Online you'll get a lot of advice to "dump" imperfect friends (family members and love interests too), but I think that's excessively harsh and unrealistic.

Instead, I think you have to look at your friendships and determine whether they're relatively balanced and mutually beneficial. And if not, what can you do to increase the benefit ratio and balance for you both.

Sometimes there is so little benefit and so much detriment that the friendship has to end, but even with very flawed people and very flawed friendships that's not always necessary.

Standing up for your own opinions or steering the topic away from conversations you find uncomfortable are just options that may balance and improve the relationship. If the friendship is already pretty balanced, you may decide you want to leave the situation exactly as it is (and do the mental eyeroll when you hear her nonsense.

Whatever you choose to do or not do, don't let her opinions weaken your confidence in your own beliefs and choices. Trust your instincts and expand your knowledhe (which will improve your instincts).

It sounds like she is trusting her instincts without expanding her knowledge. For her, there may be no harm in that, but it does mean you can't rely on her instincts to guide you.

Doesn't mean she's a bad friend, but it does mean she isn't the ideal health and fitness coach/role model.

I have one at work. She knows everything about everything and even interrupts conversations to put her 2 cents in. She is not a friend outside of work so I do not hesitate to walk away when she butts in. I do not engage her in any conversation that is not work related anymore.

I would set boundaries with your friend. Like you said, she is good in other areas so focus on those good luck!!

She sounds like an annoying goof, so hard to take that kind of person seriously.

Try not to let her get to you, you're doing great and only YOU know what works for YOU!