He reportedly had a deep disdain for his peers as well as anyone who was overweight.
https://thehill.com/homenews/news/420475-documents-detail-sandy-hook-shooters-grievances-obsession-with-mass-murder?amp&__twitter_impression=true(http://www.autoadmit.com/thread.php?thread_id=4152730&forum_id=2#37378960)