Hi there!
I found that keeping a personal, pen and paper food diary didn’t work for me, because it’s so easy to not write in it on a bad day, and it made me focus on food even more, when I’m trying to move my focus away from food, so that I’m not thinking about it all day! But I find a journal on here best, you can give a rough outline of what you’ve eaten and tell everyone when you’ve had a binge, but it’s motivating because you have people to be accountable to, which you don’t have in a personal journal (other than yourself!). Also, writing a journal on here means the focus isn’t purely on food, because you can tell others about your day, any worries you had regarding bingeing, and get some great advice and feedback in return. So for me, keeping a journal on here is the only kind of diary that has worked.
But by all means give it a go if you feel you want to, everybody’s different so it may work really well for you 
Good luck!