Flax seeds are a great source of omega-3 fatty acid, fiber, and protein. For my recipes, you will want to by ground flax seed meal, which looks like a golden, grainy, moist flour. If you're interested, the body can't digest whole flax seeds, and some studies say that it helps reduce cholesterol in women.
Why do I use ground flax seed meal so much? It is an awesome substitute for oil, butter, shortening, etc. Flax seed contains some fat, but replacing other fats with it reduces the overall fat content while adding a lot of fiber and protein. Your flax seed meal package my try to tell you a different ratio, but I have found that a 1:1 substitution of flax seed meal for other fats generally works pretty well. The measurements in my recipes are ones that I actually use and that my family actually eats!
I know purchasing a new ingredient makes me a little skeptical, but once I started using ground flax seed meal I have never gone back! I buy at 3 lb bag at Costco that lasts me about six months while the shelf life is over 18 months.
Does it change the taste of your food? Uncooked flax seed has kind of a funny taste that you'll notice in your doughs and batters a little, but it blends in pretty well when cooks and adds a mild, nutty taste and a slightly sticky texture.
I hope this answers your questions about flax seed meal and encourages you to give it a try so you can participate in the fat-reducing and fiber-adding benefits of my heathified recipes!