Researchers studied over 121,000 Chinese students to understand how their eating and exercise habits affect belly fat. They found that kids who drink sugary beverages and eat fried foods—even if they exercise a lot—have more belly fat than kids who avoid these foods. Surprisingly, kids who eat regular meals and more meat had less belly fat. The study suggests that what kids eat after exercising matters just as much as the exercise itself. Schools should teach students to make better food choices, especially after physical activity.

The Quick Take

  • What they studied: How different combinations of eating habits and exercise levels affect belly fat in school-age children
  • Who participated: Over 121,000 students aged 8-15 years old from rural areas across 115 counties in China, attending grades 3-9
  • Key finding: Kids who frequently drink sugary beverages and eat fried foods had significantly more belly fat, even when they exercised regularly. Kids who ate regular meals throughout the day had less belly fat.
  • What it means for you: Exercise alone may not prevent belly fat if kids are consuming sugary drinks and fried foods. Healthy eating habits—especially eating regular meals and limiting sugary drinks—appear to be equally important. This is particularly relevant for families in rural areas with limited nutrition education.

The Research Details

This was a large observational study where researchers measured 121,912 students’ height, weight, and waist size in the morning. They asked students about what they ate and how much they exercised using questionnaires. The researchers then used statistical methods to identify five different patterns of eating and exercise habits among the students. They examined which patterns were connected to having more belly fat, while accounting for other factors that might affect results like age and gender.

The researchers measured belly fat in two ways: by looking at waist circumference (how big around the waist is) and by calculating waist-to-height ratio (comparing waist size to how tall the student is). This dual approach helps ensure the findings are reliable.

This study design is important because it looks at real-world eating and exercise patterns that students actually follow, rather than testing one specific diet or exercise program. By studying such a large group of students across many counties, the results are more likely to apply to other students in similar situations. The study also identified five distinct lifestyle patterns, which helps explain that it’s not just about exercising or eating well—it’s about how these behaviors combine.

This study has several strengths: it included a very large number of students (over 121,000), used standardized measurement procedures for height and weight, and adjusted for other factors that might affect results. However, because it’s observational rather than experimental, we can’t say that sugary drinks definitely cause belly fat—only that they’re associated with it. The study was conducted in rural China, so results may not apply equally to urban areas or other countries with different food environments.

What the Results Show

The researchers identified five distinct eating and exercise patterns among students. About 16.6% to 20.6% of students had excess belly fat, depending on how it was measured. The most important finding was that students who frequently consumed sugary beverages and fried foods had 14% higher risk of belly fat compared to students who rarely consumed these foods—even if both groups exercised regularly. This suggests that exercise doesn’t fully protect against belly fat if students are eating unhealthy foods.

Interestingly, students who ate very little and didn’t exercise much actually had lower belly fat risk than expected. This may seem counterintuitive, but it likely reflects that these students simply consumed fewer calories overall. The study also found that students who ate regular meals throughout the day had significantly less belly fat than those with irregular eating patterns.

Students who ate more meat had less belly fat, which was unexpected. This may be because meat is more filling and helps students feel satisfied longer, reducing overall calorie intake. Students with daily frequent eating patterns (eating multiple times per day) also had lower belly fat risk, suggesting that regular, frequent small meals may be better than eating large amounts at once. These findings suggest that meal timing and frequency matter for belly fat, not just total calories consumed.

This study adds important nuance to existing research on exercise and weight. While previous studies have shown that exercise is important for health, this research emphasizes that what students eat—especially after exercising—is equally critical. The finding that sugary drinks and fried foods increase belly fat risk aligns with global nutrition research, but this is one of the first large studies to specifically examine how these foods interact with exercise patterns in school-age children.

This study only measured students at one point in time, so we can’t say whether the eating and exercise patterns caused the belly fat or if students with belly fat changed their habits. The study was conducted in rural China, so results may differ in cities or other countries with different food availability and cultural eating patterns. The study relied on students’ reports of what they ate and how much they exercised, which may not be completely accurate. Finally, the study couldn’t measure all factors that affect belly fat, such as sleep, stress, or genetics.

The Bottom Line

Schools should teach students to limit sugary drinks and fried foods, especially around exercise time (moderate confidence). Students should eat regular meals throughout the day rather than skipping meals (moderate confidence). Including protein-rich foods like meat in meals appears beneficial (moderate confidence). Exercise remains important, but shouldn’t be viewed as allowing students to eat unhealthy foods without consequences (high confidence).

This research is most relevant for parents and educators of school-age children (8-15 years old), particularly in rural areas with limited nutrition education. It’s especially important for families trying to prevent or reduce belly fat in their children. School administrators and nutrition programs should use this information to design better nutrition education. This may be less directly applicable to urban areas with different food environments or to adults, though the principles likely apply broadly.

Changes in belly fat don’t happen overnight. Students who improve their eating habits would likely see measurable changes in waist circumference within 2-3 months of consistent healthy eating. More significant changes would take 6-12 months. The benefits of regular meals and limiting sugary drinks may appear sooner in terms of energy levels and how clothes fit.

Want to Apply This Research?

  • Track daily sugary beverage intake (number of drinks per day) and fried food servings, alongside exercise minutes. Measure waist circumference weekly or monthly to monitor belly fat changes.
  • Set a specific goal like ‘drink zero sugary beverages on school days’ or ’eat three regular meals plus two healthy snacks daily.’ Use the app to log meals and drinks, and receive reminders to eat regular meals and choose water instead of sugary drinks.
  • Create a dashboard showing weekly trends in sugary drink consumption, meal frequency, and waist measurements. Set alerts when sugary drink intake exceeds goals, and celebrate weeks with consistent meal patterns and limited sugary beverages.

This research shows associations between eating patterns and belly fat in Chinese school children but does not prove that sugary drinks cause belly fat. Individual results vary based on genetics, overall health, and other lifestyle factors. Parents and caregivers should consult with a pediatrician or registered dietitian before making significant changes to a child’s diet or exercise routine, especially if the child has existing health conditions. This study was conducted in rural China and may not apply equally to all populations or geographic regions.