GOP presidential candidate Donald Trump provoked a lot of reaction with his debate response to who is responsible for hacking into Democratic National Committee computers: "I mean, it could be Russia, but it could also be China. It could also be lots of other people. It also could be somebody sitting on their bed that weighs 400 pounds, OK?"

It was one of several references to weight during the Trump-Clinton showdown, probably a first for any presidential debate.

Trump defended his past insults about comic Rosie O'Donnell, which have centered on her size. Democratic nominee Hillary Clinton attacked his criticisms of former Miss Universe Alicia Machado, charging that Trump called the woman "Miss Piggy." (This morning Trump told Fox he did complain about the beauty pageant winner's body, saying, "She gained a massive amount of weight, and it was a real problem." Trump owned the pageant from 1996 to 2015.)

The 400-pound hacker reference puzzled many people and set off a Twitter storm -- "EASY, TRUMP! EAAAASSSY!!! MOST AMERICANS WEIGH 400 POUNDS."

But there were serious responses to what some saw as body shaming. The University of Pennsylvania released this comment from mental health expert Linda Lucker Leibowitz, the associate director of Penn GSE's Executive Program in School and Mental Health Counseling.

"Bullying has been a huge barrier to the academic and social/emotional growth of many of my students over the years. There should be zero tolerance for bullying and cyberbullying in the schools, and there are laws regarding this behavior."

It is depressing that so many teens, both boys and girls, agonize over their bodies. I once thought young women would eventually face less pressure because they were now recognized for being athletes, school leaders and AP calculus students.

While girls are acknowledged for a range of accomplishments beyond appearance, the pressure to be a size 4 hasn't eased and become more unrelenting due to social media where everyone is a judge and a contestant. Even Olympic athletes in Rio experienced body shaming on social media.

I have talked to parents, mostly mothers, whose daughters have faced hurtful remarks about their appearance. One mom discovered a social media list circulating in her daughter's middle school of "Girls who would be hot if they weren't fat."

Several prominent news stories about suicides of teenage girls have reported they became depressed when a nude or semi-nude photo shared with a boyfriend went viral, and they were being taunted not only for how they looked but for being “sluts” because they sent the photo.

(I am surprised at the resurgence of the term “slut," often now paired with "ho." A student's car parked at my local school once sported this charming bumper sticker: “My ex-girlfriend is a ho.”)

Body image affects boys as well. Research has found 33 to 35 percent of boys age 6–8 believe their ideal body is thinner than their current body.

A friend said her son will do anything to get out of PE because of the jabs about his weight. He begs to have all his orthodontist appointments during his PE slot. In taking groups of boys swimming, I've witnessed boys who wore their T-shirts in the water because they didn't want to be ribbed for not having "six-pack abs."

Here is a good list of the research on adolescents and body image.

I am not sure how we solve this. I think parents can follow all the smart advice to minimize negative body image, but it's hard to overcome the social media and cultural obsession that has now found its way into presidential debates.

Any ideas?