Containing 250kcl per 100g, lamb is fairly calorifc, and while it's an excellent source of protein it's also quite high in fat (20g per 100g). Because it contains lots of fatty acids, limit your intake to 2 120g portions per week. Parts such as the leg and rack are less rich than others. 

Lamb is a great source of minerals, especially zinc, which is essential for the growth and repair of tissue. It's also rich in Vitamin B12, which helps to maintain a regular amount of red blood cells, keeps your bone marrow, nervous system and intestines healthy. It also contains Vitamin B9 and Vitamin B3 which have anti-ageing properties.