Components of the diet related to changes in eating habits that characterize the modern Western world are important factors in the increasingly high prevalence of chronic disease, including obesity, diabetes, hypertension and as a consequence, chronic kidney disease. The healthy diets recommended for the general population to promote longevity (such as the Mediterranean diet), are defined based on epidemiological and intervention studies and are usually characterized by a relatively higher amount of protein than the usual Western diet. Unfortunately, very few clinical studies focused on diet-based strategies of prevention of kidney disorders. Furthermore, this review will propose that the concept that protein restricted diets decrease the risk of developing kidney disease in the general population is not supported by the scientific literature. Indeed, preliminary studies showing a positive effect of relatively high protein diets on risk factors for chronic kidney disease (particularly on obesity, hypertension and diabetes) point to the need for future studies addressing diets that could prevent the increasingly high prevalence of kidney disease in the Western world. On the other hand, there is a potential role for protein restriction in patients with established kidney disease, particularly in patients with significant decrease in glomerular filtration rate. The exact protective action of protein restriction in patients with established renal disease needs further analysis, taking into account the more broad effects of protein restriction (lower phosphate, acidosis, uric acid) and a more current definition of malnutrition.