Explainer: The 'lose 10kg' diet that has a two-month waiting list.

How many times have we heard the same promises? You will lose so-many-kilograms in this-many-months; you will have a summer-ready-body (whatever that is) by December 1; you will shed the ‘stubborn fat’ in the places where fat is meant to be – the hips, the love handles, the stomach that has grown a baby, the thighs that keep you standing, the upper arms that can carry a workload but don’t look like sticks in an Instagram photograph.

Now, a company that is promising to deliver all these things in a “scientific” way using “healthy ingredients” has been granted a $300,000 investment for one-third equity on entrepreneurial show Shark Tank.

But, surely we’ve learnt by now: things that seem ‘so easy’ very rarely are.

Dual sportswoman Ellyse Perry shares her day on a plate. Post continues below.

With Be Fit Food, women can achieve “rapid” weight loss – losing between two and 12 kilograms in just two weeks.

You can save time, ordering meals that are filled with “clean, whole foods” that ordinarily are “very time consuming to prepare”.

Be Fit Food has made it easy for you to “get it right”, at a cost of $199 per week if you want to choose your own meals and $186.50 per week if you’re happy for the chefs to choose them for you, under the ‘Be Rapid Weight Loss Plan‘.

It’s trending, too. Since their television debut Be Fit Food has been inundated with orders – according to the company’s Facebook page, they are “sold out until September”.

“With Be Fit Food, we can help our customers create healthy habits, reduce empty calorie eating, boost their wholefood and vegetable intake and apply portion control for long term benefits once they finish our program,” co-founder, clinical dietitian Kate Save, told Mamamia.

Save, alongside bariatric surgeon Dr Geoff Draper, started the company because they were fed up with the shake diets that were the mainstay for fast weight loss and ‘guaranteed’ results… (Even if the ‘results’ don’t make it past the breakfast the morning after the event you were dieting for.)

“Our meals are formulated to be nutritionally complete with the right balance of macronutrients to support healthy, sustainable weight loss,” Save said. “Nutritional education is also a key component in affecting sustainable weight management, and we have a team of dietitians on hand to support our customers throughout their journey with us.”

But how different is Be Fit Food compared to the shake solutions they’re so eager (and being paid so much) to displace?

Yes, they use whole foods instead of liquids but their approach is still extreme calorie restriction using meal plans that are high in fat, moderate in protein and low in carbohydrates.

Their rapid weight-loss approach involves an intake of 800 calories a day to induce ketosis – a state in which the body doesn’t have enough glucose to burn, so it uses stored fat for energy instead. “The food we use in our programs means that Be Fit Food enhances the metabolism to be more efficient as we are encouraging the body to use its own fat stores as fuel,” Save said.

But, according to Australian dietician and nutritionist Susie Burrell, there are long-term risks with cutting calorie intake so drastically.

“The biggest issue is that a significant amount of muscle mass will be being metabolised when calorie intake is this low,” she told Mamamia. “The longer an individual sticks to such a plan the worse it is for their body composition and metabolism long-term.”

Lunchtime salad inspo – tuna, tomato & borlotti beans #nutrition #nutritionist #diet #dietitian #lunch @shapemeplan

A post shared by Susie Burrell (@susiediet) on Aug 20, 2017 at 6:21pm PDT

The National Health and Medical Research Council tells us the daily recommended intake for sedentary women falls between 1,800 and 2,000 calories per day, depending on age. With exercise, these numbers increase further.

According to Save, by cutting calorie intake by half for a period of two weeks, clients can expect to lose between two and 10 kilograms and the benefits will remain. “Studies show that people who lose weight rapidly initially are more likely to keep the weight off after two years compared to those who lost weight slowly, and this is exactly the approach we are taking,” she said.

In this, Burrell agrees. Extreme calorie restriction can help in weight loss, so long as the diet is short-term and not considered a long-term solution.

“In clinical practice, [rapid weight loss programs] are suggested for short periods of time only two to four weeks at most before a more sustainable method that protects metabolism long term is adopted,” she said.

And this is where you need to sit up and listen. How sustainable is the Be Bit Food approach?

“What do you do when you stop this program long-term?” Burrell asked. “Has it really taught you to control or lose weight? How likely is it that you will resort back to your bad habits once it’s done?”

She also points out ketosis can be induced, and wholefoods can be added into a diet, without paying hundreds of dollars each week to make it happen.

Save agrees there is no “miracle weight-loss potion” but she says there is “incredible benefit in eating nutritious whole foods leading to our customers gaining greater appreciation for and approach to food in the long term”.

“With Be Fit Food, we can help our customers create healthy habits, reduce empty calorie eating, boost their wholefood and vegetable intake and apply portion control for long term benefits once they finish our program,” she said.

Does it sound too good to be true? Almost.

Does it sound better than drinking only milkshakes for two weeks before undoing all the ‘progress’ with a single morning-after breakfast? Most certainly.

Would you try a diet that promises you could lose 10kg in two weeks?