This was my main worry when I switched from a complete 3 years ago. However, I soon realised that I could judge fairly well how much to give. Just know your dog well and if you think that they are getting a bit thin - give more and if a bit too heavy give less ! Should really be the same as any food - giving the amount shown on the packet for complete can be just as wrong as well

It is always better to keep them a bit on the thin side. I think that there is a formula based on a % of the dog's weight, but I prefer to judge it by 'eye'

My older dog keeps a very steady weight - I weigh him if I have to go to the vets and it changes by very little.
Daisy