Lamb is sweet and hot in nature and warms the kidneys which can help with energy. Lamb is nourishing and warming and is beneficial in cases of weakness and helps to promote digestion. Lamb is very helpful for cases of cold syndrome. eg hands and feet cold in winter, getting up frequently during the night to go to the toilet, poor circulation, cold sweats caused by low energy etc.
Lamb is bad for anyone with internal heat, ie hot nightsweats, allergy conditions, or even diabetes, rheumatoid arthritis. Lamb can be quite fatty and so not so good for people with high cholesterol.