"Our food is being hijacked and they're telling you lies about what your food is," the actress says.

Since giving up meat at the age of 21, Alicia Silverstone has been a major advocate for going vegan—and she’s raising her 6-year-old son, Bear Blu, to do the same.

In a video for the nonprofit Farm Sanctuary’s Compassionate Meals program, the 40-year-old Clueless star explains why she is so passionate about this lifestyle. “I just have always been really interested in the truth in all areas of life,” she says as they eat veggie burgers and kale salad. “And so knowing the truth about where our food comes from is just so disturbing to me. Once you see it, there’s no way to go back from that for me.”

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Additionally, she believes that people in the food industry are intentionally deceiving the public into eating meat. “Our food is being hijacked and they’re telling you lies about what your food is,” says Silverstone. “It’s just constant lies so that you’ll make choices that go against your nature.”

When Bear is asked what his favorite thing about being a vegan is, he responds: “That you don’t have to eat yucky meat.”

FROM PEN: How Alicia Silverstone Maintains a Strict Vegan Diet For Her Son Without Judging Other Moms

Silverstone says she has no trouble feeding her child vegan foods, whipping up dishes like tacos and stir fry at a moment’s notice. “I can make all those things based on what’s in the fridge. You always have a bean, you always have a whole grain.”

“The amazing thing about it is that it’s turned me into a health nut, because you feel so good, you feel so different,” she adds. “So being able to do something that is good for the Earth, good for the animals and good for you all at the same time seems like such a no-brainer. It’s like the biggest ‘Duh!'”

The actress previously made headlines in 2012 when she posted a video of herself chewing up food and feeding it directly into Bear’s mouth from her own. “It’s his favorite…and mine. He literally crawls across the room to attack my mouth if I’m eating,” she said at the time.

And even as some have criticized the idea of feeding children a vegan diet, Silverstone has staunchly defended her family’s lifestyle. “[Bear] loves the food I give him,” she told PEOPLE in 2014. “He’s not being deprived of anything. For him, having amazing fruit is like candy!”