Nothing more than that on their FAQ page [1] - but that's the first thing one should be interested in: where will that data end up, and how will it be used? Will you now get blasted by sponsored products for, say, vitamin supplements or fitness gear after you've been diagnosed with malnutrition or obesity?
And there's an even worse point in this: Amazon is already utterly, utterly dominant in online shopping, has a massive presence in cloud computing (made possible, in part, by the lackluster competition), is threatening to "go big" in physical retail as well [2]... just how much of our economy, of our daily lives, are we going to give to Amazon? Do we really want an Avatar-style economy, with a few select mega-corporations controlling every single aspect of our lives? How long until Amazon starts rolling out their own health insurance, made "cheaper" by abusing all your Amazon Shopping data to determine if you're living healthy enough by (blackbox) Amazon standards (judged by a blackbox AI) to be worthy of even being admitted? Can such judgements be appealed in front of a legitimate court of law, or will you (once again) be facing a giant corporation's useless helpdesk that only responds with boilerplate?
Yes, I'm drawing a bit of a dystopia here, but this kind of behavior is already common in automotive insurance, so it's only a question of time until it arrives in healthcare.
[1] https://clinic.amazon.com/help
[2] https://www.chargedretail.co.uk/2023/02/28/amazon-physical-r...