Can you give me subtopics on the development of lactose intolerance?

Question

I'm writing an essay and I need help with the subtopics. 

Answer 1

Lactose intolerance among females vs males 

Lactose intolerance among elderly people 

Answer 2

lactose intolerance among infants

among children

among adults

symptoms of lactose intolerance

home remedies

professional help

lactose intolerance and diet (different types of diets may have different degrees of lactose intolerance)

lactose intolerance in developing and developed countries

lactose intolerance in the U.S.