I've been collecting data about my headaches and diet for almost four months now. I don't see any patterns - annoyingly, I get headaches nearly every day, so there's not much information - but I thought I'd post the data set and see if anyone sees anything. Here it is. Hopefully someone finds this an interesting problem.
It's written in note-to-self format (abbreviations like "strawbs" for "strawberries"; if I mention a complicated dish once then I'll shorten it when I eat the leftovers, as "pasta" for "pasta with artichokes and spinach and pesto"; times given approximately and not in a consistent form and often without specifying if they're a.m. or p.m., though they are in chronological order). Quantities aren't given, although if they're suspected to be relevant I may be able to remember specific instances (for unusual foods) or typical portions (for ordinary foods) - other details might also be recollectable similarly. I also don't notice when headaches go away, so I don't know how long they last except when they last all day or become noticeably worse during their course. My sleep schedule varied considerably over this period, but trends more night owl than early bird (for a while I was outright nocturnal). I moved three time zones west at the end of July, should that matter at all.
I'm not soliciting commentary on my diet except insofar as it can be compellingly related to my headaches.
ETA: Assume that every single day I'm drinking lots of skim milk. (2-6 cups depending on how much I eat and how it's spaced out.) There's a couple of exceptions, mostly when I'm in transit for most of a day or run out of milk, but not many and they don't seem to correlate with headaches.
Low carb is a relative thing.
Looking over your diet you seem to eat very little, for which I have a bit of jealousy--if I tried to eat like that my headaches would be from transitioning in and out of ketosis (I get mild headaches when I don't eat enough, and on fasting days they are most annoying) and you only eat meat (usually in the form of seafood) every other day or once every three or four days.
As I don't know you well, I wonder if this is circumstance (you're in depressed economic circumstances), or if this is a choice? I remember (but could be wrong) that you're somewhere out there on the Autism Spectrum, and many folks with ASD have food "issues" of one kind or another.
Either way, the concept of a low carb diet can either be targeting a specific and low amount of carbs a day, or it can be looking at the total energy balance consumed--to pull an example out of the air 20% carbs, 40% protein, 40% fats. Looking at what you've posted, and without actually doing the math I think that you're probably more around 10-20 percent protein, 60-70 percent sugars and carbs (you eat a good bit of fruit, but that's mostly fructose and glucose, not the longer chain starches) and the balance protein. I don't think this is a very healthy balance, but others with as much or more knowledge disagree. Whatever.
Either way it doesn't mean you can't eat crunchy stuff like pretzels or potato chips, it just means when you do you have to cut something else, or increase other things (diet, fats, proteins) to compensate. I guess if you eat a horrendously strict low carb diet those things are out, but this is more about goals than religion, no?
Given your current diet it may be enough to simply add calories and if you then start to see unhappy body-shape consequences modulate overall diet and exercise to adjust. As an example eat a 1/2 pound of chicken breast, a 8 ounce pork or beef steak, salmon and some other fish in comparable quantities every day. This will up your protein, and if you can find good pastured/grazed cattle and pork will increase your omega-3 intake and other essential fatty acids.
My two biggest downfalls where low-carb and gluten free is concerned is Pizza and Pretzels. Oh, and ice cream. The ice cream here in AUS is still made with real sugar and real cream. Even the stuff in the little stop-and-robs. Oh Man.
Pizza we tried to work around by accepting that it's not going to be "low carb" in that sense and restricting it to once a week. Gluten free we tried to solve by finding a gluten free pizza dough recipe.
That didn't go so well, so we're back to flour based pizza dough. Pretzels I can usually avoid, but they're in the junk food machines at work (the facility I work in is about 20 miles from the nearest other source of food in a secure building with armed guard etc. etc., so you pretty much either bring your own food or eat in the cafeteria) so I occasionally succumb to temptation. So what--the point isn't to be a purist, the point is to achieve specific goals, and with my waist the smallest it's been since 2000, I'm ok with falling off the wagon every so often.
The point is that if you can modify your diet enough to reduce the frequency and severity of headaches, it's an overall win right?
So there are two things wrong with wheat based grains. One is the gluten, which can cause Celiac or celiac-like responses, and the other is phytic acid. Now, there's a lot of BS on the net about foods and health, so I'm always skeptical about stuff like this but it seems that phytic acid reduces mineral (including iron) and vitamin absorption in the gut. There are two ways to get rid of phytic acid--soaking/fermenting, and avoidance. Breads and dough based foods made with long-rise yeasts will have less phytic acid than short rise yeasts. Beans soaked for 12-24 hours will have lower phytic acid than those soaked for shorter periods of times etc. etc.
Your diet doesn't appear to be horribly heavy in wheat based stuff, but you were diagnosed with iron deficiencies, so this plus some steak/beef if your dietary preferences allow it may help.
To more narrowing focus on the crunch part, once you address your overall energy budget and eliminate gluten from it, there are some things you can do to get the crunchy back in.
1) Rice based bread. Carb heavy, but gluten free. The stuff I got at Trader Joes was a rather dense bread and bit on the moist side for good toasting, but you might have some luck with it.
2) You're across the harbor from S.F.. Sourdough bread HAS to be done with a long-fermentation process (long enough to reduce the phytic acid content significantly) SF is the sourdough bread capital of the world.
3) Rice cakes. Yeah, the crunch isn't as good as crackers or toast, but it's there.
4) Sourdough crackers. Crackers tend to have a bit less overall sugar/carbs in them than bread, and sourdough crackers with cream cheese and smoked salmon is a marvelous breakfast.
Oh, that reminds me. One way of altering your energy/protein balance is to simply drink a protein drink/shake every morning and evening. I have been getting 5 pound bags of this http://www.trueprotein.com/Product_Details.aspx?cid=46&pid=536 and mixing 2 scoops with 16oz of water for breakfast every morning. The plain unsweetened stuff is like weak milk, which I don't care for, but can swallow. The unsweetened chocolate is much more palatable. I'd guess that with 2 scoops a day 2 pounds would last me a month. I bought 10 pounds last order, but just to see if you can stomach it 1 pound ought to get you along the way. Just to add--no financial interest on my part, yadda yadda.
One other thing to look for--and this may have come up before or later in the thread. Some folks are particularly sensitive to different preservatives, to caffeine or other stimulants etc.. Your food diary, while much more accurate than I could generate over that same time, lacks the sort of minute specificity that would let a doctor or a someone with far more knowledge than I pick out the one or two chemicals that are fucking with you.
I routinely get headaches of various kinds, some due to "whiplash" when I was 19, some due to swelling of the sinuses (some due to infections, some not) and finally I wake up most days with a mild headache (sort of like you describe where moving the head increases the pain, but lying there doesn't make it go away). Usually it will subside if I get up and get through the initial pain, but some days that's damn hard to do.
Good luck.
I wouldn't claim to eat very little. As I said, this diary doesn't include portion size - in particular, the word "candy" might mean several handsful over the course of a day, "ice cream" might be just a little or two bowls, etc. etc.
I'm a pescetarian.