I've been low carb Primal (paleo plus cream and cheese, and 50g or less of carbs) for a few weeks. Prior to that, I was mostly WAPF, with some sugar.
I've been feeling dizzy and lightheaded after I eat. Usually within 5 minutes of eating. I'm not feeling faint, but I can tell a difference.
It doesn't matter if it is more or no carbs, low or high fat, or morning or evening (thou, my afternoon eating doesn't cause it quite as bad as morning or evening.). I've gotten the same feeling from a chipotle meat salad as a 1 inch square of brownie (I work on a bakery and had to try the new flavor.)
(if it makes a difference, I have a partial gastrectomy, in which part of my stomach has been removed, but I have the natural and functional entrance and exit.)
TO UPDATE: I got a blood glucose monitor, which regularly recorded blood sugar readings between 85 and 100, even after meals. I started eating more carbs to attempt an oral glucose tolerance test, and found that I would get dizzy and/or nauseous when my blood sugar was rapidly changing (falling or rising). It never got higher than 140, and never lower than 79, even with higher carb meals.
EDIT Again: I did an Oral Glucose Tolerance Test. Fasting: 79. 50 grams of carbs (jellybeans). 30 minutes 124, one hour 81 (I felt bad), two hour 73. According to the Hypoglycemia book, it is a mild form of hypoglycemia.
Could you get a blood glucose meter and check your fasting, then before a meal, right when you feel dizzy and then an hour and 2 after? Rule out blood sugar issues (even while vlc, it can happen) then we can it down.
Have you looked into gastric dumping syndrome?
"Gastric dumping syndrome, or rapid gastric emptying is a condition where ingested foods bypass the stomach too rapidly and enter the small intestine largely undigested. It happens when the upper end of the small intestine, the duodenum, expands too quickly due to the presence of hyperosmolar (substances with increased osmolarity) food from the stomach. "Early" dumping begins concurrently or immediately succeeding a meal. Symptoms of early dumping include nausea, vomiting, bloating, cramping, diarrhea, dizziness and fatigue. "Late" dumping happens 1 to 3 hours after eating. Symptoms of late dumping include weakness, sweating, and dizziness. Many people have both types. The syndrome is most often associated with gastric surgery."
Sounds like a good time to talk to your doctor.
Either sodium or magnesium deficiency can do this to me. Dropping grains eliminates a fair amount of magnesium, so that may be the culprit. Try 200-600 mg Mag Citrate or Glycinate before bed.
I often get this, too. I wouldn't say it is virtually every time, but usually after a meal. I have come to believe it has to do with blood sugar as well as salt intake. I have very low blood pressure, so when I consume salt I think it temporarily increases it, making me a bit dizzy. It sounds like what we have is quite similar.
Also- I drink TONS of water, about 10 bottles a day, or 20 cups (I weigh 175). I think this can sometimes lead to dizziness because it waters down electrolytes. I have always been prone to electrolyte depletion through sweating, and this feeling after eating is similar to the dehydration feeling.
Hopefully this helps and doesn't add to the confusion. I definitely think all three issues cause my frequent dizziness.
It sounds like you have a gut issue. I'd see a Doctor. Could be a gut infection, such as H. Pylori. Without labs it is all speculation. I've been having some dizziness and stomach pain around meal times and turns out it was H. Pylori. Until you see the Doc you should try adding some fermented foods and probiotics. I would also get your enzymes checked. AND STOP EATING BROWNIES. Gluten exposure can affect you for up to 6 months.
The fact that it was not present with other dieting, notably SAD, would suggest to me either that you're not taking in enough sodium or enough sugar (I know, gasp). I think there are a couple options. One would be to add some salt to your food or water (Morton's canning salt is iron free and what I personally use). Another would be to consider that a different approach and do some alternative reading to get a little more information (e.g. dannyroddy.com).
Any chance you could check blood pressure before eating, and again when the dizziness hits? I wonder if it could be postprandial hypotension.
If blood pressure isn't changing much, could it be that you aren't eating enough?
Perhaps the gluten is getting to you, and cutting back on it has made the problems more evident. Are you eating enough calories for your body weight? water, electrolytes, and quality sleep?
My mother has rheumatoid arthritis and the pain had gotten so bad that she had mostly lost her appetite. When she would eat, she would have to immediately have to lay down due to dizziness and rapid heartbeat. Her doctors told her to eat more, which didn't help at all as it just made her feel sick, fueling the food avoidance. She lost most of her weight and muscle mass and was feeling terrible all day. She took the suggestion of cutting out wheat, dizziness stopped. Fast forward a few months, weight and muscle are back, no symptoms unless she has wheat, and a steady appetite. When she does have wheat, it takes about a week for her to bounce back to feeling well again.
I just want to add that if you have only recently lowered your carbs, you probably had insulin resistance, and were excreting excess insulin when you ate. Your body may still be adjusting to your lowered carbohydrate intake and increasing insulin sensitivty. Therefore, it is still excreting more insulin that you need, causing these drops in blood sugar. Since blood sugar control is basically a giant feedback loop, every time this happens, your body will respond by releasing slightly less insulin next time. It may take a while but eventually it will all even out.
Generally this is more of a problem in the morning because your insulin sensitivity is greatest in the morning.
Until then, try and make sure you are getting enough fat and protein at every meal. It won't stop the blood sugar drop, but the slowness with which they are digested will give your body time to "catch up" after the blood sugar drop. If you don't recover quickly enough, eat some more easily digested proten (meat or eggs). Don't eat sugar because it will just throw off the cycle and your body will overcompensate.
And it will get better.