I think you pretty much nailed it.  Fat people are impulsive pleasure seeking animals.  They have plenty of drive and motivation to seek out and devour the fatty, oily, sugary, and salty foods which they find pleasurable to devour, and no motivation to use restraint and discipline and to follow through with actual physical fitness.  Lazy is just a shorthand for this. Where food is concerned, we live in a utopia compared to our distant ancestors.  It just so happens that there is a large portion of the population who are so animalistic when it comes to being slaves to their baser impulses that they are unable to control themselves in such a relative utopia.  The result is they end up morphing into inhuman eat beasts.  We need laws and systems in place to save us from the very real damage that these people are causing to society.  I strongly suspect that if we don't put them in place now, they will be the cancer that brings about our collapse.