There's lots of topics on how you came to paleo but what makes you stay with paleo when you've wandered off the beaten track?
For me it's the gas.
I was essentially asymptomatic prior to Paleo, but, at 57, knew the SAD was NOT the way to health and longevity.
Since undertaking Paleo (about 4 months) I feel better, lost 20 lbs., see better results from my workouts, and enjoy the knowledge that when I buy my groceries I am frequently supporting small(er) business, humane and environmentally responsible farming practices, and setting a good example for my two young adult children. And I LOVE the food!
So it simply doesn't occur to me to stop eating/living this way. It just wouldn't make any sense.
I stick with paleo because, from a mental standpoint, I just can't not stick with it. For some reason I have this mental complex were if I'm not exercising and eating at an optimum level I'm just not as happy as I would be knowing I'm doing everything right.
So basically, now that I know about paleo, there is no going back.
I love to question stupid generic wisdom and society in general...being paleo I pretty much get to flip off the food pyramid every single day. which gives me some satisfaction.
I want to live a long and healthy life. I want that because I have a son with learning difficulties & I want to be around long enough and stay healthy enough that I can care for his needs.
If I revert to eating rubbish (or drinking too much) the feeback I get is almost instant. I know I am damaging myself and that will curtail my longevity and quality of life.
If I drink more than a couple of glasses of wine it takes me more than a day to recover. I'm quite sensitive to milk and cheese (not cream or yoghurt). It brings on asthma. Who needs that?
I like feeling well, so on the whole I only break the diet when I'm being sociable and even then, not that much.
Everything about my body works better and feels better since I changed my diet. It's just not worth it to go back.
But if I had to pick one, it is the SLEEP. OMG the sleep. I used to go to bed and toss and turn for hours. Now I get into bed and I am out in a matter of minutes. And I sleep right through the night (of course I have three kids under 6, so occasionally my sleep is disturbed, but not like it was before).
This is an interesting question. I do not suffer from any known dietary issues - my whole life I've eaten grain, dairy, and legumes with relative impunity. This I mention not to brag but only to say that I don't have any pressing medical pressures to keep me on the straight and narrow. (Not that the weight loss is anything to sneeze at!) I came to paleo for a few reasons: Environmental/social, to boost my weight loss, and to generally simplify my life.
The first reason doesn't ever go away, even in paleo foods, but I'm in a better position to contribute positively - Farmers Markets help a lot of people (plus, the food tastes better.) Yeah, I could go vegetarian and stop contributing to the slaughter of animals, but I could also work toward boosting pastured meat and away from factory farms and still keep eating the protein I love. It's not perfect, but it helps.
The weight loss (100 lbs in 18 months, the last 5 of which have been more or less paleo) I attribute to eating less of the crap I used to eat; could grain, dairy, and legumes still have stayed in my diet and allowed me the same results? Maybe, but paleo gives me not only a plan to work from, but a good set of reasons behind it. I like evidence, and paleo makes a lot of sense.
As far as simplification, it's a two-way street to be sure, but I think the net effect is positive. By removing Pollan's "food-like substances" from my menu, I now think of food on a more basic level. I can do all of my shopping in two places - the Farmers Market and Whole Foods (the only place I can regularly get grass-fed beef). I don't have to worry about my apples being shipped in from New Zealand (not that I have anything against the Kiwis, just that there's nothing responsible about eating apples out of season from half a world away) and I'm not tempted by the piles of processed crap that used to stock my pantry. I just cleaned out my fridge after my non-paleo ex moved out - the effects of simplification are seen quite clearly in my easily navigated shelves.
Another note on simplification: it has made eating with others more complicated. There are some restaurants that are just never going to be on my menu - anyone ever get invited out for pizza after going paleo? Even with that I find benefits, though - those establishments that cannot possibly offer a paleo meal are generally low quality, fast food-style joints, and I feel better avoiding the corporate food chain (which circles back to point one.)
So there you have it. I stay paleo because I feel it helps me contribute to the restructuring of the food industry, I'm terrified of gaining weight back if I cheat, and, now that I've gotten used to it, I spend a lot less time thinking about the mundane aspects of eating.
Depression and anxiety are really the worst of what falling off the wagon does to me.
A clean diet is a large part of my mental wellness plan, and without it I just can't be the best version of myself. That includes everything from the "big stuff" like advancing in my career and forming loving connections in my personal life - down to the little things like being able to look someone in the eye without triggering my social anxiety.
It provides the clear, solid, healthy foundational state that allows me to make progress in all aspects of my life.
Luckily, or unluckily, I have a very clear reaction to anything gluten, as well as cow dairy. That reaction is quite nasty and obvious, so if I have it, I know I've been exposed to something bad. It includes things like loss of immunity to cold (and actually getting chills), brain fog, lack of energy, and the runs, and hellish acid reflux the night after.
I suppose the wonderful high energy of paleo is something I got used to, I still have it, but it's no longer as obvious after almost two years, but it is there when I need it, and gone when I accidentally expose myself to the bad stuff.
I suppose that having a baseline of feeling awesome day in and day out is something I've gotten used to to the point that anything that affects this negatively is very obvious. (As opposed to the early stages, where I was used to low levels of health and felt awesome soon after switching to Paleo.)
For folks that are asymptomatic it's less obvious, but of course the damaging health effects of SAD exposure are still there.