Sugar-sweetened beverages and ultra-processed foods are linked to higher inflammation markers in obese teenagers, according to a 2026 cross-sectional study of 70 Brazilian adolescents. Gram Research analysis shows that teens consuming sugary drinks had significantly elevated leptin/adiponectin ratios—a key inflammation indicator—and greater intake of processed foods. The findings suggest that reducing sugary drink and processed food consumption may help lower inflammation in overweight youth.
A new study of Brazilian teenagers found that those who drink sugary beverages and eat ultra-processed foods show higher levels of inflammation markers in their blood. Researchers measured special proteins called leptin and adiponectin that indicate inflammation. Teens who consumed sugar-sweetened drinks had worse body composition and higher inflammatory markers compared to those who didn’t drink them. The study suggests that cutting back on sugary drinks and processed foods could help reduce harmful inflammation in overweight adolescents.
Key Statistics
A 2026 cross-sectional study of 70 Brazilian adolescents found that those consuming sugar-sweetened beverages had significantly higher leptin/adiponectin ratios, indicating greater inflammation compared to non-consumers.
Among 70 obese teenagers studied in 2026, those who drank sugar-sweetened beverages (41 teens) consumed substantially more ultra-processed foods and showed larger waist and neck circumferences than the 29 non-drinkers.
A 2026 analysis of 70 Brazilian adolescents revealed that ultra-processed food intake was associated with increased body weight and pro-inflammatory biomarkers in obese youth.
The Quick Take
- What they studied: Whether drinking sugary beverages and eating ultra-processed foods increases inflammation in obese teenagers
- Who participated: 70 Brazilian teenagers aged 15-19 years old with obesity, split into those who drank sugary drinks (41 teens) and those who didn’t (29 teens)
- Key finding: Teens who drank sugar-sweetened beverages had significantly higher inflammation markers (measured by leptin/adiponectin ratio) and greater intake of ultra-processed foods compared to non-drinkers
- What it means for you: Limiting sugary drinks and processed foods may help reduce inflammation and improve health markers in overweight teens, though individual results vary and medical supervision is recommended
The Research Details
This was a cross-sectional study, which means researchers looked at a group of people at one point in time rather than following them over months or years. The team recruited 70 obese Brazilian teenagers and divided them into two groups: those who regularly drank sugary beverages (like soda and sweetened juices) and those who didn’t. They collected blood samples to measure two special proteins—leptin and adiponectin—that indicate inflammation levels in the body. They also measured body weight, muscle mass, and took detailed notes about what each teen ate using a 24-hour dietary recall, where participants describe everything they consumed in the previous day.
This research approach is important because it helps identify patterns between what teens eat and drink and their body’s inflammatory response. By measuring actual blood markers rather than just asking about health, the researchers got objective evidence of inflammation. The study used the NOVA food classification system, which categorizes foods from fresh and healthy to ultra-processed and unhealthy, making it easier to understand which specific foods matter most.
The study’s main strength is that it measured actual inflammation markers in blood rather than relying only on self-reported health. However, because it’s cross-sectional, it shows associations but cannot prove that sugary drinks cause inflammation—only that they appear together. The sample size of 70 teens is moderate, which limits how much we can generalize to all teenagers. The study was conducted in Brazil, so results may differ in other populations with different diets and genetics.
What the Results Show
Adolescents who consumed sugar-sweetened beverages showed significantly higher leptin/adiponectin ratios, which indicates greater inflammation in their bodies. These teens also had higher body weight, greater fat-free mass (muscle and organs), and higher resting metabolic rates. The sugar-drink consumers ate substantially more ultra-processed foods overall, consuming more total calories, protein, fat, cholesterol, carbohydrates, and saturated fats from these unhealthy sources. When researchers looked at ultra-processed food intake specifically, they found it was linked to increased body weight and larger waist and neck circumferences—measurements that predict inflammatory status. The combination of sugary drink consumption and high ultra-processed food intake created a pattern of unfavorable body composition and increased inflammation markers.
The study revealed that teens consuming sugary beverages also had higher intake of fiber, which was unexpected, suggesting their overall diet was high in both processed and some whole foods. The association between waist and neck circumference and inflammatory markers suggests that where the body stores fat matters for inflammation. The findings indicate that the inflammatory effect isn’t just about total calories but specifically about the types of foods consumed.
According to Gram Research analysis, this study aligns with existing research showing that sugary drinks and ultra-processed foods increase inflammation in young people. Previous studies in adults have shown similar patterns, and this research extends those findings to adolescents specifically. The use of leptin/adiponectin ratio as an inflammation marker is consistent with other recent research in this area.
The biggest limitation is that this study only shows associations, not cause-and-effect relationships—we can’t prove that sugary drinks cause inflammation, only that they appear together. The sample size of 70 teens is relatively small, making it harder to apply findings to all teenagers. The study was conducted at one point in time, so we don’t know if these patterns persist or change over time. The 24-hour dietary recall depends on teens accurately remembering what they ate, which can be unreliable. Results may not apply to teenagers in other countries with different diets and genetic backgrounds.
The Bottom Line
Moderate to strong evidence suggests that reducing sugar-sweetened beverage consumption and ultra-processed food intake may help decrease inflammation in obese adolescents. Teens should aim to replace sugary drinks with water, unsweetened tea, or milk, and choose fresh or minimally processed foods when possible. However, dietary changes should be made gradually and ideally with guidance from a healthcare provider or nutritionist.
This research is most relevant for obese or overweight adolescents, their parents, and healthcare providers working with teens. It’s also important for school nutrition programs and public health officials developing dietary guidelines. Teens with normal weight may still benefit from reducing sugary drinks, but the inflammatory effects may be less pronounced.
Changes in inflammation markers typically take 4-12 weeks to become measurable in blood tests, though some teens may feel improvements in energy and how they feel within 2-4 weeks. Significant changes in body composition usually take 8-12 weeks or longer with consistent dietary changes and physical activity.
Frequently Asked Questions
Do sugary drinks cause inflammation in teenagers?
A 2026 study of 70 obese teens found that those consuming sugar-sweetened beverages had higher inflammation markers compared to non-drinkers. However, the study shows association, not direct cause-and-effect, so other factors may contribute.
What foods increase inflammation in obese adolescents?
Ultra-processed foods—including sugary drinks, packaged snacks, and processed meats—were linked to higher inflammation markers in a 2026 study of 70 teenagers. Fresh and minimally processed foods showed better inflammatory profiles.
How quickly can reducing sugary drinks improve inflammation?
Blood inflammation markers typically show measurable changes within 4-12 weeks of dietary changes, though some teens report feeling better within 2-4 weeks. Individual results vary based on overall diet and lifestyle.
What is the leptin/adiponectin ratio and why does it matter?
This ratio measures two proteins in blood that indicate inflammation levels. Higher ratios suggest more inflammation, which is linked to obesity-related health problems. It’s a more precise marker than weight alone.
Should all teenagers reduce sugary drink intake?
Yes, health organizations recommend all teenagers limit sugary beverages regardless of weight. This 2026 study specifically showed inflammation risks in obese youth, but sugary drinks pose health risks for all adolescents.
Want to Apply This Research?
- Track daily sugar-sweetened beverage intake (count and ounces consumed) and ultra-processed food servings using the NOVA classification to monitor dietary patterns over time
- Set a specific goal to replace one sugary drink per day with water or unsweetened beverage, and identify one ultra-processed food to swap for a fresh alternative each week
- Weekly check-ins on beverage swaps and processed food reductions, with monthly progress photos and measurements of waist circumference to track physical changes alongside dietary improvements
This research shows associations between dietary patterns and inflammation markers in obese adolescents but does not prove direct cause-and-effect relationships. Results are based on a single cross-sectional study of 70 Brazilian teenagers and may not apply to all populations. Teenagers considering significant dietary changes should consult with a healthcare provider, registered dietitian, or nutritionist for personalized guidance. This information is for educational purposes and should not replace professional medical advice. Individual results vary based on genetics, overall lifestyle, physical activity, and other health factors.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.