Are you looking for something to grab when you are running late and such, or are you trying to lose weight by eating these on a regular basis?
I suggest you look at the calorie count in many meal replacement bars. For the same number of calories you could have some "real" food. Not a Big Mac, but certainly a piece of fruit and some protein and maybe a healthy carb. Many of those meal replacement bars have 220+ calories. I can have a small meal/large snack for 220 calories.
For example, my breakfast this morning was 1/2 C lowfat cottage cheese (90 calories), 1/4 C crushed pineapple (not sure about calories, but probably under 50), and a Vitamuffin corn muffin top (100 calories). That's about 240 calories and it was mostly real food! And it took me more than 2 minutes to eat it. Waaaay more satisfying than a bar. I got a 1/2 serving of fruit, a serving of dairy/calcium/protein, and some grain (although I don't think Vitamuffins count for a whole grain). That with a cup of tea is delicious and satisfying. And a lot more chewing and swallowing than a bar.
I do keep Luna bars in the house for when DD is running late in the morning. At least I know she has had something reasonable for breakfast. I have had them once or twice, but they are gone quickly and I know that even if my belly is fully enough, my mind is still looking for something else to chew.
If you must eat them frequently, be picky about the ingredients. No HFCS, no trans fats, no preservatives, no artificial sweeteners. Preferably whole grains, nuts, dried fruits, maybe some dairy??
HTH..............P