INFLUENCE OF MEAL FREQUENCY ON IRON-ABSORPTION AS ASSESSED BY HEMOGLOBIN REPLETION IN RATS

The effects of short periods of fasting, characteristic of a human eat ing pattern consisting of one, two, or four meals daily, on iron absor ption were investigated in anemic rats by hemoglobin repletion assay. Sixty weanling rats were fed a low-iron diet (8 mg Fe/kg diet) for 13 days. The anemic rats were then fed ferrous sulfate- or ferric phospha te-fortified diets (35 mg Fe/kg diet) for 11 days under three feeding regimens: one, two, or four meals daily. Hemoglobin regeneration effic iency (hemoglobin iron gain/Fe intake) was the indicator of iron absor ption. Greater hemoglobin regeneration efficiency was found in rats fe d a FeSO4 diet with four (82.5 +/- 4.8%) or two (78.8 +/- 4.1%) meals daily than those pair-fed one (63.4 +/- 3.4%) meal daily. No significa nt difference among the groups fed one, two, or four meals of the FePO 4 diet was observed. Both iron source and meal frequency significantly affected iron absorption-but the interaction effect was not significa nt. We conclude under the conditions of this study that periods of fas ting as long as 24 hours in the context of a diet do not enhance iron absorption and that feeding patterns are a factor to consider in iron bioavailability determinations. (C) 1997 Elsevier Science Inc.