IDK, people can downvote what they want. I unchecked the show upvotes and show downvotes options on the first day I made an account not gonna have a conditioned response to a number every time I post something or read a post, would highly recommend doing it personally.
If the downvoting seems suspicious like somebody might have used bots to mass downvote it, you can always message the instance mods as that would violate the instance rules of pretty much any instance.
I think the conventional wisom is diet is more important than exercise in losing weight, although I think most people would recommend working out once a week regardless if you would lose weight or not, basically any working out would be positive if you aren't at all, it couldn't hurt to do sit ups and push ups and see where that takes you.