This is a very subjective question
There are so many factors that go into this such as how overweight is your client to begin with?
As we all know many people lose “a lot ” of weight initially but then reality comes into play
Looking at your profile I don’t see that you are a registered dietitian or have a degree in nutrition?
As personal trainers, it is not within our scope of practice to give out “diet plans” or specific nutritional advice.
If you do have the proper qualifications it would be great to see them.