Jessica Biel won't let her sons eat McDonald's

She told Parade: "I'm like, 'Sorry, guys, I'm not doing it.' They don't get McDonald's.

"I just feel like I don't know what's going on with [the] quality of that food. It's stuff like that that I'm like, 'No, we're not, Let's go have a great burger and fries at a fancy place. I'd rather pay more for you to have something fancy than something like that.'

"I guess I'm not crazy, rigid and strict, but that would be something that, if they asked me for, I would just be like, 'Next!' Next place. Next down the line.'"

Jessica - who is co-founder of wellness company KinderFarms, which offers medicines, electrolyte solutions and supplements without unnecessary fillers or artificial additives - is trying to adopt a cleaner approach to diet and wellbeing.

She said: "I just really believe in the products, and I really trust what's in them.

"And for me, I want to help my immune system the best I possibly can. And I don't want to put a bunch of junk in there.

"I don't want to put stuff in that I cannot pronounce. That's my new rule: I don't know what this crazy word is. I am not [putting] this word in my body or my kid's body, you know?"

Jessica's husband Justin was recently diagnosed with Lyme disease, and it has been revealed that the 43-year-old actress pushed the Mirrors singer to look for answers as he initially thought the exhaustion and pain he had been experiencing were part of getting older and the demands of his two-year Forget Tomorrow world tour.

A source told People magazine: "He's not 20 anymore. But when his symptoms worsened, he realised something deeper was going on.

"He pushed through for months before finally getting answers. The Lyme disease diagnosis brought clarity to a series of unexplained issues that he's been quietly dealing with."

But Jessica Biel "felt like something was off" with Justin's health and "encouraged him to get checked out".

The source added: "She could tell that he wasn't himself. She's incredibly supportive."