You need to lose a couple of kilos in a few weeks. The only solution: a strict diet with fewer than a thousand calories a day. You’re guaranteed to lose fat – but unfortunately you’ll lose muscle too. Italian researchers wrote in the European Review for Medical and Pharmacological Sciences that they have found a way to limit muscle loss during a crash diet: avoid carbs and replace them with protein.
The researchers got 18 healthy but overweight participants to go on a very strict diet for 3 weeks, consuming about 700-800 calories per day.
Nine participants were put on a more or less traditional diet: the energy was derived for 35-40 percent from fat, 15-20 percent from carbohydrates and the remaining 40-50 percent from protein. The participants consumed about one gram of protein per kilo bodyweight daily.
The other nine participants were put on a low-carb diet, where the energy was derived for 35-40 percent from fat, 5 percent from carbohydrates and the remaining 55-60 percent from protein. Half of the protein was given in the form of a whey supplement. The participants consumed about 1.4 gram of protein per kilo bodyweight daily.
The figure below shows the effects of the traditional crash diet.
The figure above shows the effect of the low-carb crash diet.
The figure below compares the results of the traditional diet and the low-carb crash diet. As you can see, the low-carb diet protected the muscle mass from breakdown. Both types of diet resulted in approximately the same amount of fat loss.
The researchers’ findings did not enable them to work out how a low-carb crash diet protects muscle mass against breakdown. They suggest that the combination of proteins and the lack of carbohydrates may lead to an increase in the anabolic activity of growth hormones.
“Our pilot double-blind study showed that a very-low-calorie ketogenic diet was highly effective in terms of body weight reduction without to induce lean body mass loss, preventing the risk of sarcopenia”, the Italians wrote. “Further clinical trials are needed on a larger population and long-term body weight maintenance and risk factors management effects of a very-low-calorie ketogenic diet.”
“As the full spectrum of metabolic effects induced by a very-low-calorie ketogenic diet is not completely characterized, new trials that are specifically designed to assess the combined effects of genotypes and dietary intervention are needed.”
Very-low-calorie ketogenic diet with aminoacid supplement versus very low restricted-calorie diet for preserving muscle mass during weight loss: a pilot double-blind study
OBJECTIVE: Obesity plays a relevant pathophysiological role in the development of health problems, arising as result of complex interaction of genetic, nutritional and metabolic factors. We conducted a dietary intervention case-control randomized trial, to compare the effectiveness on body composition of two nutritional protocols: a very-low-carbohydrate ketogenic diet (VLCKD), integrated by an aminoacid supplement with whey protein, and very low restricted-calorie diet (VLCD).
PATIENTS AND METHODS: The clinical study was conducted with a randomized case-control in which twenty-five healthy subjects gave informed consent to participate in the interventional study and were evaluated for their health and nutritional status, by anthropometric, and body composition evaluation.
RESULTS: The results of this pilot study show that a diet low in carbohydrates, associated with a decreased caloric intake, is effective in weight loss. After VLCKD, versus VLCD, no significant differences in body lean of the trunk, body lean distribution (android and gynoid), total body lean were observed (p > 0.05). After VLCKD, no increasing of sarcopenia frequency, according ASSMI, was observed.
DISCUSSION: Many studies have shown the effectiveness of the ketogenic diet on weight loss; even if not know how to work effectively, as some researchers believe that the weight loss is due to reduced calorie intake, satiety could also be induced by the effect of the proteins, rather than the low-carbohydrates.
CONCLUSIONS: Our pilot study showed that a VLCKD was highly effective in terms of body weight reduction without to induce lean body mass loss, preventing the risk of sarcopenia. Further clinical trials are needed on a larger population and long-term body weight maintenance and risk factors management effects of VLCKD. There is no doubt, however, that a proper dietary approach would impact significantly on the reduction of public expenditure costs, in view of prospective data on increasing the percentage of obese people in our nation.