Researchers studied over 1,000 children ages 5-9 to understand how eating habits and lifestyle affect their blood vessels and blood pressure. They found that children who ate lots of junk food like chips, sweets, and fast food had weaker blood vessels, even at this young age. Interestingly, children with normal blood pressure showed different patterns than those with high blood pressure. The study suggests that unhealthy eating habits can damage blood vessels starting in early childhood, which could lead to heart problems later in life. This research highlights how important it is for kids to eat healthy foods early on.

The Quick Take

  • What they studied: How different eating habits and lifestyle factors affect blood vessel health in young children, and whether these patterns differ between kids with normal and high blood pressure
  • Who participated: 1,043 children between ages 5 and 9 years old from South Africa, with measurements of their weight, fitness level, diet, blood pressure, and blood vessel function
  • Key finding: Children who regularly ate junk foods (chips, sweets, fast food, cookies, and cake) had narrower blood vessels and weaker blood vessel function, especially those with high blood pressure. This damage was visible even in young children
  • What it means for you: Encouraging children to eat healthy foods like fruits, vegetables, and lean meats instead of junk food may help protect their blood vessels and prevent high blood pressure problems later in life. The earlier healthy eating habits start, the better

The Research Details

Researchers measured over 1,000 children between ages 5 and 9, looking at what they ate, how fit they were, their weight, and their blood pressure. They also used special equipment to look at the tiny blood vessels in the children’s eyes and measured how stiff their major blood vessels were. The researchers then grouped the children based on whether they had normal or high blood pressure, and looked for patterns in their eating habits and lifestyle. They used a statistical method to identify which foods and lifestyle factors tended to go together.

By studying children this young, researchers can see how early damage to blood vessels begins, before serious heart problems develop. Understanding these patterns helps doctors and parents know which lifestyle changes matter most for protecting children’s hearts. This approach of looking at multiple factors together (like diet, weight, and fitness) gives a more complete picture than studying just one thing

This study measured actual blood vessel health using specialized equipment rather than just asking questions, which makes the results more reliable. The large number of children studied (over 1,000) makes the findings more trustworthy. However, because this is a snapshot in time rather than following children over years, we can’t be completely certain that junk food causes the blood vessel damage—only that they go together

What the Results Show

The researchers found three main patterns of risk factors. The first pattern included junk foods (chips, sweets, fast food, cookies, and cake). The second pattern included healthy foods (fruits, meat, milk) and family income level. The third pattern included weight and blood pressure measurements. Interestingly, these patterns showed up differently in children with normal blood pressure versus those with high blood pressure. In children with normal blood pressure, the junk food pattern was less common, and the weight/blood pressure pattern was more important. In children with high blood pressure, the junk food pattern was more common and more strongly linked to damaged blood vessels. The blood vessel damage was measured by looking at the tiny vessels in the eye and checking how stiff the major blood vessels were. Children eating more junk food had narrower eye blood vessels and stiffer major blood vessels, which are signs of damage.

Children with high blood pressure showed different relationships between diet and blood vessel health compared to those with normal blood pressure. In the normal blood pressure group, weight and blood pressure measurements were the strongest predictors of blood vessel stiffness. In the high blood pressure group, the healthy food pattern (fruits, meat, milk) was more strongly connected to blood vessel stiffness. This suggests that in children already developing high blood pressure, overall diet quality becomes even more important for protecting blood vessels

Previous research in adults has shown that junk food damages blood vessels, but this study is important because it shows this damage happens much earlier—starting in childhood. Most earlier studies looked at older children or adults. This research confirms that the harmful effects of poor diet begin very early and suggests that prevention should start in the preschool and early elementary years, not wait until children are teenagers

This study took measurements at only one point in time, so we can’t prove that junk food causes the blood vessel damage—only that they happen together. The study was done in South Africa, so results might be different in other countries with different food cultures. The researchers couldn’t measure everything that affects blood vessel health, so some important factors might have been missed. Also, the study relied on parents reporting what their children ate, which might not be completely accurate

The Bottom Line

Parents and caregivers should encourage children to eat more fruits, vegetables, lean meats, and dairy products while limiting junk foods like chips, sweets, fast food, and sugary treats. This recommendation is supported by strong evidence from this study and many others. Children should also be encouraged to be physically active and maintain a healthy weight. These changes are most effective when started early, ideally before age 10

All parents and caregivers of young children should pay attention to these findings, especially those with family history of high blood pressure or heart disease. Children who are overweight or already showing signs of high blood pressure should definitely focus on diet changes. Healthcare providers should use this information to counsel families about early prevention. Schools and community programs can also use this to improve food options for children

Blood vessel changes from poor diet can happen quickly—some damage may be visible within months of poor eating habits. However, improvements also happen relatively quickly when diet improves. Children who switch to healthier eating may see improvements in blood vessel function within weeks to a few months, though the most significant benefits come from maintaining healthy habits over years

Want to Apply This Research?

  • Track daily servings of junk foods versus healthy foods for each child. Set a goal like ’limit junk food to 2 servings per week’ and ’eat at least 3 servings of fruits or vegetables daily.’ Use the app to log meals and get weekly reports showing the ratio of healthy to unhealthy foods
  • Create a family challenge where everyone replaces one junk food snack per day with a healthy alternative (like replacing chips with apple slices or cookies with yogurt). Use the app to track participation and celebrate weekly wins. Set up reminders for healthy snack times
  • Monthly check-ins to review eating patterns and adjust goals. Track not just what kids eat, but also physical activity and any blood pressure checks from doctor visits. Create visual progress charts showing improvement in healthy food choices over time. Share results with family members to maintain motivation

This research shows associations between diet and blood vessel health in children but does not prove that junk food directly causes blood vessel damage. These findings should not replace professional medical advice. Parents concerned about their child’s blood pressure or diet should consult with their pediatrician or a registered dietitian. This study was conducted in South Africa and results may vary in different populations. Always speak with a healthcare provider before making significant dietary changes for your child, especially if your child has existing health conditions.