Associations between spontaneous meal initiations and blood glucose dynamics in overweight men in negative energy balance

The aim of the present study was to investigate associations between spontaneous meal initiations and blood glucose dynamics in overweight male subjects in negative energy balance. In a randomized crossover design, fifteen overweight male subjects (BMI 28.6 (SD 1.8 kg/m2) participated in three treatments, each of which consisted of 2 weeks consuming a low-energy diet followed by a test of voluntary food ingestion in the absence of time-related cues. The low-energy diet consisted of three daily meals (947 kJ) which were either semi-solid with or without 2.5 g guar gum, or solid, and a dinner of subject's own choice. During the time-blinded test, on the first, second, and third meal initiation subjects ingested a low-energy meal corresponding to that used during the preceding weeks. Changes in blood glucose were monitored on-line. Associations between spontaneous meal initiations and blood glucose dynamics were determined using the chi2 test. No difference was found between treatments in the occurrence of postabsorptive and postprandial declines in blood glucose or in associations between meal initiations and blood glucose dynamics. Postprandial dynamic blood glucose declines were associated with meal initiation (chi2 26 8, P<0.00 1), but postabsorptive and postprandial transient declines were not. In overweight subjects, the usual association between transient declines and spontaneous meal initiation was completely absent in negative energy balance

Measurement of the Lambda^0_b lifetime in the decay Lambda^0_b -> J/psi Lambda^0 with the D0 Detector

We present measurements of the Lambda^0_b lifetime in the exclusive decay channel Lambda^0_{b}->J/psi Lambda^0, with J/psi to mu+ mu- and Lambda^0 to p pi-, the B^0 lifetime in the decay B^0 -> J/psi K^0_S with J/psi to mu+ mu- and K^0_S to pi+ pi-, and the ratio of these lifetimes. The analysis is based on approximately 250 pb^{-1} of data recorded with the D0 detector in pp(bar) collisions at sqrt{s}=1.96 TeV. The Lambda^0_b lifetime is determined to be tau(Lambda^0_b) = 1.22 +0.22/-0.18 (stat) +/- 0.04 (syst) ps, the B^0 lifetime tau(B^0) = 1.40 +0.11/-0.10 (stat) +/- 0.03 (syst) ps, and the ratio tau(Lambda^0_b)/tau(B^0) = 0.87 +0.17/-0.14 (stat) +/- 0.03 (syst). In contrast with previous measurements using semileptonic decays, this is the first determination of the Lambda^0_b lifetime based on a fully reconstructed decay channel.Comment: 7 pages, 4 figures, Submitted to Physical Review Letters, v2: Added FNAL Pub-numbe

Measurement of the WW production cross section in p anti-p collisions at s**(1/2) = 1.96 TeV

We present a measurement of the W boson pair-production cross section in p anti-p collisions at a center-of-mass energy of sqrt{s}=1.96 TeV. The data, collected with the Run II DO detector, correspond to an integrated luminosity of 224-252 pb^-1 depending on the final state (ee, emu or mumu). We observe 25 candidates with a background expectation of 8.1+/-0.6(stat)+/-0.6(syst)+/-0.5(lum) events. The probability for an upward fluctuation of the background to produce the observed signal is 2.3x10^-7, equivalent to 5.2 standard deviations.The measurement yields a cross section of 13.8+4.3/-3.8(stat)+1.2/-0.9(syst)+/-0.9(lum) pb, in agreement with predictions from the standard model.Comment: submitted to PR

Habitual meal frequency and energy intake regulation in partially temporally isolated men

Department of Human Biology, University of Maastricht, Maastricht, The Netherlands. [email protected] OBJECTIVE: Assessment of a possible relationship between habitual as well as manipulated meal frequency, blood glucose pattern, macronutrient- and energy intake (EI), and energy intake regulation in partially temporally isolated men. DESIGN: A partially temporally isolated within-subject design assessing energy intake regulation in spite of intervention. Intervention consisted of manipulating meal frequency by offering iso-energetic (1 MJ) preloads high in fat or carbohydrate (CHO), with the same energy density. We have previously shown that after a high-CHO preload, inter-meal-interval was 1 h, while after a high-fat preload intermeal-interval was 2 h. SUBJECTS: Twenty healthy young (18-31 y) normal weight (body mass index (BMI): 22.8+/-1.9 kg/m(2)) men. MEASUREMENTS: On two separate days, each after a different preload: subsequent subjects' responses to the preload, eg manipulated meal frequency; continuous blood glucose levels and blood glucose patterns: macronutrient composition of food intake; EI; appetite ratings; and taste perception. From controlled 3-day food intake diaries: habitual meal frequency; EI; and macronutrient-intake. RESULTS: Accuracy of energy intake regulation is expressed as minimizing the difference in energy intake, despite intervention. The difference in 24 h EI on the two test days after the preloads (r(2)=0.56; P<0.001) was a function of habitual meal frequency. Variation in energy intake was primarily explained by habitual meal frequency (r(2)=0.76; P<0.0001). Adding macronutrient composition and number of blood glucose declines to this increased the explained variation to 86 and 96%, respectively. Percentage energy from CHO or from fat explained the variation in habitual meal frequency (r(2)=0.84; P<0.0001). Adding the total number of blood-glucose declines to this increased the explained variation to 88%, and adding average baseline blood glucose levels, sweetness perception and hunger suppression during preload consumption increased the explained variation to 91%. Manipulated meal frequency was related to habitual meal frequency (r(2)=0.86; P<0.0001) and was a function of the number of transient and dynamic blood glucose declines (r(2)=0.74; P<0.0001). CONCLUSION: Habitual meal frequency is of greater significance in energy intake regulation in healthy young men than manipulated meal frequency. Healthy young men with a high habitual meal frequency showed lower 24 h EI, and a smaller difference in EI after macronutrient specific preloads, compared to those with a low habitual meal frequency, thus showing a more accurate energy intake regulation. Habitual meal frequency is based upon a cluster of related factors including macronutrient composition of the food, sweetness perception, hunger suppression, blood glucose declines and average baseline blood glucose levels. Publication Types: Clinical Trial Randomized Controlled Tria

Blood glucose patterns and appetite in time-blinded humans: carbohydrate versus fat.

Department of Human Biology, Maastricht University, 6200 MD Maastricht, The Netherlands. We assessed the extent to which a possible synchronization between transient blood glucose declines and spontaneous meal initiation would lend support to the interpretation of a preload study with isoenergetic (1 MJ) isovolumetric high-fat or simple carbohydrate (CHO) preload drinks. Ten men (18-30 yr) fasted overnight and then were time blinded and made aware that they could request meals anytime. At first meal requests, volunteers consumed a preload; ad libitum meals were offered at subsequent requests. Postabsorptively, transient declines in blood glucose were associated with meal requests (chi(2) = 8.29). Subsequent meal requests occurred during "dynamic declines" in blood glucose after the peak induced by drink consumption (100%). These meal requests took twice as long to occur after high-fat than after CHO preloads (fat = 126 +/- 21, CHO = 65 +/- 15 min), consistent with differences in interpolated 65-min satiety scores (fat = 38 +/- 8.2, CHO = 16 +/- 4). Postprandially, transient blood glucose declines were associated with meal requests (chi(2) = 4.30). Spontaneous meal initiations were synchronized with transient and dynamic blood glucose declines. Synchronization of intermeal interval and dynamic declines related to higher satiating efficiency from high-fat preloads than from simple CHO preloads. Publication Types: Clinical Trial Randomized Controlled Tria

The effect of guar gum addition to a semisolid meal on appetite related to blood glucose, in dieting men

OBJECTIVE: To investigate whether addition of modified guar gum (GG) to a low-energy semisolid meal might be effective on appetite by modifying the response of blood glucose and other blood parameters. DESIGN: Three intervention periods of 2 weeks each, separated by washout periods of 4 weeks. Randomized and cross-over design. SUBJECTS: Fifteen overweight male subjects (mean+/-s.d.; age, 44+/-9 y; body mass index, 28.6+/-1.8 kg/m(2)). INTERVENTION: Subjects consumed a low-energy diet divided over three times a day, consisting of a semisolid meal with (SSM+) or without (SSM) addition of 2.5 g GG, or a solid meal (SM) with the same energy content (947 kJ) and macronutrient composition, plus a dinner of the subject's own choice. At the end of each intervention, time and number of meal initiations, dynamics of blood glucose and other blood parameters, and appetite ratings such as hunger and satiety were determined in a time-blinded situation. RESULTS: The changes in blood glucose from meal initiation to blood glucose peak and from peak to nadir were smaller with SSM+ and SM compared to SSM. Satiety before the third meal was higher with SSM+ and SM compared to SSM (P<0.01). Meal pattern, general appetite and total energy intake were similar for all treatments. CONCLUSIONS: We conclude that, similar to SM, SSM+ resulted in a more moderate change in blood glucose compared to SSM and positively affected satiety before the third meal, while general appetite, total energy intake and meal pattern did not differ