"Most people today rarely step outside their comfort zones. We are living progressively sheltered, sterile, temperature-controlled, overfed, underchallenged, safety-netted lives."

Section: 1, Chapter: 1

"Comforts and conveniences are great. But they haven't always moved the ball downfield in our most important metric: happy, healthful years."

Section: 1, Chapter: 3

"In evolutionary terms, this property of palatable foods used to be advantageous in environments where food sources were scarce and/or unreliable because it ensured that food was eaten when available, enabling energy to be stored in the body (as fat) for future use. However, in societies like ours, where food is plentiful and ubiquitous, this adaptation has become a dangerous liability."

Section: 1, Chapter: 14

"When faced with chronic inactivity over the lifespan, as is common in modern industrialized societies...[our] lack of either exercise in general or cognitive demands during exercise may lead to capacity reductions or suboptimal capacity maintenance in the brain similar to those seen in other organ systems....Our brains adaptively reduce capacity as part of an energy-saving strategy, leading to age-related brain atrophy."

Section: 1, Chapter: 20