Jennifer Aniston swears by her “wonder smoothie” for a better body, Liv Tyler relies on green juice for clearer skin, and Victoria Beckham is said to maintain her trim figure by sticking to a strict gluten-free diet.

While these beauty secrets may sound tempting, our advice is to wait a second before you try them. Health experts warn that celebrities’ beauty tips do not work for everyone, and, if used in the wrong way, could actually harm your health.

Wonder smoothie

US actress Jennifer Aniston is the envy of women worldwide with her toned physique and glowing appearance. So when fashion magazine Grazia earlier this year revealed that the secret to Aniston’s ageless beauty is a “wonder smoothie”, the drink became all the rage.

A source told the magazine that the drink consists of fresh, organic vegetables – beetroot, cucumbers, spinach, garlic, carrots, celery and kale. The star drinks nothing else on one day every week to purify her body.

If you’re doing it Aniston-style and eating normally for most of the week, it probably won’t do you any serious harm, but a juice fast that lasts a couple of weeks, or even just several days, could do you more harm than good, say health experts.

As soon as you pulp any fruit or vegetable, you lose all the fibre in them. “With no fibre in your diet, even after a couple of days, constipation will become a problem, and in the long term, your cholesterol levels could be affected as fibre helps keep them low,” Natalie Jones of the British Dietetic Association told the Daily Mail.

If that’s not discouragement enough, you could also find your hair starting to fall out two to three months later, warned hair care expert Philip Kingsley.

Raw mushroom diet

British movie star Pallet Roxanne has recently revealed that in order to maintain her ideal, slim body, raw mushrooms have become a daily intake.

The star told Female First magazine that in just over two weeks of regularly eating raw mushrooms, her body weight dropped. She takes mushrooms with her wherever she goes.

Roxanne is not the only fan of the diet. US pop star Katy Perry also admitted to using mushrooms to stay in shape.

It’s true that mushrooms are an excellent source of B vitamins, which are needed for a healthy diet, and their high level of dietary fibre can keep us from feeling hungry for longer. But health experts recommend mushrooms should be eaten cooked.

“Cooking mushrooms for even a few minutes dissipates most of the mild toxins they contain,” US nutrition expert and family physician Dr Joel Fuhrman said.

Gluten-free diet

The increasingly popular gluten-free diet, which cuts out the protein found in wheat, barley and rye, is favored by a host of A-list celebrities – US actress Gwyneth Paltrow, British fashion icon Victoria Beckham and New Girl star Zooey Deschanel, just to name a few.

The diet is believed to be a reason why these stars look so slim and fit. However, a new survey by The Sunday Times shows that gluten-free products could be causing some of us to pile on the pounds.

The survey found most gluten-free products in supermarkets – such as gluten-free bread and biscuits – are higher in fat than the equivalent standard products.

“Without gluten to bind food together, food manufacturers often use more fat and sugar to make the product more palatable,” explained Shelley Case, a nutrition expert.

So what about those naturally gluten-free foods, such as meat, fish, fruit and vegetables? Are they going to help us slim down?

It seems not. Tanya Thomas of the British Dietetic Association told the Daily Mail: “People assume that by cutting out gluten they are going to lose weight. It’s a myth.”