Are there chocolates that are zero sugar, does that mean that the person could easily eat them every day, without causing fat accumulation or harm in the gym?
There is chocolate that is 100% chocolate bar. That would contain cocoa and cocoa butter.
Cocoa is actually really good for you, as is cocoa butter; it’s the sugar that makes it bad. There’s nothing innately in chocolate that would effect you negatively in the gym or otherwise.
If you’re going 100% chocolate, though, I would aim for quality chocolate - hand roasted. You want it without the chemical that neuters the taste of chocolate, so it has a more complex taste. You can also enjoy 80-90% dark chocolate this way as well, since it tastes far better than mass produced.
*I’m a bit of a chocolate snob.