OK, the reports of immune system issues on VLC is just something that I've been seeing increasingly reported and thought I should mention it.
There's no significant RS or starch of any kind in onion that I'm aware of. RS tends to be in foods that also contain digestible starch, such as potatoes, green plantains/bananas, cassava/tapioca, garbanzo beans and hummus, lentils, mung beans, glass/cellophane noodles, par-boiled or cooked and cooled rice, reheated rice and beans/peas, English pease porridge cold (boiled split yellow or carlin peas that have been stored in a cool/cold place for a day or more), French white bean cassoulet http://en.wikipedia.org/wiki/Cassoulet,
Irish fermented rolled or steel cut or whole oatmeal (http://www.thehealthyhomeeconomist.com/video-how-to-cook-oatmeal-the-right-way/
), hominy corn/grits, peanuts, and there's some in sweet potatoes. There's a list here that contains some more: http://freetheanimal.com/2013/08/resistant-starch-content-of-foods-other-anecdote-and-miscellania.html
These are also foods that tend to get minimized or avoided in LC diets. The RS content is highest when the foods are raw. If cooked, allowing them to cool for a day or more allows recrystallization of the fractal resistant starch.
There are also lots of RS-containing foods not commonly consumed in the northern USA, such as breadfruit, sago, tiger nuts (a sedge tuber that's edible raw and AKA chufas), poi (taro), African lesser yams (and other African tubers) and bambara groundnuts.
The two biggest problems with modern starches seems to be
1) plentiful high-quality African sources are largely unavailable outside of the continent
2) the resistant starch content of foods was greatly diminished with industrial heating and refining processing techniques (traditional processes, like those advocated by the WAPF, tend to preserve RS content)
I also used to think that maybe the GAPS type diets worked for me because of my Northern European ancestry, but I saw too many examples of other Northern Europeans who not only didn't need to do GAPS but even improved when they added more RS to their diets, and I saw too many people reporting problems in the longer term on ZC and strict VLC, to continue to take that notion very seriously. When I tried RS and experienced benefits, it eliminated the need for that hypothesis.
Do you have some examples of heavy fruits and heavy starches?
Carrots, parsnips, and beets are generally considered more sugary than starchy.
The fermented foods, potato starch and kudzu gravies, some carby and other plant foods and seaweed and your experience with the WAPF might indeed help explain why you have fared better than many ZCers and VLCers in the longer run. Plus, if you didn't have a history of antibiotic treatments, that would be another possible factor.