Aside from staying within my calorie range for the day, I have this little rule I stick too: If I've already eaten something that day, I don't eat it again that day.
For instance: if I had yogurt for my morning snack, I don't have one in the afternoon. If I had a piece of dark chocolate after lunch, I don't have one after dinner. If I had a huge bowl of strawberries with lunch, I don't have another huge bowl after dinner... you get the idea.
I'm not sure when or how I came up with this, but it has helped me avoid binging (on any one thing at least) or mindlessly grabbing "just one more" and keeps me mindful of variety in my diet. Well, as much variety as a creature of habit like me can tolerate anyway.
I don't have any eating rules, actually. Well, except trying to limit sweet treats to the first weekend of the month - the calorie bomb treats, like milkshakes, pastries, candy. Once a month, I get what I want, no guilt. But other than that, rules make me nervous. I start freaking out and end up bingeing. I'm weird about food. 1164 days ago
Oooh that's a really good rule. Hmmm....I don't know if I have any rules like that. I mean, I try to eat some kind of whole grain at each meal plus either a fruit or a vegetable and some protein of some kind...but it's not really a RULE nor is it particularly clever. I'll have to remember your rule!