This book explains the fundamentals of maintaining mental and physical fitness, as well as how to improve your sleep, food, and bad habits in order to live a long, fulfilling, and healthy life.

The "new science of happiness" has received a lot of attention, but what about the "new science of health"?
For example, you can be healthy if you exercise regularly and follow healthy diet. You can be healthy if you have good relationships, learn something new, and are happy.

People who are mentally fit have better memory, concentration, and motivation. They also live longer.

We can't change the genes, but we can change our habits.