A.P.
My two-year old has the same problem. He refuses to eat anything but carbs and often ands up with a really nasty case of constipation. We usually get him Bolthouse Farms "Green Goodness". It is in the produce section at Target and most other grocery stores. It is one of those "yummy" looking smoothies. My little boy will refuse to eat or drink a lot of things, but he likes his "poop juice". The other thing you might try, just to get here going is getting some Mil of Magnesia and putting a teaspoon in with the juice. Good luck!