"We're all human. I don't think you should beat yourself up if you make a mistake or if you have a potato chip," the American Idol judge tells PEOPLE. "Everyone wants a cookie or a piece of cake or fried chicken every once in while. It's not about that. It's about consistently and always trying to be better and trying to do good."
Lopez is well aware that her access to "all kinds of trainers" and knowledge of "all the great products" helps her stay motivated, but she's not keeping that information to herself.
"Summer is coming, and everybody's going to be in their bathing suits soon. And I love sharing the things that I've learned," she said in explaining the launch of the #BeTheGirl fitness challenge by her new lifestyle brand, BodyLab. "I'm really privileged to get a breadth of knowledge, and I want to share that knowledge with others."
And Lopez isn't afraid to practice what she preaches.
"I'm in the challenge with you," Lopez says of the 10-week program . "I'm going to be there [through the website and app] trying to push you along and be your cheerleader and be your support and telling you what to do and showing you exactly how to do it. This is something everyone can do. Sometimes you just need a little motivation."