1) If I eat a carb rich meal, I will happily go for a nap. Anecdotal evidence, had spaghetti carbonara with garlic bread at the weekend. Fell asleep watching a film for the first time in about a year. I can create the same effect with potato or rice. I don't like it. It wastes my time.
2) After eating a lot of bread I can feel extremely bloated and uncomfortable. I potentially have a gluten intolerance however I find the same when eating a lot of sugar. It could be yeast related. Through experimentation I've found that the white 'gacky' sliced bread is particularly bad.
3) I don't think we are designed to eat modern wheat. I switched from beer (ale) to cider and find I have no morning after 'bowel' effects.
4) I avoid sourdough bread. Who am I kidding. Best bread in the world. My crack cocaine. Thankfully there are some awesome artisan bakers in Bath, UK. However when I buy a loaf, I commit to a 20+ mile cycle ride.
5) If I eat a carb rich meal, I will get hungry quicker. I can feel 'fuller' for longer by avoiding carbs. It makes me avoid snacks.
A lot of the above is about feeling mentally alert at work/home. In the winter it means I cook up big pots of high protein stew, freeze them and take them to work and zap them in the microwave. Summer is all about big boxes of salads, heavy on the meat/cheese/dressing.
At work we have lunchtime Dirty Burger Wednesdays where we grab nasty takeaway food :) Like I said it's not about being religious about not eating wheat, just generally trying to minimise intake. I know what a high carb diet makes me feel like.
One proviso. I cycle to work. The morning is almost a free wheel 2.5 mile down hill ride. The evening is a 2.5 mile climb. It used to be a real bitch. Now only the last 0.5 mile is a bit nasty.