Researchers in Portugal studied what over 2,200 adults eat and how their food choices affect both their health and the environment. They found that people who eat traditional, home-cooked meals made with less processed foods have better overall diet quality than those who eat a lot of fast food and restaurant meals. Interestingly, younger and more educated people were more likely to eat unhealthy convenience foods. The study suggests that cooking at home and eating less processed food could help people stay healthier while also being better for the planet.

The Quick Take

  • What they studied: How different eating patterns in Portugal affect both personal health and environmental sustainability, and whether where and how food is prepared matters
  • Who participated: 2,287 Portuguese adults ranging from 18 to 84 years old, representing a mix of ages, education levels, and living situations from a national food survey conducted in 2015-2016
  • Key finding: People who eat traditional home-cooked meals or follow diets focused on health concerns had significantly better overall diet sustainability scores compared to those eating unhealthy, processed foods. Restaurant and takeout meals were linked to lower sustainability scores.
  • What it means for you: Cooking meals at home using whole foods instead of eating restaurant food or ultra-processed items may help you feel better and reduce your environmental impact. This appears especially important for younger adults who tend to rely more on convenience foods.

The Research Details

Researchers used information from a large national food survey in Portugal that tracked what people ate over several years (2015-2016). They looked at 2,287 adults and grouped them based on two things: what types of foods they ate (traditional foods, health-conscious choices, or unhealthy processed foods) and where their food came from (home-cooked, prepared by family, store-bought, or restaurant meals). They then scored each person’s diet using a special sustainability score that measured health, environmental impact, cost, and cultural factors. The researchers used statistical analysis to find connections between eating patterns and sustainability, while accounting for differences in age, sex, education, and how much people ate overall.

Understanding how food choices affect both personal health and the planet is increasingly important. This study is valuable because it looks at real eating patterns in a large population rather than just asking people to follow a specific diet. By examining both what people eat and where it comes from, the research provides practical insights about everyday food decisions.

This study used data from an official national survey, which means the information is reliable and representative of the Portuguese population. The large sample size of over 2,200 people strengthens the findings. However, because this is a snapshot in time rather than following people over years, we can see associations but not prove that one thing directly causes another. The study adjusted for important factors like age and education that could influence results.

What the Results Show

The most important finding was that traditional eating patterns and health-conscious diets scored significantly higher on sustainability measures compared to unhealthy, processed-food-heavy diets. People eating traditional foods scored about 1.27 points higher on the sustainability scale, while those focused on health concerns scored 1.60 points higher. This difference was statistically significant, meaning it’s unlikely to be due to chance.

When looking at where food came from, meals prepared at home by the person eating them had the best sustainability scores. In contrast, people who regularly ate restaurant and takeout food had noticeably lower sustainability scores—about 0.76 points lower. Interestingly, there was no significant difference between home-cooked meals and food prepared at home by family members or friends.

The study also revealed important demographic patterns: younger adults, people living in cities, and more educated individuals were more likely to follow unhealthy eating patterns and rely on restaurant meals. This was somewhat surprising, as education is often associated with healthier choices, but in this case, educated younger urbanites were choosing convenience over sustainability.

The research highlighted that the sustainability score considers multiple dimensions beyond just nutrition—it includes environmental impact, cost, and cultural factors. This means that traditional diets weren’t just healthier; they were also better for the planet and often more affordable. The study also showed that how food is prepared matters almost as much as what food is chosen, suggesting that the cooking method and location are important factors in overall diet quality.

This research aligns with growing evidence that ultra-processed foods are linked to health problems and environmental concerns. Previous studies have shown that traditional Mediterranean and plant-based diets are sustainable, and this Portuguese study confirms that traditional eating patterns remain beneficial. The finding that restaurant meals have lower sustainability scores matches other research showing that eating out is often associated with higher calorie intake and more processed ingredients. However, this study uniquely examines sustainability across multiple dimensions in a real-world population.

Because this study captured eating patterns at one point in time rather than following people over years, we cannot say that changing to home-cooked meals will definitely improve health—only that these patterns are associated. The data is from 2015-2016, so eating habits may have changed since then, especially with increased food delivery services. The study focused on Portugal, so results may not apply exactly to other countries with different food cultures and availability. Additionally, the study relied on people reporting what they ate, which can sometimes be inaccurate.

The Bottom Line

Based on this research, consider cooking more meals at home using whole, minimally processed foods rather than relying on restaurant meals and convenience foods (moderate confidence level). This appears to benefit both personal health and environmental sustainability. For younger adults and urban dwellers especially, being intentional about home cooking may provide significant benefits (moderate confidence level).

Everyone can benefit from these findings, but they’re particularly relevant for younger adults and city dwellers who tend to rely more on restaurant and processed foods. People concerned about environmental impact alongside personal health should especially consider these recommendations. Those with limited budgets may find that home cooking is also more economical. However, people with limited cooking facilities, time constraints, or disabilities that make cooking difficult should focus on making the best choices available to them rather than feeling pressured to cook everything from scratch.

Changes in how you feel and your energy levels may appear within a few weeks of eating more home-cooked meals. Measurable health improvements like better digestion or weight changes typically take 4-8 weeks. Environmental and economic benefits accumulate over time as you establish new habits.

Want to Apply This Research?

  • Track the number of home-cooked meals versus restaurant/takeout meals per week, aiming to increase home-cooked meals from your current baseline by 20% each month
  • Set a weekly meal-prep reminder to prepare 2-3 simple home-cooked meals in advance, making it easier to choose home food over restaurant options during busy weekdays
  • Log each meal’s source (home-cooked, restaurant, store-bought) and rate your energy levels and digestion daily to correlate eating patterns with how you feel over 8-12 weeks

This research shows associations between eating patterns and diet sustainability but does not prove that changing your diet will directly cause health improvements. Individual results vary based on overall lifestyle, genetics, and existing health conditions. If you have specific health concerns, food allergies, or dietary restrictions, consult with a healthcare provider or registered dietitian before making significant dietary changes. This study reflects Portuguese eating patterns and may not apply equally to all populations or regions.