This is where I think the change in environment is important. Food is cheaper, more easily available and calorically denser. Physical activity is down. Sleep qu

This is where I think the change in environment is important. Food is cheaper, more easily available and calorically denser. Physical activity is down. Sleep quality and quantity have diminished. Psychologists have done a lot of work on motivations, but mostly focusing on pathological cases which -- by their nature -- are the most difficult and irregular.