As for any low calorie diet, the person can complain of satiety problems, and suffer from cravings.
This diet presents a risk of deficiencies: be careful not to follow it for a long time.
Despite consumption at will, we get tired very quickly of the proposed foods.
If you suffer from a particular condition (metabolic, cardiovascular ...), it is advisable to take the advice of a doctor, before embarking on such a "diet".
The limit of the plansIn the vast majority of cases, the "diets" themselves are not really recommended by nutritionists or dieticians to lose weight. Because the diet is usually followed for a short time ... then, gradually, the person finds his old eating habits. Moreover the body, being in caloric restriction, will begin to "save" its caloric expenditure ... After a while, the risk is an increase in weight. What is called the yo-yo effect (weight loss-weight gain).
In fact, in case of overweight, from a dietary point of view, it is recommended above all to change certain eating habits and to stick to it, avoiding to engage in draconian diets. The goal must be reasonable, but achieved! Already losing 10% of its initial weight is considered a good result by nutritionists, and especially it will reduce the health risks of overweight.
Source: To our knowledge, there is no real scientific study evaluating the "soup diet". But it is based on known dietary principles. Anses. Treatise on Clinical Nutrition of Adults, Basdevant A et al, Flammarion Medicine-Science, 2001.