The Wendy Williams Show host was answering fans' questions on Monday's after show, when one viewer asked for weight loss tips.
Williams began, "My son said something to me this weekend that made me feel really good, but it's not going to steer me off my path. He said, 'Mommy, I don't even know why you go to the gym. ... Because you're already skinny, you've got no weight to lose. You don't need to go to the gym. Why do you go? It's just a waste of your time and your money.' "
The 51-year-old has openly discussed her yo-yo dieting and previously told PEOPLE that her weight struggles go back to her childhood: "My first diet was in the first grade! Tuna fish and mustard with yogurt on the side. Weight was a big thing for me to overcome."
In the video above (starting around 9:28), she continued, "I go to the gym because it's not about me losing weight at this point, it's about me trying to fight heart disease."
Beyond "lots of cardio" and Pilates", she revealed she has gone meat-free: "I can't say that that has made me lose weight because I already lost 50 lbs. in three years, which I find to be amazing. Because, of all the crazy diets I've been on, none have ever been as effective as [saying to myself], 'Just push back, fatso. Just stop eating so much.' "
"And I don't love food as much as I used to," adds Williams, who has dropped refined sugars, dairy and eating after dark all while she's "picked up on other great habits like juicing."
On a more general note, Williams told the viewer: "Slow and steady is the name of the game. It's not going to happen overnight. I no longer believe in fad diets, crash diets. I don't believe in diet pills. I don't want my heart to race and pop out of my chest. Yes, I did have a jump-start because years ago I did get the liposuction and a tummy tuck, but I have to say that, if there is a poster child for plastic surgery and the jump-off to a new lifestyle, it would be me."
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The Wendy Williams Show airs weekdays (check local listings).