I did a whole30 in February. I had picked up running again and lost 15 lbs in 6 months, then on the W30 I lost another 15 lbs.
The main reason I wanted to do the W30 is because I tend to get bingey on sugar. I am the sort of person who can flip a switch in my head and just cut something out entirely if it is forbidden, so this worked very well for me.
That said, I went on vacation and started up eating a bunch of non W30 stuff again and started to gain weight back. I kind of want to do it again but I think I will just force my cooking to trend W30.
Non-scale victories? Yes definitely energy, better, faster, stronger workouts. Clearer skin. Moods evened out after a few days.
The timeline they describe was fairly accurate. I needed naps at times, I found 'tiger blood' at a certain point as well.
I ate a LOT of eggs and used a lot of coconut milk. I also did trays of chicken thighs with salt, pepper and paprika. Those were my go-to items. I did go and buy some alternative flours and coconut aminos that were on sale -- didn't use the flours much and did enjoy the coconut aminos as a soy sauce substitute. After the program there's a much cheaper replica recipe that uses trace amounts of sugar I've been meaning to try.
At times I absolutely had to eat more than 3 meals a day. Do not worry about eating too much food. I did up sweet potatoes, roasted carrots and yams for when I was after something "substantial". Zoodles and cauli-rice are your friend. I didn't really miss any of the foods in particular, it just required work. And it is more expensive, but eye-opening.
What worked for me was making a big pan of something, eating a bit of it, then an hour and a half later finishing it off as a 'snack'.
Yes, they speak against 'snacks' but the thing is it took me about a week to be able to force myself to eat those huge quantities of food required in one go.
Also on Saturdays when I work and don't have time to have a real sit-down, I hauled out nut butters, bananas, coconut flakes, veggies, and little pieces of chicken. It wasn't "perfect", it wasn't "template", but it was what I needed to do to make it through the program.
EDIT: Beverages!! I almost forgot. Black coffee is not that bad. I cut it with coconut milk now but on W30 I drank it straight. Also, lemon juice in water is a lifesaver, and will taste amazingly sweet, so so so good.