In a two-year study of over 800 families in New Zealand, young children and infants who were given sleep intervention were about half as likely to be overweight by the age of two years than those who received either general standard of care or advice on food, activity, and breastfeeding. Families who received advice about sleep were told how to help their babies learn to self-soothe by putting them down in a quiet, dark room and avoiding things like singing or holding them. Read more about this study in an article by Jack Woodfield.