You can love yourself but still wish to improve.
Accepting your body means loving your body!
acceptance and love are two different things, You could accept something but you may not like it or 'love' it. Similar to rules there are some rules in which you don't like, But we accept them.
You can love/accept your body while you also acknowledge the fact that there is still room for you to make healthy improvements.
I believe that you can love yourself and wish to improve yourself. In fact, I'll take it a step further and say that if you love yourself, You will look after your body and stay healthy.