The hot topic of longevity is taking over social media so NBC News medical contributor, Dr. Natalie Azar, and TODAY nutrition expert, Joy Bauer, join TODAY to break down the science behind longevity and share tips for how you can improve your healthy years. They highlight the most important factors to increase your health span including sleep, diet, and exercise, and share small ways you can boost longevity like walking for 10 minutes after meals.