"Why do some people age quickly, while others age slowly?" Professor Jung Hee-won of the Department of Geriatrics at Asan Medical Center, a popular guest on Korean shows like You Quiz on the Block and Sebasi, shares 22 daily habits for slow aging and a healthy later life. Everyone hopes for a healthy, energetic old age and wishes to age slowly. But many people follow one-size-fits-all health advice that doesn't suit their own bodies, unintentionally harming their health or worsening existing conditions. In his previous books, the author discussed various aspects of aging and the broader framework of health, but didn't cover specific daily habits in detail—since he believed there was already plenty of good information out there. However, after encountering so many patients—both in and out of the clinic—who were damaging their health through misguided efforts, experiencing more severe frailty than their peers, or suffering from multiple chronic conditions due to accelerated aging, he felt compelled to write this book. Building on the concept of intrinsic capacity explained in his previous two books, this book offers practical advice and strategies for effectively managing that capacity to slow aging and age healthily. Reversing accelerated aging doesn't require significant expense—anyone can achieve it through simple lifestyle adjustments. Organized around three key themes—eating efficiently, moving properly, and protecting brain health—the book introduces 22 health strategies that can be applied immediately to daily life. It's also packed with practical insights, including real cases and experiences from the author's clinical practice as a geriatrician, as well as answers to common questions about aging. The answers to slow aging are already hidden within our everyday lives. This book will serve as a guide for those in their 40s and 50s preparing for the next 30 years, empowering them to lead more active, self-directed lives. You eat all the "healthy" foods, walk barefoot, even hike on weekends—so why does your body keep feeling heavier, with worse digestion? Your eating and exercise habits might be wrong! If you experience any of the following, read this book right away: ✓ Your blood sugar isn't improving even though you eat healthy meals like brown rice and chicken breast. ✓ You take protein supplements, but your muscle mass isn't increasing. ✓ You walk 20,000 steps a day, but you're not losing weight. ✓ No matter how much strength training you do, your strength doesn't improve. ✓ You feel foggy-headed, and your memory has noticeably declined. Eating, exercise, and brain care methods that put the brakes on aging—follow these, and you could live up to 20 years healthier than your peers! Eating Efficiently: Focus on Quality, Not Quantity ✓ Set Your Dietary Goals Low-carb, low-fat, high-protein diets aren't beneficial for everyone. This chapter guides readers in setting dietary goals suited to their own bodies—whether for weight loss, body composition change, or gaining weight and muscle. ✓ Transition Gradually with "Three-Dimensional Fasting" "Three-dimensional fasting" is an effective method for preventing accelerated aging and slowing the aging process. By following the steps in sequence, anyone can easily manage their weight and prevent yo-yo dieting. Each stage's practical methods are explained in detail. ✓ Remember the MIND Diet The MIND diet slows aging and helps prevent cognitive decline. This section covers which foods to eat and how much, which foods to avoid, and how to structure meals—including how to apply the diet to Korean cuisine. Moving Properly: Start "Muscle Tech" ✓ First, Build a Body That Can Walk Properly Many people actually get injured from walking exercise due to incorrect form and posture. This section introduces the proper posture and technique for walking, along with muscle-strengthening methods to support it. ✓ Fix Your Sitting Posture Right Now Poor posture can create a vicious cycle leading to all sorts of health problems, while good posture positively affects not just the musculoskeletal system but the body and mind as a whole. This section provides detailed guidance on proper sitting and standing posture, along with common mistakes to avoid. ✓ Focus on Your Core and Glutes The core and glute muscles are the most important muscles to maintain for quality of life in old age. This section introduces 6 core exercises and 5 glute exercises you can do every day. Protecting Brain Health: Understand the Connection Between Brain and Body ✓ Find the Sleep Duration That's Right for You Without enough sleep, exercise won't build muscle, and dieting won't curb your appetite.