Osteoporosis is a good example. Osteoporosis means that bones become fragile and are more likely to fracture. Although this disease is often discovered in older adults, its roots may actually be planted in youth. If you don't get enough calcium and vitamin D or lack exercise when you're young, your bone mass may be insufficient. As you age, bone mass loss accelerates, leading to osteoporosis. Therefore, developing good dietary and exercise habits from a young age is crucial to laying a healthy foundation for the future.