Honestly I think one of the easiest ways is to search https://www.precisionnutrition.com/fitness-pros-directory https://www.precisionnutrition.com/fitness-pros-

Honestly I think one of the easiest ways is to search https://www.precisionnutrition.com/fitness-pros-directory https://www.precisionnutrition.com/fitness-pros-directory. You need to pass their nutrition course, which is very good on nutrition. It also costs quite a pretty penny, so if they're willing to spend that on training themselves and have passed it, there is probably a pretty good bet that they're good.