Food Feeding Problems.

Hi, My 16 months baby is not eating anything, she is not picky eater but almost completely stopped eating Food..I am tired of trying different methods to feed her Food, still not successful. Please help! She must be 10 kg & above, but now she is only 8 kg. Her Growth has also become slow! I took her to doctor last week, Doctor says everything is normal but she looks weak & everybody is commenting on her slow growth & under development.