Can you really lose 21 pounds in 21 days?

That's the promised result of the book "21 Pounds in 21 Days: The Martha's Vineyard Diet Detox" — and with Americans always looking for the quick and easy when it comes to weight loss, interest is undeniably high. 

Basically, the program consists of a three-part detox program centered around consuming liquid meals (juices/soups) and supplements. By the end of the 21 days, not only are you supposed to have dropped a great deal of weight, but your body should also feel energized and toxin-free. 

All this for the low price of $213.95 (shipping included!). 

Are the red flags in your head waving yet?

"The contents of this book are every bit as outrageous as its title," writes Mike Howard over on DietBlog. "According to the author, 'Dr.' Roni DeLuz, the cause of our ill health can be summed up in one word ... toxins. Indeed, this glib obscurantist concept is the reason why we are so fat — not our poor food choices and overindulgences thereof (an afterthought) or our lack of intentional exercise (not even mentioned)."

Indeed, though the book is incredibly popular, many nutritionists warn that losing so much weight in such a short period of time is not considered healthy. 

"You might lose weight because you are taking in so few calories, but most of the lost weight will be fluids and muscle," says nutrition and fitness expert Pamela Peeke. "In the absence of adequate protein, your body has to get protein from some source, so it burns up its own muscle mass. And at the end of the fast, the dieters will weigh less — but their body composition will be higher in fat and lower in muscle."

Undeterred, comedian Steve Harvey announced this morning on his radio show that he was embarking on the program, telling listeners that he was already on day four. The host of "Family Feud" will chart his progress on Facebook and Twitter during the course of the 21-day diet.

If you're serious about losing weight and living a healthy lifestyle, the best way to do it is to exercise and eat a diet high in fruits and vegetables. And I won't even charge you $200 for that advice. 

See also:

Best foods for weight loss

7 celebrity diets

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

21 pounds in 21 days: Steve Harvey goes for it
But questions remain about the safety of this new detox diet.