You could try a 'breakfast' style drink product - I'm not sure exactly what's available (it's not something I buy) - but I'd expect that there are some things on offer near the breakfast cereals.

A word of warning, though...if you are overweight, they are extremely dense in sugar... so might not be considered 'part of a balanced diet'.

I experience waves of nausea with pregnancy, and at other times, which seem to be hormonal.

For something equivalent to 'complan' I'm quite sure you could ask the apotheke - I assume you've spoken to the doctor ? I've had experience with dieticians in the past and found them extremely helpful with restricted/special diets...