This weight-loss trend is dangerous. And it doesn't even work.

Image via Thinkstock. 

Walk into any health food store, and you’ll see them lining the walls.

They promise that you’ll lose weight. A lot of weight, in a short period of time. They promise that you’ll never feel hungry. That you’ll become revitalised, energised. That you’ll sleep better at night.

The only catch? You’ll be drinking two-thirds of your meals out of a straw.

That’s right. I’m talking about diet shakes – the umbrella term for every kind of ‘healthy’ drink that’s designed to replace a meal so that you don’t have to eat breakfast/lunch/dinner. You just empty a sachet into a shaker cup, fill with water and enjoy that instead.

These kinds of diet shakes have been around for ages, but more and more brands are jumping on the diet shake bandwagon – including Isagenix, the latest cult-health trend to hit the mainstream.

At face value, they tend to sound great – especially when they’re being sold on weightloss benefits. But as time goes on, more information is starting to come out about these so-called diet shakes – including the fact that they may not be so good for you after all.

Liked this post? You might enjoy…

The ultimate cleanse for people who hate cleanses (but still want to do one)

10 foods you never knew were healthy

Why your leftover pasta can help you lose weight

A new study from research company Canstar Blue found that one in five customers who bought weight-loss shakes actually PUT ON weight after using them.

58% of people did lose weight while using the shakes – but half of them put the weight straight back on after coming off the shakes.

That’s pretty concerning – so we went to Accredited Practicing Dietitian Lauren to find out exactly why this might be happening.

“When you’re using the shakes, you’re on a low-energy diet,” Lauren explains. “People then don’t know how to transfer that back into food. So when they do go back to eating food, they go right back to eating what they would normally eat, if not more, because they’ve had that restriction. They end up consuming more energy and they put on weight again.”

So really, these diet shakes are doing nothing to educate you about the amount of energy you’re getting from food – they’re just a short-term fix which, Lauren says, is completely useless for the general population.

"They're a waste of time and a waste of money," she says. "They're really not a substitute for a healthy diet, based on real food. Yes, they do provide some of the necessary vitamins and minerals, but it's not a long term thing and really there's no replacement for eating real food. When you're drinking most of your meals out of a straw,  you're missing out on a lot of things. It's just not fun."

The other problem is that these diet shakes are designed to be a one-size-fits-all solution - they're not going to suit every single individual.

"Often, these programs do allow you to lose weight but it doesn't help you to keep it off," Lauren says. "There's no education plan along with these diet shakes, there's no physiological help as to why you need to use these shakes. It's all negative."

But I really want to lose weight. So what can I do instead?

"It's all about energy in, energy out," Lauren says. "It's all about understanding that. You can cut your calories down and still eat real food. You can have a 200 calorie meal, it's just about learning how to do it - so lots and lots and lots of veggies, lean meat, fish, that sort of thing."

The problem, of course, is that it requires more preparation - and it's not the extreme kind of diet that's really popular at the moment.

"It needs more prep, more thought," Lauren says. "It's a lot more difficult and it's not sexy, quick or easy. But it can be if you've got the time or dedication to do it."

So if you really want to lose weight - but don't quite know where to kick off?

"The best thing to do is look for a dietician - they can tailor a diet to suit you and your daily needs," Lauren says. "Or go and see your doctor."

At the end of the day, diet shakes are always going to be around. But real, healthy food is going to be around too - and that's what we need to embrace.

The bottom line?

"We all know what's good for us and what's not," Lauren admits. "Unfortunately, putting it into practice every day is hard in our fast-paced lifestyles. But eating out of a sachet isn't going to teach us anything - we’ll see results, but it isn't helping in the long run."

You heard the lady. Put down the straw and pick up the broccoli.

What do you think about diet shakes? Would you try them? Have you tried them?

Knowing how to eat the right foods is a far healthier alternative to a diet shake regimen. And you might be surprised to learn some of the foods nutritionists give their tick of approval to: