Researchers in Brazil studied what 1,379 schoolchildren ate at dinner and evening snacks to see if eating habits at night affected their weight. They found that kids who ate more meat, eggs, and seafood at dinner were more likely to be overweight. Interestingly, kids who drank more water at dinner and ate more dairy products or sugary drinks as evening snacks were less likely to be overweight. The study suggests that what and how much kids eat during evening meals might play a role in whether they develop weight problems, though scientists say more research is needed to fully understand this connection.

The Quick Take

  • What they studied: Whether the types and amounts of food kids eat at dinner and evening snacks are connected to being overweight
  • Who participated: 1,379 schoolchildren between ages 7 and 14 from Florianópolis, Brazil. About one-third of them were overweight.
  • Key finding: Kids who ate more protein foods like meat, eggs, and fish at dinner were 61% more likely to be overweight. However, kids who drank more water at dinner or ate more dairy products at evening snacks were less likely to be overweight.
  • What it means for you: Evening meals and snacks may matter for kids’ weight. Choosing water over sugary drinks and including dairy products in snacks might help, while limiting large portions of meat at dinner could be beneficial. However, this is just one study, so talk to a doctor before making major diet changes.

The Research Details

This was a cross-sectional study, which means researchers took a snapshot of kids’ eating habits and weight at one point in time, rather than following them over months or years. Researchers measured each child’s height and weight using standard methods, then calculated their Body Mass Index (BMI)—a number that shows whether someone’s weight is healthy for their height. Kids reported what they ate using an online questionnaire called Web-CAAFE. The researchers then used statistical tools to look for patterns between what kids ate at dinner and evening snacks and whether they were overweight.

This type of study is useful for spotting connections between diet and weight, but it can’t prove that one causes the other. It’s like noticing that people with umbrellas are wet—you can see they go together, but you can’t be sure if the umbrella caused the wetness or if the rain did.

Evening meals are important because kids eat a lot of their daily calories at dinner and snack time. Understanding which foods and drinks at these meals are linked to weight problems could help parents and schools make better food choices. This study focused specifically on evening eating, which many other studies overlook.

The study included a large number of children (1,379), which makes the findings more reliable. The researchers measured height and weight directly rather than relying on guesses. However, kids reported their own food intake, which might not be completely accurate—kids might forget what they ate or not remember portion sizes. Also, this study only looked at one city in Brazil, so results might be different in other places or countries.

What the Results Show

The most striking finding was about protein foods at dinner. Children who ate a higher percentage of their dinner calories from meat, eggs, and seafood were significantly more likely to be overweight. Specifically, kids in the highest group had a 61% greater chance of being overweight compared to those eating less of these foods.

Surprisingly, water consumption at dinner showed the opposite pattern. Kids who drank more water at dinner were less likely to be overweight—about 33% less likely. This makes sense because water has no calories and might replace sugary drinks.

At evening snack time, two things stood out. Kids who ate more dairy products (like yogurt or cheese) were about 39% less likely to be overweight. Similarly, kids who drank more sugary drinks at evening snack were about 33% less likely to be overweight, which seems counterintuitive but might reflect other eating patterns not captured in this study.

The study found that overall, about 34% of the children studied were overweight, which is a significant portion. The researchers looked at different food groups separately, which helped them identify specific foods and drinks connected to weight. The fact that water and dairy products showed protective effects suggests that what kids drink and snack on matters just as much as main meals.

Previous research has shown that eating late at night and consuming high-calorie foods can contribute to weight gain. This study adds to that knowledge by specifically looking at Brazilian children and identifying which foods at evening meals matter most. The finding about water is consistent with other research showing that replacing sugary drinks with water helps with weight management. However, the finding about sugary drinks at snack time being protective is unusual and suggests there may be other factors the study didn’t measure.

This study has several important limitations. First, it’s a snapshot in time—researchers can’t prove that eating meat at dinner causes weight gain, only that they happen together. Second, children reported their own food intake, which might not be completely accurate. Third, the study only included children from one Brazilian city, so results might not apply to children in other countries or regions with different food cultures. Fourth, the researchers didn’t measure physical activity, which is crucial for weight management. Finally, the unexpected finding about sugary drinks suggests the study might be missing important information about how kids’ overall diets work together.

The Bottom Line

Based on this research (with moderate confidence): Encourage kids to drink water instead of sugary drinks at dinner. Include dairy products in evening snacks. Consider portion sizes of meat, eggs, and seafood at dinner—they’re nutritious but eating too much might contribute to weight gain. These changes should be part of a broader healthy lifestyle that includes physical activity and balanced meals throughout the day.

Parents and caregivers of school-age children should pay attention to these findings. Kids who are already overweight or at risk might especially benefit from these changes. Teachers and school lunch planners could use this information to improve evening meal options. However, these findings are most relevant to children in Brazil and similar settings—kids in other countries might have different results.

Changes in eating habits take time to show results. Most experts suggest giving dietary changes at least 2-4 weeks before expecting to see differences in weight or how kids feel. Healthy weight changes happen slowly—about 1-2 pounds per month is typical and healthy for growing children.

Want to Apply This Research?

  • Track the percentage of dinner calories from protein foods (meat, eggs, fish) versus other food groups. Also track daily water intake at dinner and dairy product consumption at evening snacks. Aim to increase water and dairy while moderating protein portions.
  • Set a specific goal: ‘Replace one sugary drink with water at dinner this week’ or ‘Add one dairy product to evening snack.’ Use the app to log these swaps and celebrate small wins to build momentum.
  • Weekly check-ins on water intake and dairy consumption at evening meals. Monthly tracking of overall eating patterns at dinner and snack time. Connect this to weight tracking (if appropriate) to see if changes correlate with health improvements over 8-12 weeks.

This research suggests associations between evening eating patterns and childhood weight, but does not prove cause-and-effect relationships. Individual results vary based on overall diet, physical activity, genetics, and other health factors. Before making significant changes to a child’s diet, consult with a pediatrician or registered dietitian, especially if the child has existing health conditions or dietary restrictions. This information is for educational purposes and should not replace professional medical advice.