BOTH RAW AND RETROGRADED STARCH DECREASE SERUM TRIACYLGLYCEROL CONCENTRATION AND FAT ACCRETION IN THE RAT

Male Wistar rats were meal-fed on diets containing various amounts of resistant starch in the form of raw starch (either amylomaize starch, potato starch or modified high-amylose starch) or retrograded starch ( prepared from each of the starches) for 6 weeks. Two diets containing normal maize starch were fed as diets poor in resistant starch. Energy absorption (energy consumption minus faecal energy loss), growth, wei ght of the epididymal fat pads, serum total cholesterol and triacylgly cerol concentrations and a number of intestinal and faecal variables w ere determined. The resistant starches affected all the variables dete rmined except the serum total cholesterol concentration. Relationships were found between energy absorption and both growth and the weight o f the fat pads, and between the weight of the fat pads and both the se rum triacylglycerol concentration and the serum total cholesterol conc entration. No clear differences between the effects of the two types o f resistant starch (raw starch v. retrograded starch) were found excep t that raw potato starch hardly stimulated H-2 excretion and led to lo wer amounts of propionic and butyric acids in the caecal contents than the other starches. The results suggest that dietary resistant starch reduces energy absorption leading to less abdominal depot fat and low er serum triacylglycerol concentrations.