"Research suggests that adults who begin their day this way are healthier and happier than those who simply opt for a cup of tea and some toast before heading out of the door."
ADDED: I think people are misunderstanding response #1, which I think is the best answer. "It" doesn't refer to sex in the morning. It refers to the news (that sex in the morning is good for your health). Let's have sex in the morning because it's a good heath treatment — that's unsexy. Ah! The aggravation I get for being subtle!