To clarify, they still ate wheat, corn, rice and oats but never as flour. They also still ate peanuts and legumes, white potatoes and probably some soy but we were backpacking so I didn't see any. Also, no carb restriction, no trying to eat grassfed beef or anything like that.
The one guy and his once overweight wife were in a program called Food Addicts in Recovery Anonymous. They are instructed that each meal should include fat so he said he puts a quarter cup of olive oil in every meal to get his fat in. Out on the trail he was making yogurt in a plastic container in his sleeping bag at night, so dairy was still in. The other lady didn't say what exactly was her program. She wasn't doing it to lose weight or anything. She was already skinny and healthy. She had heard of paleo and everything else but rejects the idea of limiting grains, especially seeing other people limit so much less and get the same results. I found that observation interesting as well. We had a lot of good discussions about the health transformations we had all experienced and it was amazing how similar they were despite our different approaches.
Female, 5'3", 50, Starting weight: 163lbs. Current weight: 135 (more or less).
I can squat 192.5lbs, press 75lbs and deadlift 210lbs