Be sure to avoid the following because they can disturb or even antidote homeopathic treatment:
What about coffee?
Many homeopaths advise patients not to drink coffee during homeopathic treatment. However if one can not stop, then our experience is that unless the patient is particularly sensitive, coffee generally does not interfere with the remedies. Therefore, if it is possible to stop drinking coffee during treatment that would be optimal, but if one can not stop, then it's fine.