I haven't read a Kashi bar, but a couple of their cereals are ok while the others are average. (Thanks for the word suntereo.)
I hunted down bars a while ago. One guideline cited an ideal intake for fats/oils is 10% by calories for cardiovascular health--seemingly an extreme. I wonder, at that level, if that's enough lipid intake to help properly process various vitamins/minerals. I'm sorry; I forget where I saw it. I find that 20-25% of calories from lipids is do-able, per day. Many bars are lipid-heavy, proportionally (e.g. 170cals, 120 from lipids), or sugar heavy.
If you're looking for bars and reading labels, check what the protein & fiber look like. If you're looking for a meal replacement or a snack (5 eats per day type thing), I've carved my meal/snacks down to being a rough 250-400 calories each. I didn't actually count each calorie. Don't over-think it; just glance at portion size. With a bar, are you getting enough food for the session until the next time you'll eat? Good protein is harder to come by; sugar is not.
Regarding fiber, when "whole grain" became the rage, one realist cautioned people to read labels. Unlike lucky charms, a food was only potentially whole grain if there were 100 carb-cals per 2 gram fiber. (Why they didn't say 50cal/g, I don't know.) So, when you check sugar content, look at it in the context of sugar vs total carb & relative to fiber. Then, after all that, is there other nutrition in it? Are there enough various vitamins/minerals.
The first thing I read on a label for anything supplementary is for artificial sweeteners. They're a primary eliminator.
So, in short:
- No artificial sweeteners (sucralose, aspartame, asulfa-something K)
- no sugar alcohols
- no weird other chemistry (short list, msg, others)
- Lower proportion of calories from fats (by calories)
- sufficient protein (by mass, grams)
- Carb cals relative to fiber
- lower proportion of carb cals from sugar, by mass
- Sodium? vs potassium?
- Vitamins & Minerals, esp if meal replacement
I did a small spreadsheet comparing bars within the Odwalla brand.
(Stop laughing; I was curious.
) Their basic protein bar was the best within the brand. It actually has more potassium than sodium. Some other bars are either too sugary or too fatty. You will always be heavy in either of those, sugar or fat. However, that bar gets most of the protein from soy, which is not necessarily a good human food (especially if you're a B blood).