Diet of Brazilian population is increasingly standardized
August 31, 2016
By Elton Alisson | Agência FAPESP – The regular diet of people living in isolated parts of the Brazilian Amazon and in the Northeast and Center-West regions, as well as those in fishing communities on the northern coast of São Paulo State, is increasingly similar to the eating habits of city dwellers.
Riverine communities in the Amazon used to eat locally produced goods, such as fish with cassava flour, for example. Now, their diet tends to consist mainly of processed foods, such as canned meat and vegetables, or frozen chicken produced in the industrialized South and Southeast.
The change has been detected in a number of studies performed in recent years with FAPESP’s support by researchers at the University of São Paulo’s Center for Nuclear Energy in Agriculture (CENA-USP) and Luiz de Queiroz College of Agriculture (ESALQ), in collaboration with colleagues at the University of Brasília (UnB), the Federal University of Acre (UFAC) and the Rio Grande do Norte State University (UERN).
Some of the results of their studies have been published in Ecology of Food & Nutrition and in Environment, Development & Sustainability. They were also presented during the “School of Advanced Science on Nitrogen Cycling, Environmental Sustainability & Climate Change” held in August in São Pedro, São Paulo State, Brazil.
Organized by CENA-USP and the Inter-American Institute for Global Change Research (IAI), the event was funded by FAPESP under its São Paulo School of Advanced Science Program (SPSAS).
One hundred graduate students, 50 from Brazil and 50 from other countries, were selected to take part in the ten-day course of lectures and discussions on the unequal distribution of nitrogen in the world and its impact on environmental sustainability in the context of climate change.
“Generally speaking, the findings show dietary homogenization throughout Brazil,” said Gabriela Bielefeld Nardoto, a professor at UnB and one of the authors of the studies.
“Rural populations in different regions, even when isolated, have increasingly adopted a ‘supermarket diet’ of processed and ultra-processed foods,” Nardoto told Agência FAPESP.
Nardoto began studying the subject in 2002. Her PhD research, supported by a grant from FAPESP, focused on the dietary roles of grain legume pulses and seeds in two tropical ecosystems (the Amazon and the Cerrado) via an analysis of fingernail carbon and nitrogen isotopes. Participants were also interviewed to identify everything they had eaten in the previous 24 hours (read more at revistapesquisa.fapesp.br/en/2006/07/01/diet-on-the-tips-of-the-fingers).
Initial studies conducted in 2002 showed that the inhabitants of cities such as Piracicaba (São Paulo State, in the Southeast) and Santarém (Pará State, in the North) had similar proportions of carbon from C4 plants in their diets.
C4 plants, which include sugarcane, corn and pasture grass, are characterized by a type of photosynthesis that has a supplementary method of CO2 uptake in which a 4-carbon molecule is formed instead of the two 3-carbon molecules that appear in the more widespread C3 process.
The same research showed that the diets of small rural communities 50-80 km from Santarém were strikingly different from those of people living in Belém, the capital of Pará.
To investigate whether comparable dietary differences between town and country could be found in other parts of the Amazon region, the researchers performed a more detailed study in the period 2007-2010 as part of a project supported by FAPESP and led by Luiz Antonio Martinelli, affiliated with CENA-USP.
The study compared the diets of people living in Manaus, the capital of Amazonas State, and Tefé, a medium-sized town in the same state approximately 600 km from the capital, with those of rainforest dwellers living on the banks of the Solimões, or Upper Amazon River, who for centuries had derived their protein mainly from fish.
The researchers also investigated the eating habits of artisanal fishing communities along the Rio-Santos Highway near Ubatuba, a coastal city in São Paulo State, and people living in poor suburbs of the city at the foot of the Serra do Mar escarpment.
The findings from the studies showed that the diets of all these different populations were very similar whether they lived in large cities, medium or small towns, or rural areas.
Based on an analysis of fingernail isotopes, the researchers failed to detect differences between the diets of fishing communities or low-income inhabitants of Ubatuba and lower- and middle-income households in Piracicaba.
“These populations have all taken the supermarket diet completely on board,” Nardoto said. “The fishermen of Ubatuba, for example, use part of the proceeds of their catch to buy frozen chicken in the city center.”
Locally produced food still matters to rural communities in the Amazon, the researchers found, but even so these country folk are giving up their traditional diet for processed foods such as sausages, fizzy drinks and cookies, as well as the ubiquitous frozen chicken (read more at revistapesquisa.fapesp.br/en/2011/07/01/chickens-along-the-river-solimoes/?cat=science).
“Our hypothesis was that rural communities a long way away from urban centers would have maintained their diet of fish with cassava flour, but that’s not what we found along the Solimões,” Nardoto said.
The diets of riverine communities with access to electricity and diesel oil for boats closely resembled the eating habits of city dwellers, who have long performed all their shopping for food at the supermarket.
These communities tend to eat fresh fish with cassava flour only for lunch, according to Nardoto. “Consciously or not, they’ve kept up this midday meal habit but prefer processed and ultra-processed foods for breakfast and the evening meal,” she said.
To find out whether the growing resemblance between the diets of rural and urban populations they observed in São Paulo State was also the case in other parts of Brazil, the researchers studied four groups of people living in Rio Grande do Norte State in the Northeast region – two in the countryside outside Mossoró, the second-largest city in the state, an urban community in the city, and a fishing community on the Ponta do Tubarão Sustainable Development Reserve approximately 170 km from Natal, the state capital.
Their analysis of fingernail samples showed similar carbon and nitrogen stable isotope ratios in all four groups. “We thought there might be a difference in the diets of people living in the hinterland, in the city and on the coast, but they all had the same isotope signature,” Nardoto said. “Their eating habits closely resembled those we observed in the North and Center-West regions, and in São Paulo State.”
A recent study conducted by ESALQ’s Rodrigo de Jesus Silva through a doctoral scholarship provided by FAPESP analyzed changes in the diet of the Kalunga, descendants of runaway African slaves (maroons), in several communities living on protected land in the Chapada dos Veadeiros National Park, Goiás State.
He found that communities with easier access to road transportation had already adopted a supermarket diet, whereas those located in more remote areas not near a road still preferred food produced in the region. “These are among the only known rural communities where traditional dietary habits still prevail,” Nardoto said.
Simplification of sources
According to Nardoto, dietary homogenization due to factors such as urbanization, improving social conditions leading to lifestyle changes, and the replacement of local produce by processed foods has simplified food sources and fueled a change from C3 to C4 crop production.
The traditional diet of Brazilians, based on food derived from C3 crops such as rice and dry beans, is gradually being replaced by food derived from C4 crops such as corn and soybeans, found in various types of animal feed, as well as sugarcane.
“C4 foods aren’t unhealthy,” Nardoto said. “The problem is how they’re processed. They contain high levels of fat, salt and sugar, which contribute to a growing incidence of obesity and cardiovascular disease.”
Loss of dietary identity in rural communities can also have an impact on environmental conservation, she added.
“As these communities lose their dietary identity, they also eventually lose their link to the local landscape. If they no longer need to fish for food, the river ceases to be a food source and becomes a mere means of transportation,” she said.
The article “Food insecurity in urban and rural areas in Central Brazil: transition from locally produced foods to processed items” (doi: 10.1080/03670244.2016.1188090) by Livia Penna Firme Rodrigues et al. can be retrieved by subscribers to Ecology of Food & Nutrition at tandfonline.com/doi/full/10.1080/03670244.2016.1188090.
The article “Factors influencing the food transition in riverine communities in the Brazilian Amazon” (doi: 10.1007/s10668-016-9783-x) by Rodrigo de Jesus Silva et al., published in Environment, Development and Sustainability, can be retrieved from link.springer.com/article/10.1007/s10668-016-9783-x.
Agência FAPESP licenses news reports under Creative Commons license CC-BY-NC-ND so that they can be republished free of charge and in a straightforward manner by other digital media or by print media. The name of the author or reporter (when applied) must be cited, as must the source (Agência FAPESP). Using the button HTML below ensures compliance with the rules described in Agência FAPESP’s Digital Content Republication Policy.