1 Set goals. 2  Just like with adult weight loss, the weight loss goals in children should be attainable, allowing for normal growth. 3  The goals should initially be small, so that the child doesn't become discouraged or overwhelmed. 4  A five to 10 pound weight loss is a reasonable first goal -- about 1 to 4 pounds per month. The goals should initially be small, so that the child doesn't become discouraged or overwhelmed. 2  A five to 10 pound weight loss is a reasonable first goal -- about 1 to 4 pounds per month. 3  Food diary.