Diet and weight loss, the latest news from international experts, from microbiota to smartphone apps





As the reopening starts and the warm season approaches, websites and media are full of advice on the summer diet, often based on approximations and excesses that can pose health risks and serve no purpose. In recent days, the experts gathered in the international Nutrition 2020 conference, which this year took place online, discussed the main news in the food sector, which has been summarized by EurekAlert!


Does the diet you would like to do ensure a sufficient amount of nutrients? It is essential to maintain an adequate intake of micronutrients. A study randomized and controlled trial presented at the conference by researchers at the California State University of San Bernardino, conducted on 54 obese volunteers with a body mass index of around 36, showed how easy it can be to run into dangerous deficiencies. The participants were in fact invited to follow a diet rich in fiber, with many legumes, or a low-carbohydrate diet for one year. The result was that both ensured weight loss, but also caused some imbalances and deficiencies. In particular, those who had followed the low-carb regimen got more niacin, thiamin, and vitamin K, while the others got more folic acid, magnesium, and copper. All participants consumed lower than recommended doses of vitamin D and E, copper, calcium, and magnesium.

Eating healthy doesn't have to become an obsession. Orthorexia, the eating disorder that causes those affected to be obsessed with the idea of ​​eating only healthy foods, can be an "undesirable effect" of a diet to lose weight. An online survey of 400 female students showed that three-quarters of them had some manifestation of orthorexia that started following a weight loss diet, while among those who had not tried to lose weight the percentage was much lower, around 40%. Additionally, girls trying to lose weight more often had some signs of another eating disorder.


What role do intestinal microflora bacteria play in trying to lose weight? Not much was known about the subject so far, but a study conducted by researchers at the Bloomberg School of Public Health at Johns Hopkins University in Baltimore shows that microflora may indeed play a role in diets. Specifically, the authors observed what had happened to 36 people who had followed a diet for six months and saw how the 12 who had reached the set goal, namely the 5% weight loss, had a composition of the microbiota different from that of those who had not managed to lose weight. In particular, of the 30 strains analyzed, Eubacterium coprostanoligenes were found to be more favorable to weight loss. (the more present the better the outcome) and the bacteria that help produce secondary bile acids, butyric acid, and succinic acid. Conversely, those of the Ruminococcaceae family are less present, and the greater the weight loss.

What role does physical activity play when you want to lose weight?  Bad news for those who are overweight and think they will lose much more weight if they exercise: a study conducted by researchers at the University of Pittsburgh of 383 dieters showed that there is not a big difference if you join the calorie restriction in a sports program. After a year in which the calories consumed were between 1,200 and 1,800 per day, the average weight loss for the participants was 20 pounds (about 9 kilos), with no significant difference between those who had done 1.5 or 4 hours of exercise per week.


How reliable are commercial apps? In this case, the authors, researchers from Northwestern University in Chicago, compared the calories and nutrients attributed to 50 foods by two very popular apps in the United States, called CalorieKing and MyFitnessPal, with the official values ​​and found substantial reliability, with some exception and some conversion rigidity. There is still room for many improvements - they concluded - and it is important that the reference values ​​are always those established by research centers and governments, but the situation is not too bad.


Is the personalized approach better? Personalizing the diet does not seem to increase the confidence of those who follow it in their ability to eat better and less. Researchers from New York University analyzed data from 75 people who had been on a personalized diet for three months or less and saw no difference in the two groups, but the period may have been too short. The diet continues, and so does the study of the participants' reactions.