Workplace problem(for me): People talking about their diets

I am recovering from an eating disorder. I am getting counseling, attending a support group, and now seeing a dietician and trying to eat healthy, regularly, and enough calories. Even though I was making an effort to eat normally, it turned out that I was till eating fewer calories than I needed. I am increasing my calories in a few different phases and will eventually be on a diet to gain 10-15 pounds.
Several of the women who work at my workplace are obese or overweight. Many of them are on diets to lose weight. Some of them have had success with these diets and lost 20-30 pounds in the past several months. They talk about "bad" high calorie foods and "healthy" low fat, low carb foods. They bring salds with low fat dressing to lunch. If someone brings a treat, they talk about how bad that food is.
This really makes want to just eat salad for lunch, as I had been doing. Even if I had got up the courage to take a small portion of the treat, these comments keep me away from it. My eating dosorder thoughts come on stronger like "See eating that way (their diet, similiar to my "normal eating") is healthy. There is nothing wrong with eating like that."
I had been avoiding having breaks at the same time as anyone else. I pretty much can go on break when I want. I take breaks at the same time as others now for two main reasons: I want to break my anxiety over eating in front of others and I feel better about the work day if my breaks are more evenly spaced. Being around these people makes it hard for me though.
Would it be rude to tell these people that I prefer that they don't talk about their diets around me? Should I find other ways to avoid them?
They talk about their diets as they are normal, but would they be offended if I talked about my diet in terms of good and bad. I don't know. It may be healthy for them to lose 30 pounds, but if I lose 30 pounds, I'd probably be dead.

They have found a peer group that is helping them with their diet, and they're probably getting a lot of help and comfort out of that and I don't think they'd understand your problem. Just like any other peer group, they have made their own behavior the norm and they're not going to like your request to change.

Why not hang out with the people who are not on diets? There's gotta be some in any workplace.