Combining psychology and nutrition?

Hi,
I'm currently finishing my BA in English and Aesthetics and I'm planning to do a MSc conversion into Psychology.
Anyway, I'm interested in both psychology and nutrition quite equally and I'd love to combine it. After graduating in Psychology I'd do a degree/certificate in Nutrition. My ideal kind of job would be a nutritional psychologist but so far this seems to be an American thing only.
When I looked at the teams of people working in various health centers and eating disorders clinics, they all seemed to be either professional psychologists or professional nutritionists/dietitians.

Anyone having the same interests and struggling which one to choose?