The high-protein diet and the ketogenic diet, both of which are low in carbohydrates (hypoglucidic), are generally effective in controlling weight and losing weight, as well as maintaining muscle mass (and increasing it, with exercise).
The Ministry of Health, in its study ‘Hyperproteic Diet and Hypoglucidic Diet‘-offers a valuable analysis of the merits and limitations of these dietary regimens, in their different versions. (1) Noting among other things the risks of the excesses that may result.
Protein, the daily ration
SINU (Italian Society of Human Nutrition) guidelines indicate the average protein requirement as 0.8-1 g/day per kg of body weight. Other studies recommend up to 1.2-1.5 g/day per kg, in the elderly population in particular, as noted.
The energy intake in a balanced diet–according to classical Mediterranean school–should therefore be divided between carbohydrates, fats and proteins in the respective shares of 45-60%, 25-35%, 12-15%.
High-protein diet, 5 standards
The high-protein diet is not the preserve of only athletes or overweight individuals who document themselves on the Web. Nutritionists adopt it under precise conditions, increasing the percentage of protein according to individual needs, up to 25-30% of daily Kcal.
Dietary protocols based on drastic modulation of protein and carbohydrate intake are classified into 5 standards.
1) ‘Pure’ high-protein, normoglucidic and normocaloric diets.
Only amino acid/protein intake is enhanced in this diet. This is the pattern used in competitive athletes, as well as in large burns and nephropathic patients (nephrotic syndrome).
Athletes, however, should know that ‘there is no evidence that beyond a certain limit (above 2g/kg/day) protein intake, in the healthy, athletic subject, will yield the desired results in terms of muscle mass implementation if not supported by adequate CHO (carbohydrate, ed.) intake.’
2) Hypoglucidic and low-calorie high-protein diets.
It is the typical dietary regimen designed for overweight patients. In the short term they are shown to be more effective, even in weight loss, than the normoprotein diet with higher carbohydrate content.
However, these results are not confirmed in the long term. According to studies of overweight individuals, the benefits would also be related primarily to limiting glucose and caloric intake, rather than to protein surplus.
3) Normocaloric ketogenic diets.
These diets, which are hypoglucidic and normoprotein, are adopted in patients with neurological disorders, in normal-weight individuals with insulin resistance or type 2 diabetes mellitus, and in women with polycystic ovarian syndrome.
Ketogenic diets show similar efficacy to the Mediterranean diet in achieving the goals of weight, glycometabolic and lipid offsets, and overall cardiovascular risk reduction. Maintenance is confirmed for the next 12-36 months.
4) Low-calorie ketogenic diets.
Very-Low-Calorie-Ketogenic-Diets are distinguished from normocaloric ketogenic diets by their very low carbohydrate content, even less than 30g/day per kg of body weight.
They are useful for achieving consistent weight loss and improvement of metabolic syndrome in a short time (6 months). They are indeed adopted in obese patients, including those with metabolic syndrome, in candidates for bariatric surgery, and in cases of epilepsy combined with severe childhood obesity.
5) Hyperproteic hypoglucidic hyperlipidic normocaloric diets.
Paleo, ancestral, Atkins and similar diets fall into this category. They are used for slimming purposes, but without unanimous approval from the scientific community.
‘Atkins-type diets and Atkins-like, with maximal carbohydrate restriction and high protein and lipid intake, have been associated with increased long-term cardiovascular risk mainly due to increased cholesterolemia, gastrointestinal system disturbances (nausea, constipation, and other microbiota alterations) colon cancer, central nervous system disturbances (especially sleep, circadian rhythm alterations)‘, warn the study authors.
Protein, without overdoing it
Consuming excessive amounts of protein, without medical advice, may pose health risks.
The side effects described mainly concern kidney function and the development of bowel, breast, and prostate neoplasms.
Marta Strinati
Notes
(1) Ministry of Health, General Directorate for Hygiene Food Safety and Nutrition – uff. 5, Technical Table on Nutritional Safety (TaSiN) et al. High-protein diet and hypoglucidic diet. https://www.salute.gov.it/imgs/C_17_pubblicazioni_3148_allegato.pdf
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".
