Don't tell thin women to eat a cheeseburger. Don't tell fat women to put down the fork.
Stop body shaming.
Skinny shaming is not OK; fat shaming is not OK. Stop judging women for how they look. It's not OK to tell someone they need to eat a meal or skip two. It's not OK to put down others.
Stop telling skinny girls how "lucky" they are.
Why are they lucky? Some women are born naturally skinny. This doesn't mean you can scrutinize them. This doesn't mean you can jump to conclusions and assume she doesn't eat. Telling her she is lucky to be so skinny is not going to boost her confidence.
Stop telling larger women that they need to lose weight.
You shouldn't tell a curvy girl that she needs to lose weight. She could be born that way, or have a problem with her metabolism. It does not make a difference what is wrong with her though, cause no matter what she is still beautiful. Telling her she needs to lose weight is not going to help anyone.
Stop saying "real women have curves."
Some women have them, some don't. It's as simple as that, and you shouldn't tell a woman without curves that she's not a woman. You shouldn't put women with curves on a pedestal either. This only causes conflict between women. Real women love what they are born with and treat other women respectively.
Stop jumping to conclusions.
The teenager you just called fat? She could have a thyroid problem. The skinny college girl you said was "too skinny"? She's recovering from an eating disorder. You never know what someone is going through, so keep your thoughts to yourself.
Women shouldn't hurt other women.
Skinny shaming and fat shaming are stratifications of the same issue — society wants women to pit against each other, to keep them obsessing over their flaws. Women need to help other women.
Stop telling women how they should look.
Every girl has struggled with body issues and confidence problems, and telling her how chubby/thin she is does not help. The truth is, no one asked for your opinion.
So instead of skinny/fat shaming every woman you see, compliment her instead. Compliment that woman for how beautiful she is. Make women understand that every body is beautiful. She was born that way, let her love her body too.