Wikipedia:
In many countries, a person can claim to be a nutritionist even without any training, education, or professional license, in contrast to a dietitian, who has a university degree, professional license, and certification for professional practice.
Not sure why they called her a “nutritionist” in the title. They used the more important job title within the article:
Registered dietitian and nutritionist Emily Field encourages her clients to think about that word before a meal, rather than labeling certain foods "bad" or "good."
To do this, she encourages people to think about three components of a food — fat, carbohydrates, and proteins. Protein fuels your muscles and keeps you feeling full, carbohydrates provide energy, and fat helps us absorb vitamins and minerals while keeping cells healthy. Keeping those nutrients roughly even means you'll have fewer cravings, less desire to binge, and more control when you do eat, Field told Business Insider. So if a meal has a good balance of those three things, it's an okay choice.