Should a diabetic avoid root vegetables and onion?

Q: I have some doubts regarding diabetes. My husband is diabetic and some doctor in India advised him not to take root vegetables and onion as these are very dangerous for a diabetic. I would like to know how far is this true?

A:There is no harm in taking onions. Root vegetables have higher starch content and therefore not favoured. However,it is not necessary to totally stop them.