Study relates the double burden of obesity and malnutrition in teenagers

Even obese, Brazilian teenagers still have traits of malnutrition, as shown by a study published in the most recent edition of PLOS One magazine. Researchers found both conditions especially in public school students, who showed an increase in overweight rates in recent years.

The investigation, carried out by researchers from the School of Nutrition of the Federal University of Bahia (UFBA) and the Center for the Integration of Data and Knowledge for Health (Cidacs / Fiocruz Bahia), is the first in Brazil to monitor socioeconomic factors associated with malnutrition and obesity. “There are few studies that bring these nutritional outcomes presented simultaneously,” emphasized researcher Júlia Uzêda.

The double burden of poor nutrition, when malnutrition and obesity occur simultaneously, affects a small portion of the students (less than 1%). However, the condition demonstrates that an improvement in the socioeconomic conditions of life is not always accompanied by a better nutritional quality. 

“In recent decades, even in developing economies such as Brazil, seemingly antagonistic forms of poor nutrition, like malnutrition and obesity, have come to coexist in the same individual. The double burden is a rare and yet little investigated event, and this is the first study to evaluate its prevalence and associated socioeconomic factors in a subgroup of the Brazilian population,” explains a researcher from Cidacs, Natanael Silva, also a member of the study.

Overweight

According to the researchers, there was an increase in overweight among teenagers of all socioeconomic levels and, at the same time, malnutrition also appears in these students, revealed by their short stature. According to the study, teenagers from private schools are more likely to develop overweight compared to public school students. However, Uzêda explains, “this difference between groups was gradually reduced.”  Between 2009 and 2015, while the index of overweight teenagers in private schools remained unchanged (28.7%), the rate in public schools increased from 19% to 23.1%. 

The research used data from the first (2009) and the most recent (2015) editions of the National Survey of School Health (PeNSE), a survey that investigates chronic noncommunicable diseases among Brazilian school teenagers. The group compared the nutritional indexes of students aged 13 to 17 years, separating those who are only overweight or have short stature and those who present both conditions.

Numbers

For this investigation, socioeconomic information from these teenagers was selected, such as the mother's level of education, race, gender and type of school unit. In 2009, 31,823 girls and 27,814 boys responded to Pense. In 2015, Pense brought 5,317 girls and 5,453 boys. At the first moment, 140 girls (0.5%) featured both overweight and malnutrition, while among boys this rate was 0.3% (74 individuals).

Still in 2009, when the group that presented the two health outcomes was separated, regardless of sex, and differentiating between public and private school students, this simultaneity appeared in 29 private school students (0.2%) against 185 (0.4%) public school students. That is, the double burden is more significant among public school students. In 2015, the double burden rate increased among private school students while public school students remained stable - 7 students from private schools (0.3%) and 30 from public schools (0.4%) were found to have this condition. And with regard to gender, girls are still the majority: 0.4% (20) featured the condition against 0.3% (17) of boys.

Factors

“These findings show that obesity has grown and is increasingly reaching the socially and economically disadvantaged population,” says researcher Natanael Silva. “The increase in overweight in this group is probably due to an improvement in social and economic conditions and especially to factors such as increased consumption of ultra-processed food and more exposure to obesogenic environments.”

One of the factors that was associated with the double burden of poor nutrition is the level of education of the students’ mothers. The children of women who completed primary education showed better nutrition indexes, presenting half the double burden rate than students whose mothers did not complete this stage.

Uzêda stresses that “there are factors that have not been analyzed in this study, such as food consumption and, especially, the quality of food eaten”, but that the information found may already serve for public policies to focus on the quality of nutrition.