From what I’ve gathered, Apetito (cyproheptadine) is a prescription medication used to help increase the appetite in people with medical conditions that cause poor appetite and weight loss. When someone stops taking Apetito after using it consistently, it's normal to experience some weight loss as appetite decreases back to pre-medication levels. This weight loss is not necessarily unhealthy in my opinion, but does reflect a return to one's natural appetite.

It's therefore important to work closely with one's doctor to gradually taper/titrate your Apetito dosage accordingly, if discontinuing, to allow the body to adjust and prevent extreme weight fluctuations or elevated cortisol levels (stress hormones) all of which can impact the health of one's metabolism. Sudden or excessive weight loss after stopping Apetito could indicate an underlying medical issue, so it's advisable to monitor progress and discuss any concerns with your doctor in advance. Maintenance of a nutritious diet and lifestyle, rather than medications, are the optimal long-term approach to achieving a healthy weight, but in the meantime, I’d just be cautious and take it one step at a time.

[1] Use of cyproheptadine to stimulate appetite and body weight gain - A systematic review:
https://pubmed.ncbi.nlm.nih.gov/30825493/

[2] Efficacy and Tolerability of Cyproheptadine in Poor Appetite - A Multicenter, Randomized, Double-blind, Placebo-controlled Study:
https://pubmed.ncbi.nlm.nih.gov/34509304/

[3] Rebound elevation of cortisol following cyproheptadine withdrawal:
https://pubmed.ncbi.nlm.nih.gov/3584851/

Hope this helps!