Is keeping constant weight part of homeostasis?

Yes if its healthy. Maintaining an ideal body weight is critical for health. When we have too much fat, our body becomes inefficient. The nih just showed that in an obese person, 100cal is not 100cal but probably more b/c the body just stops functioning well. Hormonal disruption can occur, inflammation starts and starts this negative spiral downwards towards disease. Maintain a healthy weight & stop many diseases.