You've heard the old school rule: to lose weight, you need to <a href="https://health.gov/dietaryguidelines/dga2005/healthieryou/html/chapter5.html" id="88849ba9-e6b9-3b3f-a4c1-084f2450ffb6"> eat less and move more </a> . And when it comes to shedding pounds, calories do count.