All of those are difficult to come by in winter. And you'd be competing for them with the local wildlife.....
I don't think small mammals, fish and carrion are hard to come by in the winter. And none of those have a high suger content. I'd probably have issues with rickets, not bad teeth
...But it was just an example. There are many more areas in which humans have degraded....
yes, but you said rotten abcessed teeth within a year. I don't think so. Not even close.