I have a 7 year old German Shepherd and she seems very healthy but she has lost weight
And she is not putting it back on. Can anyone please help me.
Mike.

Shepherds often don't have much excess weight to lose. Unless there have been some other changes in her life, likely she has a medical problem. I wouldn't risk delaying a vet visit to tempt her with rich food. That is nearly always the wrong thing to do. For more on this see the sticky at https://www.askmehelpdesk.com/dogs/information-articles-our-dogs-expert-labman-53153.html#post254171

Even if this is a rare case of needing more tempting food, I would trust your vet in selecting what.