AbstractGuar gum, obtained from the seeds of Cyamopsis tetragonolobus (L.) Taub. (Leguminosae), and carob gum, obtained from the seeds ofCeratonia siliquaL. (Leguminosae), were investigated for their effect on body weight, blood glucose and insulin levels in rats fed on a diet containing 15% of guar or carob gums for 2 to 6 consecutive weeks. At the same time, cholesterol plasma levels were assayed. A decrease in both plasma glucose and IRI levels together with a decreased haematic cholesterol level were observed.