Swedish researchers studied nearly 3,100 teenagers to see how eating sugary foods affects their overall nutrition. They found that teens who eat more sugar-sweetened foods tend to eat fewer healthy foods like vegetables, fruits, fish, and dairy products. This means they’re missing out on important vitamins and minerals their growing bodies need. The study shows that even moderate amounts of added sugar can make it harder for teenagers to get enough nutrients like vitamin D, fiber, and healthy fats—even if they’re eating enough total calories.
The Quick Take
- What they studied: How much sugar Swedish teenagers eat and whether it affects what other nutrients and foods they consume
- Who participated: 3,099 Swedish teenagers around ages 12, 15, and 18 years old from across the country, representing a typical mix of the teenage population
- Key finding: Teenagers who eat more sugar-sweetened foods eat significantly less of healthy foods like vegetables, fruits, fish, and dairy. They also get fewer important vitamins and minerals, even when they’re eating enough total calories. This happens because sugary foods are replacing nutritious foods in their diet.
- What it means for you: If you’re a teenager or parent, this suggests that cutting back on sugary foods and drinks might help ensure you’re getting all the nutrients your body needs to grow and stay healthy. This is especially important for nutrients like vitamin D, fiber, and healthy fats that many teens don’t get enough of anyway.
The Research Details
This study used information from a large Swedish national survey called Riksmaten Adolescents from 2016-17. Researchers asked teenagers to describe everything they ate over two separate 24-hour periods. This gave them a detailed picture of what Swedish teens were actually eating. The researchers then organized the teenagers into five groups based on how much sugar they consumed—from the lowest sugar eaters to the highest. They compared what nutrients and foods each group was eating, while accounting for differences like whether the teenager was male or female and what grade they were in. They also adjusted for cases where teenagers might have accidentally reported eating more or less than they actually did.
This approach is useful because it shows real-world eating patterns in a large group of teenagers, rather than just looking at one person or a small group. By comparing teenagers with different sugar intake levels, researchers could see whether eating more sugar was connected to eating fewer healthy foods. This type of study is good for spotting patterns, though it can’t prove that sugar directly causes people to eat less healthy food.
This study has several strengths: it included a large, nationally representative group of Swedish teenagers, so the results likely reflect what’s happening across the whole country. The researchers collected detailed food information using two separate 24-hour recalls, which is considered a reliable method. They also adjusted their analysis for several factors that could affect the results. However, because this is a snapshot study (not following the same teens over time), we can’t be completely certain that eating sugar causes people to eat fewer healthy foods—only that these patterns are connected. Also, the study only included Swedish teenagers, so results might be different in other countries with different food cultures.
What the Results Show
The main finding was clear: as teenagers ate more sugar, they ate less of almost every healthy food group. Teenagers with the highest sugar intake ate significantly less vegetables, fruit, dairy products, meat, and fish compared to those eating the least sugar. This pattern held true even after accounting for how many total calories they were eating, which means it’s not just about eating more food overall.
When researchers looked at specific nutrients, they found that higher sugar intake was connected to lower intakes of almost all vitamins and minerals—including calcium, iron, zinc, and B vitamins. Teenagers also got less dietary fiber and healthy fats when they ate more sugar. Interestingly, the only nutrient that went up with more sugar intake was vitamin C, mainly because fruit juice (which contains sugar) is a source of vitamin C.
The researchers found that teenagers eating more than about 13% of their daily calories from free sugars (added sugars plus sugars naturally in juice) were significantly less likely to meet recommended nutrient levels. But here’s an important finding: even at lower sugar intake levels, many teenagers weren’t getting enough vitamin D, selenium, fiber, and polyunsaturated fats (healthy fats). This suggests that Swedish teenagers overall might not be eating enough of these nutrients, and eating more sugar makes the problem worse.
The study found that total energy intake (overall calories) wasn’t higher in teenagers who ate more sugar. This is important because it shows that sugary foods aren’t just adding extra calories—they’re actually replacing nutritious foods in the diet. The researchers also noted that fruit juice had a significant effect on vitamin C intake patterns, showing that the source of sugar matters when looking at overall nutrition.
This research supports what other studies have found: eating more sugar is connected to eating fewer healthy foods and getting fewer nutrients. However, this is one of the first studies to look specifically at this pattern in Swedish teenagers, and it provides detailed information about which nutrients are most affected. The findings align with international nutrition guidelines that recommend limiting added sugars, though this study provides new evidence about why this recommendation matters for teenagers specifically.
This study has several important limitations to keep in mind. First, it only shows associations (connections) between sugar intake and nutrient intake—it doesn’t prove that eating sugar causes people to eat fewer healthy foods. Second, the study relied on teenagers remembering and reporting what they ate, which can be inaccurate. Third, the study only included Swedish teenagers, so the results might not apply to teenagers in other countries with different food environments and cultures. Finally, this is a snapshot in time (2016-17), so eating patterns may have changed since then.
The Bottom Line
Based on this research, teenagers should aim to limit sugary foods and drinks and instead focus on eating more vegetables, fruits, whole grains, dairy products, fish, and lean meats. This is especially important for getting enough vitamin D, fiber, and healthy fats. Parents can help by offering water instead of sugary drinks, limiting sugary snacks, and making sure meals include nutrient-dense foods. These recommendations have moderate to strong evidence supporting them, though this particular study shows associations rather than proving cause-and-effect.
This research is most relevant to teenagers, parents of teenagers, and anyone involved in feeding teenagers (like school cafeteria workers or coaches). It’s particularly important for teenagers who drink a lot of sugary beverages or eat many sugary snacks. The findings may be less directly applicable to people in countries with very different food cultures than Sweden, though the general principle likely applies widely. This research doesn’t apply to people with specific medical conditions that require different dietary approaches—those individuals should consult with their healthcare provider.
If a teenager reduces their sugar intake and increases healthy foods, they might notice some changes within a few weeks (like having more energy or feeling fuller longer). However, the real benefits—like having better nutrient levels and improved long-term health—develop over months and years of consistent eating habits. This isn’t a quick fix, but rather a lifestyle change that pays off over time.
Want to Apply This Research?
- Track daily added sugar intake (in grams) and count servings of nutrient-dense foods (vegetables, fruits, whole grains, dairy, fish, lean meat). Set a goal to stay under 25-30 grams of added sugar daily while eating at least 5 servings of fruits and vegetables.
- Use the app to set reminders to drink water instead of sugary drinks, log meals to see patterns in sugar intake, and get suggestions for swapping sugary snacks for nutrient-dense alternatives. Create a weekly challenge to try one new vegetable or fish recipe.
- Weekly review of sugar intake trends and nutrient-dense food consumption. Monthly check-ins to see if energy levels, digestion, or overall feeling of wellness have improved. Track whether nutrient intake goals are being met by logging complete meals and reviewing nutritional summaries.
This research shows associations between sugar intake and nutrient intake in Swedish teenagers but does not prove that sugar directly causes nutrient deficiencies. Individual nutritional needs vary based on age, activity level, health status, and other factors. Teenagers with specific health conditions, eating disorders, or dietary restrictions should consult with a healthcare provider or registered dietitian before making significant dietary changes. This information is for educational purposes and should not replace professional medical or nutritional advice.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.