This site contains information on balanced bars and their convenience.
The chief health benefit of balanced bars is the balance of carbohydrates, protein and fat in the proportions of calories advocated by Dr. Barry Sears in his Zone books -- 40%, 30% and 30%.
They also supply a wide variety of other vitamins and minerals, and that's good, but they shouldn't be taken as a vitamin and mineral nutritional supplement. Still, they are a lot healthier than any candy bar.
I've seen allegations that they're full of sugar such as high fructose corn syrup and palm kernel oil. They don't contain high fructose corn syrup, but do contain some corn oil and some fractionated palm kernel oil.
Ideally, I'd live in a situation where I could eat a Zone meal or snack of whole, unprocessed organic foods every time I was hungry. Unfortunately, this is not a reality. Even if it could be in my home, where children are continuously snacking down everything there is, faster than anybody can go shopping, I spend a lot of time at the local Internet cafe working so we can have money to go buy all that food for the kids.
And I'm not always there at home either. Sometimes I have to travel. You can't depend on getting a full wholesome Zone meal and snack on the road or while flying to the other side of the globe. I go to other countries where they eat healthier than Americans, on the whole, but that doesn't necessarily mean a Zone meal in every airport or on every street corner. Even if I always even knew what I was eating, which I don't.
And the bars carried by Dr. Sears on his website are better, no doubt healthier, but also much more expensive.

I've been buying my snack bars from Wal-Mart, and it's been letting me down a lot lately. First, by staying in a new area, I learned that not every Wal-Mart carries the Cookie Dough flavor bars. They do carry a lot of other bars that claim to be balanced, but which are not. Some come from the Balance company and some come from ZonePerfect. But only the original line of Balance bars are actually Zone perfect.
I'd eat other flavors of those bars, but Wal-Mart has been carrying only Cookie Dough, I guess because it's most popular. Anyway, I'd gotten used to going to the one in Ballwin and, as a backup, the one in Maplewood.
Last week I went to both of those and came back with a grand total of three boxes of six. That's not enough! So I ordered four boxes (of 15) from Amazon. Because of the Memorial Day weekend, I thought I was going to run out before they came.
Fortunately, I discovered my local Schnucks Supermarket does carry them. Not only Cookie Dough, but Chocolate and some other flavors as well. I'd thought they'd be hideously expensive, but ran only $1.25 each. With tax, that's not a lot more expensive than buying through Amazon and paying shipping.
Amazon is still the cheaper place to buy balanced bars, and I just placed a order for four more boxes of 15 (Cookie Dough and Chocolate Raspberry, because it's cheaper than Chocolate for some reason), but I won't panic if they don't arrive before I'm out.
Balanced Diet Bars -- lose weight on proper balance of protein, carbs and fat.