Obesity risk is 45% higher among teenagers who eat a lot of ultra-processed foods

Based on data from 3,587 adolescents aged 12 to 19 years who participated in the US National Health and Nutrition Survey, researchers from the University of São Paulo (USP) calculated how much the consumption of ultra-processed foods impacts the risk of obesity.

In the study, young people were divided into three groups according to the amount ingested of these products. When comparing those who ate the most ultra-processed foods (on average 64% of the total grams of the diet) with those who ate the least (18.5% on average), it was observed that those in the first group were 45% more likely to be obese, 52 % more chance of abdominal obesity (fat located in the belly) and –the most worrying data– 63% more chance of visceral obesity (accumulation of fat between the organs), which is highly related to the development of hypertension, coronary artery disease, diabetes type 2, dyslipidemia and increased risk of mortality.

The full results of the research, supported by Fapesp, were published in the Journal of the Academy of Nutrition and Dietetics.

“The scientific evidence has become quite solid regarding the negative role of ultra-processed foods in the obesity pandemic. This is very well demonstrated for adults. of the diet of North American adolescents –, but the results regarding the association between dietary patterns based on ultra-processed foods and health outcomes, including obesity, were scarce and inconsistent”, explains Daniela Neri, the first author of the article and a member of the Center for Epidemiological Research in Nutrition and Health (Nupens) of the Faculty of Public Health at USP.

Context

Coordinated by Professor Carlos Augusto Monteiro, the Nupens team was a pioneer in associating changes in industrial food processing with the obesity pandemic, which began in the United States in the 1980s and, in the 21st century, affected most countries in the world. .

Based on this hypothesis, the group developed a classification for foods, called Nova, based on the level of industrial processing. The work supported the recommendations of the Food Guide for the Brazilian Population launched in 2014, which recommends prioritizing culinary preparations with in natura or minimally processed foods and avoiding ultra-processed foods – a category that can include everything from soft drinks, stuffed cookies and packaged snacks to even a seemingly innocent whole grain bread.

“In general, ultra-processed foods and beverages contain chemical additives – such as dyes, flavorings, emulsifiers and thickeners – that seek to improve the sensory characteristics of the product. Many of them have high energy density and high levels of sugar and fat, which directly contributes for weight gain.

But even low-calorie foods, such as diet soda, can favor the development of obesity in ways that go beyond nutritional composition. For example, interfering with the body’s satiety signaling or modifying the gut microbiota”, explains Neri.

Methodology

In the recently published research, the adolescents’ diet was evaluated using a methodology known as the 24-hour Food Record, which consists of obtaining information on the types and amounts of all foods and beverages ingested on the day before the interview. , as well as the times and places of consumption of meals. Most of the participants included in the analysis (86%) underwent two interviews of the type, with an interval of two weeks between them.

Based on this recall, the young people were divided into three groups. In the first were those who consumed up to 29% of the total grams of the diet in ultra-processed foods. In the second, those for whom this percentage varied between 29% and 47% and, in the last tertile, those with values ​​above 48%.

Anthropometric data of the participants, including weight, height and waist circumference, were also evaluated. These indices were evaluated for age and sex, according to the US Centers for Disease Control (CDC) growth pattern.

“The risk of total obesity was estimated based on BMI, which is calculated by dividing weight [em quilos] by the height squared [em metros]. To assess abdominal obesity, we used the measurement of abdominal circumference. And a lesser-known parameter, which is the sagittal abdominal diameter, was used as a proxy [valor representativo] of visceral obesity”, says Neri.

As the researcher explains, the sagittal abdominal diameter is an indirect and non-invasive way of measuring the amount of fat between the organs. “The individual lies down on the stretcher and, with a kind of ruler [paquímetro], the distance from the lower back to the navel region is measured, so that the softer subcutaneous fat falls to the sides and the more rigid visceral fat remains in place. In this way, any measurement errors that could be caused by folds in the waist region are avoided.”

All data evaluated in the USP survey were drawn from the National Health and Nutrition Examination Survey (Nhanes) – the continuously conducted national health and nutrition survey in the United States. It is a public database covering a nationally representative sample of the US population.

In the study, information collected between 2011 and 2016 was used. According to Neri, the conclusions can be extrapolated to young Brazilians, who are also exposed from an early age to ultra-processed foods, albeit to a lesser extent.

“In Brazil, there is no survey that provides, at the same time, information on food consumption of adolescents and anthropometric data collected in face-to-face assessments. This type of nutritional survey is expensive and requires continuous funding. In the country there are some similar initiatives, however, simpler”, comments Neri.

In Vigitel, which is the national survey conducted annually by the Ministry of Health to monitor risk and protective factors for chronic diseases, for example, data collection is done by telephone and only with people over 18 years of age.

The most recent data from this survey, released in January this year by the Institute of Studies for Health Policies (IEPS), indicate that the obesity rate in the adult population of Brazil increased from 11.8% in 2006 to 21.5% in 2020. , that is, practically doubled.

The Household Budget Survey (POF) of the Brazilian Institute of Geography and Statistics (IBGE) provides data on the food consumption of adolescents and adults in the country, but does not contain information on the health status of those surveyed.

According to the most recent edition of the POF, carried out between 2017 and 2018, more than half (53.4%) of the calories consumed by Brazilians come from fresh foods (vegetables, fruits, meats, milk, etc.) or minimally processed foods (grains and flours, for example), 15.6% from processed culinary ingredients (such as salt, sugar and olive oil), 11.3% from processed foods (cheese, artisan breads, preserved fruits and vegetables) and 19.7% from ultra-processed foods .

Among the adolescents analyzed in the POF, the proportion of ultra-processed foods represents 27% of total daily calories, while among adults aged 60 years and over this percentage is 15.1%.

comparisons

In another study conducted at Nupens and published in the journal Obesity Reviews, researchers compared data on the dietary pattern of adolescents from the 2017-2018 POF with similar information from seven other countries: Argentina, Australia, Chile, Colombia, Mexico, the United States and United Kingdom.

The share of ultra-processed foods in young people’s diets varied greatly between nations – being lowest in Colombia (19% of dietary calories) and Brazil (27%) and highest among the British (68%) and North Americans (66% of the total). ). Despite the discrepancy in consumption, the impact on the quality of the diet was very similar in all populations evaluated, says Neri to Agência Fapesp.

“In this study, young people were also divided into groups according to the consumption of ultra-processed foods. And we observed that, as the participation of these products increases, there is a worsening in the quality of the diet, that is, the energy density and the levels of sugar. On the other hand, fiber is reduced. The negative effect is very similar in all countries, regardless of the proportion of ultra-processed products, the region or the culture.”

Although rice and beans are still the mainstay of Brazilian food, the researcher points out, a survey released last year by the Ministry of Health revealed that consumption of ultra-processed foods is common in the country even among children under 5 years old: over 80. % of individuals in this age group make regular use.

“Ingestion of these products takes away the space of in natura or minimally processed food at a stage in which eating habits are being formed”, warns Neri. “This exposure of children and adolescents to these obesogenic foods represents a real programming for future health problems. It is really worrying.”

For the researcher, controlling this exposure is beyond the ability of families, since it would be necessary to remodel the entire current food system.

“In addition to raising consumer awareness, it is necessary to act on several fronts through public policies. There are different possible strategies, such as restricting advertising, especially for children, and increasing the taxation of these products, while expanding access to fresh foods. Another fundamental measure concerns labels, which should provide clearer information to guide consumers’ food choices”, says Neri.

The studies published by the Nupens team received funding from Fapesp through five projects (15/14900-9, 16/25853-4, 18/17972-9, 19/22278-7 and 16/14302-7).