Alfredo Martínez. PHOTO: Manuel Castells

The moderate increase of proteins and the reduction of foods with a high glycemic index -such as refined flours or husked rice- help to maintain a healthy per diem expenses and not regain the lost kilos. research This is the result of a study by Alfredo Martínez, Full Professor of Nutrition at the University of Navarra, which has just been published in one of the most prestigious scientific journals in the world, the New England Journal of Medicine.

The study, which is part of the project Diogenes (per diem expenses, Obesity and Genes), is the world's most relevant analysis of long-term weight maintenance deadline after having followed a weight loss program per diem expenses . In total, research evaluated the eating habits of 773 families in eight European countries. Among them, Spain, where the work has been carried out since 2005 at the department of Food Sciences, Physiology and Toxicology of the University of Navarra.

The volunteers - 938 adults and 827 children - first lost 8% of their weight and then underwent five types of maintenance per diem expenses - all of them low in fat and with no calorie restrictions - which they followed for 26 weeks. The results, as explained by nutrition expert Alfredo Martínez, "showed that a modest increase in protein and a decrease in foods that provide energy quickly - they have a high glycemic index - makes it possible to maintain the kilos lost and, in some cases, even continue to lose weight".

The study's co-author also stresses that the conclusions "represent a change in the widespread idea that diets with a protein content of at least 30% are harmful". In fact, he adds that the volunteers who best maintained their weight and did not abandon the regimen were those with diets "moderately" rich in protein and low in sugar: "Even those who combined both parameters continued to lose kilos during the intervention", adds the professor of the School of Pharmacy.

Not all calories count the same
In this sense, the expert recalls that "not all calories have the same effect on the organism and both proteins and products with a low glycemic index have a satiating effect that financial aid maintains the per diem expenses over time". Both factors could explain part of the results of the study.

This work also suggests that the most useful thing to lose weight is not counting calories, but knowing that the quality of these calories is not equal, depending on the ability of food to be converted into energy once they reach the body. "Thus, for example, lentils take quite a long time to convert into glucose once they are ingested, so they have a low glycemic index," explains Full Professor of the University of Navarra. The same would be true in general for legumes, whole grains, fruits, vegetables, lean meats, etc.

The project Diogenes will continue its work to find out which individuals respond best to this dietary subject according to their genes, "a field that is already leading us towards personalized diets," concludes Dr. Martínez.