Does anyone of you know whether there’s any opportunity to get an online certification to become a nutritionist/diestist? Any course? Any certification recognized internationaly?
I doubt you’ll find anything recognised in all countries. Most western countries require a university degree for Nutritionists or Dietitians in order for them to be registered or work with national health services or accept insurance. Many countries require a masters degree in order to work in hospitals.
If you just want to call yourself a nutritionist most countries don’t regulate that at all. You could just say you are one. Lots of people do that. That’s why this sub has so much misinformation in it.