Love mushrooms? The latest U.K. diet craze making waves in the Hollywood scene is the Mushroom Diet, aka the M-Plan. The buzz: lose weight without losing your curves. Sound too good to be true?

Embraced by stars such as Kelly Osbourne and Katy Perry, the diet claims to help women spot-reduce, slimming trouble spots such as waists, thighs, and upper arms while leaving your bosom intact. How? By swapping out your regular lunch or dinner with a mushroom-focused dish for 14 days.

However, experts are skeptical. "The diet is simply a low-calorie diet," New York City registered dietician Tanya Zuckerbrot told ABC News. "I'm sure you will lose weight, but the fact remains that no food in particular can create targeted weight loss. Whether it's mushroom or steak, the laws of thermodynamics dictate, if you consume less calories, you will lose weight, just not everywhere but your breasts."

Still the diet could be worse: "Mushrooms are an amazing food. One cup has only 25 calories and two grams of fiber," she added. "They are also a great source of potassium; one cup of mushrooms contains more potassium than a banana or a glass or orange juice.”