Does my friend have an eating disorder?

Well I have a friend and she seems really healthy, lots of energy, great body all lean muscle, seems happy I guess but one thing I noticed! she eats only every other day! I asked her about it she says it makes her feel better with more energy, and says she does have vitamin supplements and herbal tea in her water as well as a squeeze of lemon and she drinks alot of water. I stay over at her house alot and see what she eats, she is a fruit fanatic especially watermelon and berries but she eats every fruit, she has some seafood some rice some nuts/rice sometimes yogurt, she doesn't eat bad things really at all i cant remember ever seeing her eat anything bad other than kraft dinner once. oh and she loves coconut it's really funny when we went to the caribbean together all she ate was young coconuts she had like a million a day and instead of body cream she puts coconut oil all over her body hahaha. sorry i went off topic but um yeah i just find it weird that she eats only every other day its not like she needs to lose weight she has no fat except on her boobs and butt basically but she is not anorexic looking sooooo do u think this is a problem? also she is not obsessive with it like if she is going out somewhere and it is her non eating day she will eat in social setting or we went to italy and she ate stuff she doesn't eat usually so it is not obsessed. we are both 17 and french speaking so excuse my bad english! thanks :)