So I'll chime in here, but I'm not yet an "expert." I was diagnosed with insulin resistance when I was 31 after years of not being able to lose weight no matter what I did. I went on a mostly liquid medically-supervised plan and lost 75 pounds! But you can't do that forever. My doctor ended up closing his practice and I had a hard time translating my old diet into a world of real food. I would still try to eat healthy stuff but I still gained about half of it back. :/
I'm now on day 11 of Whole 30 (just finished day 11 really) and here are some improvements I can already see:
Less bloating. I wouldn't say I've lost fat in only 11 days but my post-holiday bloat seems to be gone. My pants are comfier than then were on New Year's Day.
I have crazy allergies. I'm allergic to dust mites, pollen, trees, grass, mold, and my cats. It stinks because I love my cats and I am a hiker. Even though I live in New England we've had a couple of decent opportunities to be outside this month, and my cats still sleep in my bed with me. Before I was ALWAYS at least a little nauseous from the post-nasal drip. It was just a fact of my life that I tried to control with a neti-pot and OTC sinus meds. (I used to get injections but I have new insurance with a deductible so I was waiting for the calendar year to restart.) Guys, I have NOT been queasy. I have not. It's crazy. This alone is a game-changer for me. Before I couldn't drink water on an empty stomach because I would feel like I had to throw up. I wouldn't go to the gym sometimes because I was afraid I was too queasy to do the weight-lifting. So this has been amazing. I can't tell how how my quality of life has changed.
I also have osteoarthristis in my knees. My orthopedist said that for now (it's a mild/moderate case) I need to just not do high-impact stuff like running and lower-body weight lifting (which stinks because I was getting STRONG), and treat with advil as needed. Sometimes my knees would be sore even if I just knelt on the floor for a few minutes, which stinks because I'm a librarian and that's part of my job. But honestly my knees feel fine. I'm not saying it's cured by any means. I did a workout video tonight and was reminded that I need to be ultra-careful of my form or there will be a stabbing pain if I twist the wrong way but my day-to-day stuff hasn't bothered my knees at all and they tolerate the few lower-body weight exercises my doctor said I could do.
After 11 days. Seriously. I know that insulin resistance, arthritis, and allergies area ll tied to inflammation, so clearly something I've cut out has been aggravating my body. I have a feeling it's sugar, and maybe the starches too. If this helps me to lose weight I'll be freaking thrilled. I shared what I'm doing with my doctor (I see him weekly so I do get weighed) and he told me that he has no problem with me cutting out dairy and breads and of course he doesn't mind me ditching sugar.
So that's my experience so far, for what it's worth. And I didn't have a carb flu or feel like killing people. I wonder if I'm doing it wrong? I feel pretty normal but I'm doing a lot more dishes than usual! Good thing I like doing dishes.