ABSTRACT
Background
We previously reported that a whole-egg–based diet attenuated weight gain in rats with type 2 diabetes (T2D) and more effectively maintained vitamin D status than an equivalent amount of supplemental cholecalciferol.
Objectives
The objective of this study was to determine the lowest dose of whole egg effective at maintaining vitamin D homeostasis and attenuating the obese phenotype in T2D rats.
Methods
Zucker diabetic fatty (ZDF) rats (n = 40; age 6 wk; prediabetic) and their lean controls (n = 40; age 6 wk) were randomly assigned to a diet containing 20% casein (CAS) or 20%, 10%, 5%, or 2.5% protein from whole egg (20% EGG, 10% EGG, 5% EGG, and 2.5% EGG, respectively). All diets contained 20% total protein (wt:wt). All rats received their respective diets for 8 wk, at a stage of growth and development that translates to adolescence in humans, until 14 wk of age, a point at which ZDF rats exhibit overt T2D. Weight gain was measured 5 d/wk, and circulating 25-hydroxyvitamin D [25(OH)D] was measured by ELISA. Mean values were compared by 2-factor ANOVA.
Results
The 20% EGG diet maintained serum 25(OH)D at 30 nmol/L in ZDF rats, whereas the 10%, 5%, and 2.5% EGG diets did not prevent insufficiency, resulting in mean serum 25(OH)D concentrations of 24 nmol/L in ZDF rats. Body weight gain was reduced by 29% (P < 0.001) and 31% (P < 0.001) in ZDF rats consuming 20% and 10% EGG diets, respectively, and by 16% (P = 0.004) and 12% (P = 0.030) in ZDF rats consuming 5% and 2.5% EGG diets, respectively, compared with CAS.
Conclusions
Whole-egg–based diets exerted a dose-dependent response with respect to attenuating weight gain. These data could support dietary recommendations aimed at body weight management in individuals predisposed to obesity and T2D.
Dietary Whole Egg Consumption Attenuates Body Weight Gain and Is More Effective than Supplemental Cholecalciferol in Maintaining Vitamin D Balance in Type 2 Diabetic Rats
