Hi Karen,
Parrots are not likely to overeat as long as their nutritional needs are met. The main thing to watch for with Nutri-Berries is that you want him to eat most of each berry without wasting too much. Grey are very smart and will learn if they eat a few bites and toss the rest, they might get more. I make a point of returning any discarded berry pieces to the food bowl as long as it didn’t land in poop. His pellets and Nutri-Berries should be his main diet with the rest making up a small percentage – about 10-20% depending on the nutritional value. As the main diet, without pellets, a Grey will eat anywhere from 6-12 Nutri-Berries daily. Because the amount can vary so much based on the individual, we say give him as many as he can eat each day, without wasting too much. As Dr. Lamb pointed out, we tend to way over feed our birds. So start with a few and then give him more when those are gone. Meanwhile he still has his pellets and other foods.
Thank you for asking Lafeber,
Brenda