Welcome to TID.
Like woodswise said, diet is what matters, This applies to everything, bbing, crossfit, etc. Don't use not being able to dial in your diet as an excuse.
For rock climbing, it depends what part of the country you're in. In the South East, Dahlonega, GA is great! The Army Rangers train there at Camp Merrill which says something.. They have a lot of civilian schools catering to folks from beginners to advanced.