Welcome - that's a really good question. I'll take a stab at it although I may be completely off-base.
Sounds like blood sugar ups and downs. You get hungry, reach for a cookie (just 1
), or some crackers, maybe a tiny sliver of that left over cake, or a handful of chips. You're OK for a while and then the headache comes on. Try adding and/or substituting a hard boiled egg, a piece of lowfat cheese, some beef jerk - in otherwords protein in place of carbohydrate heavy snacks. Even if the fat content seems a little high it may slow the digestion and tide you over longer between meals.
Also water, water, water (OK flavored water is fine too.) Your headache may be associated with dehydration. As you probably know the first week or so you are losing a lot of water with those first few pounds. It's a good thing, but you need to keep the reserves refreshed.
If you have other questions or you think I'm full of beans (you wouldn't be the first) try posting your question in one of the other sections like women's corner, or diets - you will probably get an abundance of answers