Although dark meat does have higher fat content than white meat, it has more vitamin B, iron and protein than white meat. Eating dark meat will not harm you as long as you add it in to a healthy nutritious diet.
White meat is better for you, there is less fat and more nutrients. Dark meat is fatty. That is one of the reasons you are seeing more fast food resteraunts switching to all white meat chicken.
Thigh meat (dark) and breast meat (white) are very similar in calories and fat within each ounce of skinless meat. Drumstick (dark) is much higher in both calories and fat. Dark meat has zinc, riboflavin, niacin, thiamin, vitamins B6 and B12, amino acids, iron. Dark meat has 11 times more zinc than spinach, which zinc has been considered as a potential nutritional treatment for early stages of cold and flu.