Experimental protocol phase 1 Each child will arrive at the UOC at 8 a.m., in fasting since 9 p.m. the previous evening. A blood sample will be taken with a needle cannula on the antecubital vein. Then patients will be given two LibramedR tablets or placebo. After another 20 minutes they will be given a mixed meal to be consumed within 20 minutes. Blood samples will then be taken at 30-minute intervals for the first two hours and 60 minutes for the following two hours, for the determination of metabolites and hormones for a total of 4 hours (baseline + 6 blood samples).