Promoting Healthier Lifelong Improvements in Food and Exercise Act of 2018 or the LIFE Act This bill amends the Public Health Service Act to require the Centers for Disease Control and Prevention to carry out a national program to conduct and support activities regarding individuals who are overweight or obese in order to make progress toward the goal of significantly reducing obesity. The activities must include training health professionals, educating the public, and developing and demonstrating intervention strategies for use at worksites and in community settings.