Raisins are shrivelled up grapes. You'd think with grapes and wine being so healthy, that raisins would also be healthy. Raisins are chock full of sugar!
Just 1/4 cup of raisins have 31g of carbs in them. Compare that to 2.6g for the same amount of watermelon, or 2.0g for the same amount of cranberry.
It always amuses me that marketing groups push raisins as a healthy snack - as if they were a "fruit". They have less than 2% of your US RDA of Vitamin C, 6% of your iron, 2% of your calcium and under 2% of Vitamin A. Many snack bars I know of have much higher nutritional values.
If you're going to send a snack along with a lunch box, look through our recipe lists to find other things that are both tasty and good for you. As much as I love raisins in cookies and muffins, as a food to in "in a block", they don't quite cut it.