Researchers compared what Brazilian adults ate in two different time periods (2008-2009 and 2017-2018) to see how eating habits changed between generations. They found that younger adults, especially those with lower incomes, eat more ultra-processed foods like packaged snacks and fast food compared to older generations. Interestingly, younger people overall eat fewer total calories than older people did at the same age. This study shows that money matters when it comes to food choices—poorer young adults rely more on cheap, processed foods than wealthier young adults do.

The Quick Take

  • What they studied: Whether young Brazilian adults eat differently than older generations, and whether money affects what type of food they choose
  • Who participated: Over 61,000 Brazilian adults of different ages, tracked across two national food surveys about 10 years apart. The study compared people born from 1928 to 1988, looking at their eating patterns when they were surveyed
  • Key finding: Young adults (ages 20-39) with lower incomes in 2017-2018 ate significantly more ultra-processed foods compared to older generations at the same age. However, this pattern only appeared in lower-income groups, not among wealthier young adults
  • What it means for you: If you’re a young adult with limited money, you may be eating more processed foods than previous generations did—not because of personal choice, but because healthy food is expensive. This suggests that improving food access and affordability for lower-income young people could help improve their diets

The Research Details

Researchers used data from two large national surveys of what Brazilians eat, conducted about 10 years apart. They looked at the same age groups in both surveys to compare how eating habits changed over time. For example, they compared 30-year-olds from 2008-2009 with 30-year-olds from 2017-2018. They organized all foods into categories based on how processed they are: unprocessed foods (like rice and beans), minimally processed foods (like canned vegetables), processed foods (like canned soups), and ultra-processed foods (like packaged snacks and fast food). They then used math models to see if income level affected which types of foods people ate.

This approach is strong because it uses real data from huge numbers of people rather than relying on small groups or guesses. By comparing the same age groups across two time periods, researchers can see how eating habits are actually changing in society, not just differences between age groups at one point in time. Looking at income separately helps explain why changes happen—it shows that money is a key factor in food choices

This study is reliable because it used official national surveys with tens of thousands of participants, making the results representative of Brazil’s population. The researchers used a standard system (NOVA classification) to categorize foods, which other scientists also use. However, the study only looked at Brazil, so results may not apply to other countries. The surveys asked people to remember what they ate, which can sometimes be inaccurate

What the Results Show

The main finding was that younger generations eat fewer total calories than older generations did at the same age—this was true for both men and women across all age groups. When researchers looked at the 2017-2018 data specifically, they found that young adults (ages 20-39) from lower-income families ate more ultra-processed foods compared to older generations from lower-income families. This difference was striking and statistically significant, meaning it wasn’t due to chance. Interestingly, this pattern did NOT appear in higher-income groups—wealthy young adults didn’t eat significantly more processed foods than wealthy older adults did. This tells us that income is the key factor driving the difference in processed food consumption among younger people.

When researchers looked at the overall breakdown of calories from different food types, they found that the percentage of calories from each category (unprocessed, minimally processed, processed, and ultra-processed) was similar across generations. This means that while younger, lower-income adults eat more ultra-processed foods, they’re not necessarily eating them instead of other foods—the overall diet structure remained similar. The reduction in total calories among younger generations happened across all income levels and age groups, suggesting this is a broad trend affecting all young Brazilians

Previous research has shown that ultra-processed foods are becoming more common in many countries, but this study adds important context by showing that this trend is strongest among lower-income young people. Other studies have found that processed foods are often cheaper than fresh foods, which aligns with this study’s findings. The overall calorie reduction in younger generations matches trends seen in other developed and developing countries, where younger adults tend to eat less than previous generations did

The study only included data from Brazil, so these findings may not apply to other countries with different food systems and economies. The surveys asked people to remember what they ate, which can be inaccurate—people might forget foods or misremember portion sizes. The study couldn’t prove that income directly causes higher processed food consumption; it only shows they’re connected. The sample size note in the metadata appears to be an error (showing 36 instead of the actual 61,804 participants), which suggests there may be data entry issues to verify

The Bottom Line

If you’re a young adult with limited income, try to include at least one unprocessed or minimally processed food in each meal (like beans, rice, or fresh vegetables) even if you also eat some processed foods. This doesn’t require perfection—small improvements matter. For policymakers and communities: this research suggests that making fresh, healthy foods more affordable and accessible for lower-income young people could significantly improve their diets. The confidence level for these recommendations is moderate—the study shows a clear pattern, but individual circumstances vary

Young adults (ages 20-39) with lower incomes should pay attention to this research, as it directly describes their eating patterns. Parents and educators should care because this affects the next generation’s health. Policymakers and public health officials should prioritize making healthy foods affordable for young, lower-income people. Wealthier young adults may find this less directly relevant to their own situation, though it’s still important for understanding broader health inequalities. People in countries outside Brazil should note that while the specific numbers may differ, the underlying pattern (income affecting processed food consumption) likely applies elsewhere too

Changes in eating habits typically take weeks to months to notice in terms of how you feel (more energy, better digestion). Health benefits like improved weight management or better blood sugar control may take 2-3 months to become apparent. Long-term health improvements from eating less processed food can take 6-12 months or longer to measure

Want to Apply This Research?

  • Track the number of ultra-processed foods you eat each day and set a goal to reduce them by 10-20% each week. Log specific items like packaged snacks, fast food, and sugary drinks. Compare your weekly average to see if you’re making progress
  • Use the app to find and save recipes for simple, affordable meals using unprocessed ingredients (rice, beans, eggs, seasonal vegetables). Set reminders to meal plan on weekends so you’re prepared with healthier options. Use the app’s budget feature to compare the cost of making meals at home versus buying processed alternatives
  • Check your processed food consumption weekly and adjust your shopping list accordingly. Track not just what you eat, but also how you feel—energy levels, digestion, and mood—to connect food choices with wellbeing. Set monthly goals to gradually shift your diet toward more whole foods, celebrating small wins along the way

This research describes patterns in Brazilian food consumption and should not be considered medical advice. Individual dietary needs vary based on age, health conditions, activity level, and personal circumstances. If you have specific health concerns or dietary restrictions, consult with a healthcare provider or registered dietitian. This study shows associations between income and processed food consumption but does not prove that processed foods directly cause health problems in all individuals. The findings are specific to Brazil and may not apply to other countries or populations. Always discuss major dietary changes with a healthcare professional, especially if you have existing health conditions or take medications that interact with food