health is well established, and epigenetic changes may be one mechanism underlying such associations, but the role of meal timing (chrono-nutrition) is unclear. We conducted an epigenome-wide association study (EWAS) of maternal meal timing and placental DNAm (plaDNAm). Data came from 389 pregnant women in the Barcelona Life Study Cohort (BiSC). Chrono-nutrition and dietary data were collected at 20 weeks of pregnancy, and plaDNAm at delivery was characterized using the Illumina EPIC array. Linear robust regression models tested associations between five chrono-nutritional behaviors (time of first and last meal, nighttime fasting duration, number of eating occasions, and eating jetlag) and plaDNAm. We identified 7 CpGs significantly associated with time of last meal (Bonferroni p < 1E-08) and 63 suggestive CpGs (p < 1E-05). Hits included cg13147785 (E2F8), linked to placental cell cycle regulation, cg17665505 (DAP) and cg18303215 (ABCG5), associated with smoking and lung diseases in adults. To conclude, maternal chrono-nutrition was associated with some CpGs in the placenta, particularly time of last meal. Further studies are needed to clarify how meal timing may influence fetal development and long-term health through epigenetic mechanisms.

Humans↗
PubMed1977

Grocery purchases as a function of obesity and assumed food deprivation.

Six hundred and four grocery shoppers were observed unobtrusively at three supermarkets to investigate the relationship between grocery purchasing and the factors of obesity, assumed food deprivation, social class, and meal hour. It has been suggested that shoppers will purchase more if they shop prior to eating rather than after (Stuart & Davis, 1972), although such a notion conflicts with Schachter's (1971) internal-external hypothesis and with the conclusions of one field study (Nisbett & Kanouse, 1969). We found that female shoppers who shopped prior to standard meal times consistently purchased more than those who shopped after meal times (P less than 0.001), regardless of social class or meal hour. Males displayed the same tendency though differences were not significant. No obese-normal differences were found for either sex. A negative relationship between obesity and social class was found amoung females (P less than 0.001).

Adult↗
PubMed1977

Effects of the scheduling of meal-feeding at different phases of the circadian system in rats.

This study was designed to determine whether or not a number of diverse rhythmic variables in the rat could be synchronized to meal timing. This was tested by restricting the availability of food; once during each 24-hour period an unrestricted quantity of food was made available for a 4-hour period to four different groups at different phases of the light-dark cycle, and the rhythms of the variables studied in the different groups were compared. Liver glycogen and serum glucose did synchronize to or were strongly influenced by feeding schedules; corticosterone and the several enzymes measured seemed to reflect an interaction of both the restricted feeding schedule and the light-dark cycle. The mitotic index in the corneal epithelium in all groups remained remarkably synchronized to the light-dark cycle and was altered only minimally by restricted meal timing. All groups on restricted feeding schedules gained less weight than the group fed ad libitum and maintained on a light-dark cycle. These studies caution against assuming that all body functions react in the same manner to different synchronizers; and they emphasize that one must not generalize about the synchronizing effect of meal-timing or even the light-dark cycle.

Animals↗
PubMed1991

Effects of cottonseed meal supplementation time on ruminal fermentation and forage intake by Holstein steers fed fescue hay.

Four ruminally cannulated Holstein steers (average BW 303 kg) were used in a 4 x 4 Latin square design digestion trial to study the influence of daily cottonseed meal (CSM; 1.6 g of CP/kg of BW) supplementation time on forage intake and ruminal fluid kinetics and fermentation. Steers were housed individually in tie stalls and were fed chopped fescue hay on an ad libitum basis at 0600 and 1400. Treatments were 1) control, grass hay only (CON) and grass hay and CSM fed once daily at 2) 0600 (EAM) 3) 1000 (MAM), or 4) 1400 (PM). Ruminal NH3 N concentrations reflected a time of supplementation x sampling time interaction (P less than .05); CON steers had the lowest (P less than .05) ruminal NH3 N concentrations at all times other than at 0600, 1000, 1200, and 2400, when they did not differ (P greater than .05) from at least one of the supplemented groups. Forage intake, ratio of bacterial purine:N, rate of DM and NDF disappearance, and ruminal fluid kinetics were not influenced (P greater than .05) by supplementation time. Total ruminal VFA differed (P less than .05) between CON and supplemented steers, as well as among supplemented steers (linear and quadratic effects P less than .05). Acetate, propionate, and valerate proportions were influenced (P less than .05) by a sampling time X supplementation time interaction. Under the conditions of this study, greater peak ammonia concentrations with morning supplementation than with afternoon supplementation did not stimulate ruminal fermentation or rate of NDF disappearance.

Ammonia↗
PubMed1992

Interaction of liquid aluminium phosphate and aluminium hydroxide with the gastric acid profile. Influence of food components and timing of meals.

AlPO4 is generally perceived as a particularly weak antacid. Its neutralizing capacity, when evaluated with the classical Fordtran test at the pH 3 standard, is several times smaller than that of Al(OH)3, which is considered a particularly potent antacid. This difference of in vitro reactivity of the two antacids is largely due to the fact that the pKa value is considerably lower for AlPO4 than for Al(OH)3. The object of this study was to evaluate in vivo and in vitro the impact of the pKa value of these antacids on their efficacy at low pH values and the modulation of their neutralizing capacity through proteins. Since both preparations display a much closer antacid activity at pH 2, we felt it appropriate to reevaluate the comparative in vivo neutralizing capacity of the two antacids at doses matched with their in vitro reactivity at pH 2. In vivo antacid effects were measured by ambulant pH-metry in 18 healthy volunteers after randomized ingestion of carbohydrate or protein meals. Antacid or placebo medication was given 1 and 3 h after meals. At pH 3.0, the standard milieu of the Fordtran test, preparation A, composed of Al(OH)3 and a small fraction of Mg(OH)2, displayed in vitro a neutralizing capacity of 4.4 mmol/ml, whereas this was 0.18 mmol/ml for preparation B, composed solely of AlPO4 (p less than 0.001). When tested at pH 1, 1.5, and 2, however, the ratio between A and B was below 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Postprandial gallbladder emptying is related to intestinal motility at the time of meal ingestion.

The characteristics of meal-induced gallbladder emptying in healthy individuals are subject to wide variation. We hypothesized that some of the observed variation might relate to ingestion of the meal during different phases of the migrating motor complex (MMC). Recording of gastrointestinal pressure was combined with scintigraphic recording of bile kinetics during infusion of 99mTc-HIDA. The material consisted of 12 healthy men. Group 1 (n = 6) had a fat-rich meal in phase I, and group 2 (n = 6) had the meal in a phase II. With the end of the meal ingestion as zero, the following results emerged. The subjects in group 1 had a median (range) lag period before beginning of gallbladder emptying of 13.5 (9.0-22.5) min. In group 2 gallbladder emptying began during the meal ingestion in four subjects, and the median lag period was 0 min (minimum, -9.0; maximum, 13.5 (p = 0.02)). The median percentage change of gallbladder counts during the observation period of 54 min in group 1 was 11.5% (from 19% filling to 25% emptying). The corresponding figures in group 2 were 41% (from 2% to 91% emptying (p less than 0.05)). This difference was due to the difference in duration of lag periods, as the emptying rates measured from the end of the lag periods were equal. In conclusion, the onset of postprandial gallbladder emptying relates to the phase activity of the MMC at the time of ingestion.

Adult↗
PubMed1979

The effect of maternal posture, meals and time of day on fetal movements.

During the last 3 to 4 months of their pregnancies, six healthy mothers provided a daily record of their own activity together with the amount of fetal movement. Fetal movement increased throughout most of the daytime to reach a peak in the evening. The mothers detected most movement when they were lying, less when they were sitting and least when they were standing. Later in the day the mothers were less likely to be standing and more likely to be sitting; when fetal movement was measured with the mother in the sitting posture, more movement occurred as the day progressed. Mealtimes did not have any effect upon movement. Some implications of these findings, both for the assessment of fetal well-being and for theories of the development of circadian rhythms in the infant, are discussed.

Adult↗
PubMed1992

Interrelationship between sugar and dental caries--a study in child population of Orissa.

An epidemiological study on interrelationship between dental caries and sugar consumption conducted on 1265 children in the age of 5-15 years revealed a positive association of dental caries experience with total sugar exposures, between meal sugar exposures and at meal sugar exposures. As the total increased from 3 to 4 in a day, a corresponding jump of 1 deft+DMFT and 2 defs+DMFS was noted, which was clinically and statistically significant. It was deduced that total sugar exposures per day should be limited to 3, out of which two should be at meal time and one between meals.

Adolescent↗