Comparisons are a trap.  They set you up to feel less connected to the person/people you are comparing yourself to because you are looking for the differences.  You'll always find differences between yourself and others if you look hard enough.  The dynamic becomes me vs them. 

When we compare our eating to others it's an unfair comparison from the beginning.  You are operating on an incomplete set of data.  You don't know what they ate before, will eat later, if they have disordered eating behaviors, medical conditions, high/low metabolism, etc.  There are way too many things that influence our eating choices in any given moment for us to be able to make a fair comparison. 

Body comparisons are also unfair.  Each of us has a uniquely wonderful set of DNA that makes our body what it is.  The idea that we all need to (or even can) look a certain way is ridiculous.  Diversity in body types makes us all beautiful.  Think how different the world would be if we spent less time comparing our bodies to those of others and wasting energy trying to conform to society's impossible standards. 

My advice – when you catch yourself comparing, acknowledge the behavior and redirect yourself to focus instead on connecting.  It will be much more satisfying.