The KH diet

She married sofa jumper Tom Cruise, allegedly gave birth in silence, and seems to have her every move governed by some random scientology rule, so it's no surprise that Katie Holmes's diet is as bonkers as the rest of her life.

According to reports, Katie has shed a whopping 18 kilos in recent months by following a super-restrictive eating plan - now known as the KH Diet - and other image-obsessed Hollywood skinnies are following her lead.

The diet
The best thing about the KH diet is that it's really easy to remember - because you basically only eat three things. Great if you have a rubbish memory and don't mind feeling half-starved (you may not even remember to be hungry!) But those with a resolve any less iron-like than Katie's will struggle.

So what does she eat?
Katie tucks into a bowl of carrot soup for breakfast, organic broccoli for lunch, and organic broccoli for dinner with a little steamed fish or tofu. And that's it. Doesn't that sound yummy? "The green superfood is the key," said a source. "She and Tom are buying organic broccoli by the bucket-load." Wow. We're jealous.

Exercise
Despite the fact that most of us would be weak with hunger existing on such a limited menu, Katie apparently has bags of energy. "Katie has had a hectic few months," said an insider. "As well as running around after Suri, she has been juggling work with a strict exercise plan." The super-svelte star is said to run for miles every day, which, aside from keeping her mind off her rumbling tummy, no doubt, burns off the minimal amount of calories she may have consumed that day.

The verdict
So, she looks good, but virtually starving yourself and running a couple of marathons every week is certainly not the healthy way to stay in shape. Do yourself a favour, Katie, and ditch the loopy diet and militant exercise regime. Before you really turn into a Posh Spice clone!