The leanest cuts of foreshank lamb are about 3% fat, 21% protein (http://www.nutritiondata.com/facts-C00001-01c21BH.html). It is also a good source of Riboflavin and Phosphorus, and a very good source of Niacin, Vitamin B12 and Zinc.
So I guess the answer is yes if its a lean cut (but I have tried low fat pork, and it really lost all taste, so I don't know what will happen to lamb)
Who cares unless you have a cheap supplier. Costco sometimes has lamb legs at a great price. I prepare it with a spicy mint rub and smoke it with cherry and hickory mix. Once you try slow smoked leg of lamb you will not want to eat anything else.