The effect of meal frequency on serum immunoglobulins profile, insulin and weight in rat

Abstract

Although consumption of three or less than three meals a day (gorging regimen) is usual in some communities, in western population there is an inclination towards many small meals a day (nibbling regimen). Up to now the effects of meal frequency on serum immunoglobulins have not been investigated in laboratory animals. There is also some controversy information about the effect of meal frequency on serum insulin and weight in human and animal studies. Therefore, the aim of current study is to investigate, for the first time the effects of meal frequency on immunoglobulins profile in rat. The effect of meal frequency on serum insulin and weight in rat are also surveyed. Thirty female Wistar rats aged 11 weeks (210 آ±15 g), after 10 days of acclimation period, were weighed and randomly assigned into two equal groups. They were fed the same food as eight meals at 2-hours intervals starting from 6 p.m. (nibbling group) or as two meals at 9 p.m. and 6 a.m. (gorging group) for 60 days. Blood samples were taken before and after intervention. During the study period, the animals were weighed at the first and every 12 days. ELLISA method was used to the measurement of insulin and the same method was designed for the assay of immunoglobulins in serum. All values were expressed as Meanآ±SD using Student's t-test based comparisons. The research project was reviewed and approved by the Medical Ethics Committee of Tabriz University of Medical Sciences (IRAN). Diet regimens caused a non-significant reduction (P>0.05) in the serum insulin and IgA levels after sixty days of intervention. Although, in the two regimens serum insulin level was non-significantly decreased but the percentage of decreasing in nibbling regimen was more than gorging one (-5.3% vs-2.3%). Serum IgM and IgG levels in the two regimens were significantly increased (P<0.05) but there was no-significant difference (P>0.05) between the two regimens before and after the intervention. Although, in both groups, serum IgM and IgG levels were significantly increased but the percentage of increasing was more in nibbling regimen than gorging one (56% vs 38% and 37% vs 28.7% for IgM & IgG, respectively). The body weight in the two groups of animals was significantly increased (P<0.001). The food and water intakes were non-significantly (P>0.05) lowered in the gorging group compared with the nibbling one. According to the obtained results, there is not a significant difference between nibbling and gorging dietary regimens with respect to serum IgM, IgG, IgA, insulin and weight in rat. é Asian Network for Scientific Information, 2005.