> but it's downright foolish to pretend that we are gaining weight for any other reason than that we are eating too much and exercising too little. Right, that

> but it's downright foolish to pretend that we are gaining weight for any other reason than that we are eating too much and exercising too little. Right, that's pretty obvious to most observers, but it's not the end of the road. The interesting question is why this is happening. Is the cause purely social (perhaps we're lazier, or perhaps large portion sizes occur purely by normalisation over time), or are there other changes to our society or what we eat that make over-eating and under-exercising more common?