In keeping with the excellent advice found in the footnote on page 161 of Ben Goldacre's book Bad Science, I shall henceforth refer to myself as a nutritionist.
I sense that some qualifications may be in order.
To be clear, I'm not going to start doling out any complicated medical advice: nothing more complex than "eat your greens" or "avoid excessive consumption of intoxicants", at any rate. While I am qualified to provide guidance on how to train a neural network, set up cross-validation for a time-series predictor, or replicate go-to functionality with a for-loop, I am in no way qualified to provide medical or dietary advice. Much like, I dare say, most nutritionists.
But that's what this is all about, isn't it? I recall with amusement (and some trepidation, don't mistake me!) the recent attempt to allow exemptions to the Texas Higher Education Coordinating Board's requirements for postsecondary educational institutions, so that the Institute for Creation Research could start handing out graduate degrees. If that's allowed, suddenly a Master's degree from Texas is meaningless; much like a degree from a nutritionist college.
Again, let's be clear: I don't think that "nutrition" is bunk. I don't think that the study of nutrition is bunk. In fact, I am engaged to be married to an intelligent and lovely graduate of the Human Nutritional Sciences program at the University of Manitoba (who also happens to be a nominal Lutheran; more on that later, I'm sure). But before she can be classified as a dietician (note the terminology, here), she must undergo a one-year professional internship (between forty-two and fifty-two weeks of unpaid, full-time work in clinics, hospitals, and community programs). The difference between a dietitian and a nutritionist, in training and in professional practices, seems to me something like the difference between a medical doctor and a doctor of homeopathy.
So please, join me in calling yourself a nutritionist. It is an unregulated word, and we have as much a right to it as the pill-pushing quacks do.