Autism

Protein. Your brain has to work harder than most peoples and protein is good at repairing the tissue. I ate a lot of meat but its expensive now so lots of eggs, beans and chickpeas in my diet, and tinned fish, but you can get plenty of protein without meat

Vegan, for the animals. They don't deserve what we do to them, so it's worth the effort to stop exploiting them

Mostly just mitigate bad-texture and try to work around it. I try to try new things... actually had a problem with not eating for most of my life so now if I don't know what something's like I'll probably try it if it doesn't have some clear indicator of bad texture.

I also limit caffeine intake as per doctor's recommendation, replacing it with water for most of the day. Don't like water but it's supposed to be healthy.

Since I have absolutely no self control when it comes to food, I have no diet.

I love salt and know that I should reduce it a bit.

Not necessarily. You need salt. If you don't have medical issues due to salt, you should be ok. If you do, and your doctor agrees, then limit your salt. If you don't, then go wild. Salt is vital.

I tend to meal prep for my bad days as I'm usually taxed from society and work. If I don't meal prep, I eat convenience food or take away.

It does help with the energy levels and saves money. But that's about it.

Edit: I completely missed the latter half of the OP.

I haven't done much experimentation. I know caffeine calms me down and helps "grease the wheels" in getting my brain to function. Alcohol helps ease my social anxiety and helps me relax and unmask around my close friends.

I haven't found any diet that specifically eases autism symptoms, but meal-prepping when I do have energy does help for the times when I don't.

Original off-topic post below./edit

When I'm not trying to lose weight I just cut sugary drinks out of my diet. My biggest rule is that if I go to the fridge for any reason I must pour myself a tall glass of water and drink that before I get to enjoy whatever snack/drink/meal I went to the fridge for. I don't drink enough water of my own accord, and this helps offset that.

I live alone, so I don't buy any food I don't have a plan to eat. I can't stand food just sitting uneaten. The recipes I've come up with for meals require simple fractions of products I know I can get at the store, so I can, for example, buy exactly enough ingredients to make my favorite stir fry recipe four times and have nothing left over.

When I do try to lose weight, I've found the keto diet has been most effective for me to actually stick to it and enjoy it. Even when I'm not strictly keto, I still stick to keto snacks and drinks, and just let carbs be in my meals. I have very little self-control around snacks that are in my house, but I have plenty of self-control at the store, so I just don't buy unhealthy snacks to have at home. Left to my own devices I can and will eat Girl Scout cookies by the sleeve and drink a 2-Liter of soda in one sitting. When my friends visit for board games and leave their snacks here they will be gone within 24 hours. The recent popularity of seltzer waters like La Croix have been a godsend for sating my soda addiction, since I can get the mouthfeel of soda without the carbs or the carcinogens in "diet" soda.

If you’re veggie/vegan, make sure you eat enough protein. For an adult male, that should be around 100g/day as a probably insufficient minimum.

Also supplement B12, which is mostly found in animal products.

Mostly and more importantly, don’t blindly follow dieting advice from random people on the Internet. Do your own research. Take a blood panel.

I remember trying Keto for a while. After a year, I felt great and had good work ethics. Then COVID hit, and afterwards, I was too depressed to keep up with all the micro managing.

Now my diet includes anti anxiety and focus pills. :P

I seem to do better with higher protein intake. I also try to eat a gummy multivitamin each day to help with any deficiencies that may come from a less than well balanced diet.

Vegetarian

Haha oh yes… ARFID. Way less serious than it was when I was a kid, though

I mostly try to avoid sugar and eat mostly vegetarian/vegan (with supplements), lots of beans, chickpeas and the like. In the past, I thought I noticed some sensitivity to gluten, but I was never 100% sure about it - sucks, because pasta is so cheap and versatile. Also some fish and seafood from time to time.

There is a real risk of spiraling into unhealthy and expensive habits for me, when I get into a phase where leaving the house is hard or impossible for me, where I then order junk food after not eating for sometimes more than a day at a time, so I try to keep large amounts of canned, dried and frozen food at the ready.

Mostly just avoiding foods I don't like. Mushrooms and fish are the biggest offenders. Weirdly I do enjoy sushi. It's just traditionally prepared fish that gives me an ick. Smells and tastes like piss. Don't understand why people enjoy it.

I consume a ton of peanut butter. It's very calorie dense for almost no effort, which is good because I'm terrible in the kitchen and usually don't start thinking about preparing food until I'm already so hungry that it's beginning to affect my ability to think. Every morning I eat peanut butter on toast for breakfast and most days I have a PB&J sandwich for lunch.

I suspect that my wife's uncle has undiagnosed autism and he overcompensates for it. He would obsess about certain foods being connected with autism. He refused to ever eat at the same place more than once every few months and he threw a fit over the possibility of having a plain hamburger because he was overcompensating.