[UfoTofU]

I don't think the direct relationship is fuel consumption and obesity as much as sitting in a car to get to a place that's walking distance in good weather or convenience seeking. What I mean is, you can use a fuel-efficient car and use less fuel. However, if you insist to drive everywhere, therefore not burning the calories you consume, you'll store fat. I've heard of people who are extreme enough to get in the car to drive to their mailbox in a suburb, not a farm, where the mailbox might be a quarter of a mile ore more away.

However, I can see why there is a correlation since the ease and familiarity of driving more effects greater fuel consumption.

A side note, I believe the fuel consumption that should be considered is the increased portion sizes. There is no reason to eat as much as Americans do, no matter what we eat. We're programmed to eat when there is abundance. There's almost always been abundance in the US