There are three distinct objectives in reducing the post-prandial blood glucose peaks: 1st to reduce the risk of foetal macrosomia in pregnancy, 2nd to reduce cardiovascular morbi-mortality, 3rd to lower the HbA1c. With 6-7 glycaemic controls per day and fractionning their meals, motivated women with gestational diabetes reach this goal. But there is no data today directly proving that post-prandial glycaemia is specifically related to the development of micro and macrovascular complications. So to reduce the cardiovascular risk, there are more arguments in favour of lowering HbA1c or prescribing statins than in prescribing a hypoglycaemic drug acting selectively on post-prandial glycaemia. Lastly, to reduce HbA1c near to the goal of 7%, the most important is to reduce the preprandial glycaemia below 1.20 g/l. The patients must be required to monitor their post-prandial glycaemia 2 hours after the beginning of the meal only when the aim is to lower the HbA1c below 7% or 6.5%, for example during pregnancy, or in case of discrepancy between glycaemia at 8 a.m. and 7 p.m. (below 1.20 g/)l and HbA1c (above 7%). In other cases, in type 2 diabetes, two glycaemias per day, fasting and vesperal, seems sufficient.