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Meal Timing (meal + timing)

Distribution by Scientific Domains
Medical Sciences75%

Selected Abstracts

Daily Meal Timing is Not Necessary for Resetting the Main Circadian Clock by Calorie Restriction

JOURNAL OF NEUROENDOCRINOLOGY, Issue 2 2008
J. Mendoza
In rodents, entrainment and/or resetting by feeding of the central circadian clock, the suprachiasmatic nucleus (SCN), is more efficient when food cues arise from a timed calorie restriction. Because timed calorie restriction is associated with a single meal each day at the same time, its resetting properties on the SCN possibly depend on a combination of meal time-giving cues and hypocaloric conditions per se. To exclude any effect of daily meal timing in resetting by calorie restriction, the present study employed a model of ultradian feeding schedules, divided into six meals with different durations of food access (6 × 8-min versus 6 × 12-min meal schedule) every 4 h over the 24-h cycle. The effects of such an ultradian calorie restriction were evaluated on the rhythms of wheel-running activity (WRA) and body temperature (Tb) in rats. The results indicate that daily/circadian rhythms of WRA and Tb were shifted by a hypocaloric feeding distributed in six ultradian short meals (i.e. 6 × 8-min meal schedule), showing both phase advances and delays. The magnitude of phase shifts was positively correlated with body weight loss and level of day-time behavioural activity. By contrast, rats fed daily with six ultradian meals long enough (i.e. 6 × 12-min meal schedule) to prevent body weight loss, showed only small, if any, phase shifts in WRA and Tb rhythms. The results obtained reveal the potency of calorie restriction to reset the SCN clock without synchronisation to daily meal timing, highlighting functional links between metabolism, calorie restriction and the circadian timing system. [source]

Premixed insulin treatment for type 2 diabetes: analogue or human?

DIABETES OBESITY & METABOLISM, Issue 5 2007
Alan J. Garber
The progressive nature of type 2 diabetes makes insulin initiation a necessary therapeutic step for many patients. Premixed insulin formulations containing both basal and prandial insulin (so called biphasic insulin) are often prescribed because they are superior to long- or intermediate-acting insulin in obtaining good metabolic control. In addition, they are considered as an attractive alternative to classical basal-bolus therapy as fewer daily injections are required. Premixed insulin formulations include conventional (e.g. biphasic human insulin 70/30, or 30/70 in European countries, BHI 30) and newer premixed human analogues (e.g. biphasic insulin aspart 70/30, or 30/70 in Europe, BIAsp 30; insulin lispro mix 75/25,Mix 75/25, or Mix 25/75 in Europe). Like conventional premixed human insulin, premixed insulin analogues contain a fixed proportion of soluble, rapid-acting insulin analogue, with protaminated analogue comprising the remainder. Unlike conventional premixes, analogue premixes have more physiological pharmacokinetic and therapeutically more desirable pharmacodynamic profiles than premixed human insulin. Consequently, postprandial glycaemic control is better with premixed insulin analogues than with premixed human insulin. In nontreat-to-target registration trials, the lowering of haemoglobin A1c with premixed insulin analogues was not inferior to that seen with premixed human insulin. Minor hypoglycaemia was similar for premixed analogue and premixed human insulins, while major hypoglycaemia appears to be rare with either formulation. The occurrence of adverse events, other than hypoglycaemia, was also similar between various premix insulins. The premixed insulin analogues, BIAsp 30 and Mix 75/25, like the fast-acting analogues from which they are derived, also allow flexible injection timing, relative to meal timing, thus improving adherence, compliance and quality of life compared with premixed human insulin. Overall, the evidence suggests that premixed insulin analogues are cost effective and have useful advantages over premixed human insulin for the treatment of type 2 diabetes. [source]

Daily Meal Timing is Not Necessary for Resetting the Main Circadian Clock by Calorie Restriction

JOURNAL OF NEUROENDOCRINOLOGY, Issue 2 2008
J. Mendoza
In rodents, entrainment and/or resetting by feeding of the central circadian clock, the suprachiasmatic nucleus (SCN), is more efficient when food cues arise from a timed calorie restriction. Because timed calorie restriction is associated with a single meal each day at the same time, its resetting properties on the SCN possibly depend on a combination of meal time-giving cues and hypocaloric conditions per se. To exclude any effect of daily meal timing in resetting by calorie restriction, the present study employed a model of ultradian feeding schedules, divided into six meals with different durations of food access (6 × 8-min versus 6 × 12-min meal schedule) every 4 h over the 24-h cycle. The effects of such an ultradian calorie restriction were evaluated on the rhythms of wheel-running activity (WRA) and body temperature (Tb) in rats. The results indicate that daily/circadian rhythms of WRA and Tb were shifted by a hypocaloric feeding distributed in six ultradian short meals (i.e. 6 × 8-min meal schedule), showing both phase advances and delays. The magnitude of phase shifts was positively correlated with body weight loss and level of day-time behavioural activity. By contrast, rats fed daily with six ultradian meals long enough (i.e. 6 × 12-min meal schedule) to prevent body weight loss, showed only small, if any, phase shifts in WRA and Tb rhythms. The results obtained reveal the potency of calorie restriction to reset the SCN clock without synchronisation to daily meal timing, highlighting functional links between metabolism, calorie restriction and the circadian timing system. [source]

Model predictive control with learning-type set-point: Application to artificial pancreatic ,-cell

AICHE JOURNAL, Issue 6 2010
Youqing Wang
Abstract A novel combination of model predictive control (MPC) and iterative learning control (ILC), referred to learning-type MPC (L-MPC), is proposed for closed-loop control in an artificial pancreatic ,-cell. The main motivation for L-MPC is the repetitive nature of glucose-meal-insulin dynamics over a 24-h period. L-MPC learns from an individual's lifestyle, inducing the control performance to improve from day to day. The proposed method is first tested on the Adult Average subject presented in the UVa/Padova diabetes simulator. After 20 days, the blood glucose concentrations can be kept within 68,145 mg/dl when the meals are repetitive. L-MPC can produce superior control performance compared with that achieved under MPC. In addition, L-MPC is robust to random variations in meal sizes within ±75% of the nominal value or meal timings within ±60 min. Furthermore, the robustness of L-MPC to subject variability is validated on Adults 1,10 in the UVa/Padova simulator. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source]