There are many facets and expert fields attributed to the term "health."
"Fitness and Nutrition" already covers are large range of physical fitness issues including exercise, nutrition, training, and physical wellness. Health-related questions are welcomed on that site as long as they fall within that "Physical Fitness" scope. But the site is not designed to provide specific medical advice.
To apply the the broader term "health" would suggest a site that also covers social and mental healthcare providers and general healthcare issues, including disease and treatment. That's not the focus or expertise of that site.
I would not want to expand that site to cover questions about disease, pharmaceuticals, aging, mental illness, or any other deeply-professional and complicated medical issues. Fitness & Nutrition has enough on their hands trying to attract experts to ask intriguing questions and provide competent answers.
With all due respect to the Health proposal, the example questions do not convey any coherent sense of what they are trying to be. The questions don't show any sign of contribution by experts in the healthcare profession; It's not a site for doctors or researchers or other healthcare providers. The proposal is filled with conspicuously layman-asked questions. That does not bode well for merging it anywhere.
Frankly, most of the suitable questions already belong on the Fitness & Nutrition site anyway. Those folks should just bring their questions to the Fitness & Nutrition site. But the Health proposal, as it stands now, is likely driving any chance it has of attracting an expert, professional medical community. It is in desperate need of a do-over.