For Fitness, Intensity Matters
Almost everybody wants to stay strong, fit, attractive, and ready for life. Avoiding carbs can keep you shapely, but it won't keep you fit. Walking is fine for the elderly for whom a long walk can constitute "exertion," but, otherwise, keeping one's muscles alive doesn't need to take very much time if done right.
The government should provide all of us sedentary cubicle-monkeys and couch-sitters with trainers for a half-hour daily, just as North Korea does. Daily government monitoring of our life-styles via in-home NSA-supplied video systems would be a good start. We all need more free services and more help from our moral and intellectual superiors.