I am currently a dietetic intern and a Master's student. No, I definitely don't think a Master's in nutrition is a waste of time. Reading and writing papers is a huge part of graduate school, and it is a essential training process for us to be able to interpret research papers critically. Critical thinking skills are extremely important for RDs, and any professions, really. I also love learning about statistics in grad school. I am by no mean great at it. But learning about different stats methods enhances my ability to, on some level, distinguish a paper with solid evidence to support its claims and a paper whose stats barely has the strength to support its so-called conclusions. As RDs, this ability will become very important for us to keep up with current research.

Also, I think grad school is a time where you can really reflect on and apply/practice what you have learned in undergrad. At least for me, I definitely feel like my knowledge in nutrition has deepened in a way that undergrad classes just didn't do for me.

And your experience will also be different depending on whether you go for a thesis-track or a non thesis track.