How does a healthy diet and regular exercise improve health but also lower health care costs?

Given the overwhelming evidence, it seems obvious that we should all be physically active. It’s essential if you want to live a healthy and fulfilling life into old age.
It’s medically proven that people who do regular physical activity have:
up to a 35% lower risk of coronary heart disease and stroke
up to a 50% lower risk of type 2 diabetes
up to a 50% lower risk of colon cancer
up to a 20% lower risk of breast cancer
a 30% lower risk of early death
up to an 83% lower risk of osteoarthritis
up to a 68% lower risk of hip fracture
a 30% lower risk of falls (among older adults)
up to a 30% lower risk of depression
up to a 30% lower risk of dementia

To stay healthy, adults should try to be active daily and aim to achieve at least 150 minutes of physical activity over a week through a variety of activities.
For most people, the easiest way to get moving is to make activity part of everyday life, like walking or cycling instead of using the car to get around. However, the more you do, the better, and taking part in activities such as sports and exercise will make you even healthier.
For any type of activity to benefit your health, you need to be moving quick enough to raise your heart rate, breathe faster and feel warmer. This level of effort is called moderate intensity activity. One way to tell if you’re working at a moderate intensity is if you can still talk but you can’t sing the words to a song.
If your activity requires you to work even harder, it is called vigorous intensity activity. There is substantial evidence that vigorous activity can bring health benefits over and above that of moderate activity. You can tell when it’s vigorous activity because you’re breathing hard and fast, and your heart rate has gone up quite a bit. If you’re working at this level, you won’t be able to say more than a few words without pausing for a breath.