These stunning before-and-after photos show why this unconventional diet is taking the industry by storm

The 21-Day Fix is taking over the diet industry.

It comes from Beachbody, the same company that brought the world the notoriously intense at-home workouts Insanity and P90X. There's a nutrition plan that comes with the workouts, too.

The 21-Day Fix promises that, in just 21 days, you'll see major results — a claim that has come under fire.

The diet "is just what they call it — a fix. To maintain a healthy weight and mentality, you need to make a lifestyle change. I don't like the idea that the name deceives you a little bit here," Kait Hanson wrote on The Huffington Post.

But people post wild photos on Instagram to show how far they've come in a shockingly short period of time, suggesting that the plan could truly work.

Here's what you need to know about the diet trend:

SEE ALSO: These stunning before-and-after photos are helping an Instagram star launch a fitness empire

The workout schedule is pretty simple: You have six 30-minute workouts.

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They include pilates, yoga, cardio, and upper and body strength training. People who order the workout DVDs through Beachbody get a seventh bonus workout.

They're led by trainer Autumn Calabrese.

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She's a mom.

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Sure, Calabrese's physique may seem unattainable, but the fact that she, too, has to balance her schedule with raising a kid makes her more relatable.