The calories available to the average American increased from 3,100 per day in 1950 to around 3,900 by the year 2000 – around twice as much daily energy as most people need, depending on their activity levels. Put another way, to avoid over-eating in today’s food environment, most of us would need to reject half of our allotted calories. Every day. This is not impossible but nor is it easy, given that it is human nature to eat whatever’s available.
