So the next time you see a pin-thin celebrity bragging about her relaxed approach to eating, remember this:

They take drugs

When Lindsay Lohan was arrested on suspicion of drink-driving, police said they found cocaine in her pocket.

Paris Hilton recently admitted to U.S. talk show host Larry King that she takes Adderall for attention deficit disorder.

Both drugs are often used by women looking to lose weight. Hollywood's party girls always seem to have access to certain drugs known to help shed pounds.

At the moment, Adderall is the latest diet drug craze in Hollywood, and the number of celebrities addicted to it continues to rise.

Just about every female celebrity arrested - from Paris to Nicole, from Lindsay to Britney Spears - has had prescription Adderall in her handbag. It keeps you awake while killing the appetite.

For the jet-set, hard-partying girl it has become the miracle pill - one, however, with potentially dangerous consequences.

Even when taken as instructed, Adderall can cause psychotic episodes, depression and serious heart problems.

Eating disorder expert Carolyn Costin, who has treated many Hollywood actresses, says she's even seen a rise in "the drugs used for attention deficit being crumpled up and snorted".

Some celebrities also take Clenbuterol, known as "Clen". Commonly prescribed to treat respiratory problems in horses, in humans it can cause fat loss.

While Clenbuterol and Adderall create a slimming effect in the short-term, after a while, users report a sudden and uncontrollable weight gain. Having tampered with the natural metabolism, the drugs stop working.

Manhattan-based trainer Justin Gelband, who works with catwalk and catalogue models, says: "Diet pills and steroids are huge right now. After Kate Moss was caught supposedly doing coke, the modelling agencies started to crack down on girls using hardcore drugs like cocaine and heroin to stay slim.

"So now it's more diet pills and steroids; they are easier to hide and, if pressed, the girls can say that they have a prescription."