What about nutrition interests you?
Would you rather work in a clinical setting, research or even both?
If you prefer working in a clinical setting, I suggest you enroll in a dietetic intership program. Many universities offer this option as a masters degree (MS or MPH) along with the professional degree as a registered dietian (RD). Afterwards, you need to be licensed in the state where you wish to practice (LD). The MS or MPH will give you some research experience as well.
If you interested in solely research, I suggest getting a PhD in nutritional sciences.