Editor's note: Richard Simmons is a popular health and fitness guru and Emmy-award winning TV personality. He operates the Slimmons exercise studio in Beverly Hills, California, is the author of several books, including cookbooks and an autobiography, and maker of exercise videos.

(CNN) -- I am a big fan of George Lopez. I think he is a terrific comedian. I have watched many of his shows, and they made me chuckle.

I was so sad to see the recent clip where Mr. Lopez made fun of Kirstie Alley's weight. I actually was shocked at what he had to say. And I felt very sad for him.

Kirstie has been up and down the scale many times, and right now she is on an upswing. She has lost 60 pounds getting ready for her appearance on "Dancing With the Stars," and she will continue to lose weight because she will be on the show for quite a while. She can joke all she wants in response to Mr. Lopez's unkind remarks, but I know they hurt her.

Kirstie Alley slams George Lopez for pig joke

You see, I know how Kirstie feels.

It was in the late '50s that someone in my grammar school called me " a big fat pig. " At first, I did not know what these guys meant. But it did not take long to figure it out.

And what do people do when they are called a fat pig? Eat.

I was so upset that day that I went home, fixed myself three fried bologna sandwiches and opened a large bag of potato chips. And while I was stuffing my face from sadness, I tried to figure out why on earth someone would be so cruel as to call me a name of a farm animal. And that was not the only name that the guys bullied me with. They called me fat cow. Once they went outside of the barnyard into the circus tent to call me an elephant.

But none of those names bothered me as much as "pig" did. Pigs ate all day and wallowed in mud. Why, that wasn't me!

The name calling continued in high school. It accelerated to some foul language that always came before the word pig. And I tried to look like I took it all in stride and tried not to let it bother me, but it did.

Comedians have told fat jokes for centuries. And you know who laughs at fat jokes don't you? Thin people. Overweight and obese people don't laugh hysterically when they hear a fat joke. Especially now, when there are more overweight and obese people in America, fat jokes have no place in our society.

When people in a position to influence the way other people think -- people who appear on TV in front of a big audience -- ridicule someone for the way they look, they are telling everyone watching that it's acceptable to do that. And that's not funny.

Fat jokes hurt people just like they hurt me beginning in sixth grade. I think of myself as not only a teacher but as a comedian. I love to make people laugh. Now, I tell a lot of jokes, but they are mostly making fun of me.

I hope in my lifetime we can all continue to laugh at ourselves and not put down anyone for what they weigh.

The opinions expressed in this commentary are solely those of Richard Simmons