What can be the cause of lack of appetite in case of 2 year old kid?

Finicky eaters. Too much juice or milk decreases a toddlers appetite. Toddlers are also more likely to be "grazers" and eat several small snacks a day rather than 3 square meals. Talk with your pediatrician to make sure your child is plotting as expected on his growth chart. If the growth is fine, milk intake is around 18-24 oz/day and juice is less than 8 oz/day, try a balanced diet of small, frequent snacks.