I am sold on flax seed. It's absolutely carb neutral for all you carb watchers. 4 g of carbs per every 2 Tbsp, but it has 4g of fiber so it's a wash. No sugar. No gluten. No cholesterol, salt, trans fats, and it has a whopping 2600mg of Omega 3-oils in every serving. What's not to like?
Studies have found that flax seeds may help lower total cholesterol and LDL cholesterol. There are links that suggest it may help reduce the incidence of breast cancer. The oils may help repair the lining of the intestines, which is good news for those with Crohn's Disease. Please note though that there have been some negatives associated with flax seed oil (the oil form, not what you get in flax seeds by ingesting) --- to be on the safe side you should get your oil by including flax seed, not flax seed oil, in your diet.
I buy Hodgson Mill's Milled Flax Seed. It's finer textured ('cause it's been milled ;-) and has to be kept in the fridge after opening. Since I'm gluten-free and don't bake, I get my flax seed from a shaker. I took an empty spice container with a shaker top, washed it out, then filled it with the milled flax seed. I sprinkle it in my soups and other dishes. I can't tell it's there. By adding it regularly, it, um, well, um, it keeps me regular.
I used to put Benefiber off-brand in a salt shaker and shake it onto my food, but then discovered that it had 4g of carbs and only 3g of fiber so I'm getting a carb with every serving. Plus, while it says it's gluten free, the label clarifies that it has less than 10ppm gluten. I guess it depends on how strict you are as to whether that's enough to have you swear off the stuff. It basically, from what I've read, just clumps up in your system. It's not like 'real' fiber. I just decided not to continue looking into it and switch to flax seed.
Wheat dextrin is actually an improvement for Benefiber users. The main ingredient used to be "PHGG" (partially hydrolyzed guar gum). Wheat dextrin is higher in fiber content. If you're not allergic, I'd recommend Metamucil over Benefiber. Metamucil is 100% natural psyllium fiber which can reduce cholesterol and in my estimation does a better job of grabbing stuff you don't want in your system as it travels through. Of course, if you're one to hit health food stores you can pick up psyllium fiber there. I find it funny that we're paying money for what used to be tossed on the ground and fed to animals. Of course, that was before we started processing all the goodness out of our foods, too.
Do your own research. Look into the benefits of flax seed. I think you'll discover that it's an excellent and inexpensive way to fix a whole lot of what ails you!