I prefer unflavoured natural yoghurt. Greek yoghurt is a bit too acidic-tasting for first thing in the morning.

Unfortunately, the only non-Greek yoghurt on shop shelves is over-processed flavoured “fat-free” yoghurt-type deserts. Milk is basically Fat and Water, with some solids in suspension. Fat-free milk is just water and some solids. Fat free yoghurt is just water and metabolised solids and tastes terrible. So they add sugar to make it taste and suddenly Fat-free dairy has a higher GI than normal dairy.