Meal-replacement diets, where some meals are replaced with soups, shakes or bars, have been making a comeback. They first took off during the early days of space travel when the public became obsessed with the idea of a nutritionally complete meal in a single drink or bar. These products remained popular for most of the 70s and 80s, but gradually fell from favour as people began to question the health benefits of these diets.
Everybody knows that to lose weight you should eat less and move more. But, of course, it’s not that simple; the combination of today’s environment and human biology can make it really, really hard to shed pounds. To reduce diseases caused by being overweight or obese, society needs to change, but those changes will be slow to come. We need effective weight-loss strategies now.
People who regularly go on diets tend to lose weight initially but bounce back and even gain weight after stopping the regime. This phenomenon – dubbed yo-yo dieting – is associated with changes in metabolism and is one reason why the vast majority of calorie-based diets fail. But exactly what causes these metabolic changes has remained a mystery – until now.