In the UK, there is no requirement for any formal certification for an individual to address themselves as a 'Nutritionalist'.
Any person who has just a smattering of knowledge; or a lifetime of dieting and a clever spreadsheet can advertise and charge hard cash for 'nutrition' advice.
Therefore, if you require any help or advice on cycling 'nutrition', please do not hesitate to PM "Jimbo the Nutritionalist".
Very reasonable rates.