It sounds too good to be true — a diet that not only claims you can lose half a stone in three weeks while still enjoying pasta, potatoes and even the occasional glass of wine, but which also helps you lose weight while you sleep.
The Overnight Diet is the brainchild of Doctor Caroline Apovian, director of nutrition and weight management at the Boston Medical Centre. She claims that her patents typically lose 9lbs (4kg) in the first week, and every week after, without experiencing hunger or cravings — and that two of those pounds are lost while you sleep.
The secret to the diet is that it is specifically designed to protect your muscles, and stop them wasting away as you reduce the amount you eat. When the body detects a drop in food intake, it immediately turns to the muscles for extra energy — so while you are getting thinner, you are also getting weaker and flabbier. When the diet stop and the weight creeps back (as it typically does), it returns as fat rather than muscle.
According to Dr Apovian, the amount of lean muscle in you body links directly to your metabolism rate; the more lean muscle you have, the more efficient your body is at burning fat.
So how does it work? The diet is simple, it's divided into two parts, and for one day each week, you cut out food completely, instead drinking three smoothies, one for breakfast, one for lunch and one for your evening meal. Of course they are not any old smoothies, they are packed with protein to protect muscles and rich in fibre to aid digestion and keep you feeling full.
For the other six days, you follow a healthy eating plan built around protein (meat, fish and eggs) to nourish the muscles and feed to body. And it's during this stage you can still eat many of the foods you love, like potatoes and avocado, albeit it in smaller amounts.
As for slimming while you sleep — the smoothies on 'no-food days' have also been designed to reduce the body's production of insulin (high levels of insulin are often to blame when the body stores fat around the tummy and hips). So while you sleep, your body targets those problem areas in a week-long fat-burning attack.
It's well know that lowering insulin levels is good for your health anyway (excess insulin is a factor behind diseases like diabetes and heart disease), and there's another big benefit. It also helps flush out excess water from the body, to stop you looking and feeling bloated.