Researchers studied 129 teenagers with obesity to see if combining exercise with personalized nutrition advice worked better than exercise alone. Over 12 weeks, teens who did aerobic exercise AND received dietary guidance lost significantly more weight, reduced belly fat, and improved their fitness compared to those who only exercised. The combination approach helped teens lose more body fat while keeping muscle, and they showed better heart and lung function. This suggests that when teenagers tackle weight loss with both exercise and smart eating habits together, they get much better results than trying just one approach.

The Quick Take

  • What they studied: Whether combining exercise with personalized nutrition advice helps obese teenagers lose weight and get healthier better than exercise alone
  • Who participated: 129 teenagers with obesity (ages not specified in abstract) who received treatment between 2021-2024. One group of 61 teens did aerobic exercise only, while 68 teens did aerobic exercise plus received personalized nutrition guidance
  • Key finding: After 12 weeks, teenagers who combined exercise with nutrition guidance lost significantly more weight, reduced waist size by more, lost more body fat, and improved their fitness levels compared to those who only exercised (all differences were statistically significant with P < .01, meaning very unlikely to be due to chance)
  • What it means for you: If you’re a teenager struggling with weight, combining regular aerobic exercise with personalized healthy eating guidance appears to work much better than exercise alone. However, this was a retrospective study, so more research is needed to confirm these findings apply broadly to all teenagers

The Research Details

This study looked back at records of 129 teenagers with obesity who received treatment between January 2021 and December 2024. The researchers divided them into two groups: one group did aerobic exercise (like running, cycling, or dancing) for 12 weeks, while the other group did the same exercise but also received personalized nutrition advice tailored to their individual caloric needs and proper balance of proteins, carbohydrates, and fats. Before and after the 12-week program, researchers measured things like weight, waist size, body fat percentage, heart and lung function, and physical fitness abilities.

Because this was a retrospective study (looking back at past records rather than following new participants forward), the researchers couldn’t randomly assign teenagers to groups, which is the gold standard for research. Instead, they analyzed data from teenagers who had already chosen their treatment path. This means some differences between groups might be due to who chose which program rather than the program itself.

Understanding whether combining exercise with nutrition guidance works better than exercise alone is important because obesity in teenagers is becoming more common worldwide and can lead to serious health problems like diabetes and heart disease at a young age. If researchers can identify the most effective approach, teenagers and their families can make better choices about how to tackle weight and health issues. This study helps show that a combined approach might be more powerful than doing just one thing.

Strengths: The study included a decent number of participants (129 total), measured multiple important health markers (weight, body fat, fitness, heart/lung function), and both groups received structured exercise programs so the comparison was fair. Weaknesses: This was a retrospective study using past records rather than a randomized controlled trial (the gold standard), so we can’t be completely certain the nutrition program caused the better results—other differences between the groups might explain the findings. The study doesn’t specify the teenagers’ ages or other details that might affect results. We also don’t know how well teenagers stuck to the nutrition advice or if they had other lifestyle differences.

What the Results Show

After 12 weeks, the group that combined exercise with nutrition guidance had significantly better results across multiple measures. They lost more weight (measured by body mass index), had greater reductions in waist circumference (belly size), lost more body fat percentage, and had greater reductions in visceral fat (the dangerous fat around organs). All of these differences were statistically significant, meaning they were very unlikely to happen by chance.

Beyond just weight loss, the combined group also improved more in physical fitness and health markers. They gained more lean body mass (muscle), performed better on a step test (a measure of aerobic fitness), had better vital capacity (how much air their lungs can hold), and showed greater improvements in muscular endurance, flexibility, and agility. These improvements suggest that the combination approach didn’t just help them lose fat—it actually helped them become more fit and stronger.

The results suggest that exercise and nutrition guidance work together synergistically, meaning they work better together than either one alone would. This is important because it shows that teenagers can’t just exercise their way to health without paying attention to what they eat, and vice versa.

The study found that teenagers in the combined group maintained or even increased their lean body mass (muscle) while losing fat, which is ideal because it means they weren’t just losing weight—they were losing the right kind of weight. The improvements in heart and lung function (vital capacity) and aerobic fitness (step test performance) suggest that the combined approach also improved cardiovascular health, which is crucial for preventing heart disease later in life. The gains in flexibility and agility indicate that teenagers became more physically capable and mobile overall.

Previous research has shown that exercise alone can help with weight loss in teenagers, and that nutrition intervention alone can also help. This study adds to that knowledge by showing that combining both approaches produces better results than either alone. The finding that the combination is synergistic (better together than separately) aligns with what many health experts recommend, but this study provides specific evidence for teenagers with obesity. The magnitude of improvements in body composition and fitness suggests that the combined approach may be more effective than what previous single-intervention studies have shown.

The biggest limitation is that this was a retrospective study (looking back at past data) rather than a randomized controlled trial where researchers randomly assign people to groups. This means teenagers may have chosen their group based on their own preferences or circumstances, which could affect results. We don’t know if the groups were similar in other important ways like age, starting fitness level, family support, or how motivated they were. The study doesn’t tell us how long the benefits lasted after the 12 weeks ended, or whether teenagers were able to maintain their improvements. We also don’t know specific details about the nutrition guidance—how personalized was it, how often did teenagers meet with nutritionists, and how well did they follow the advice? Without this information, it’s hard to know exactly what made the difference.

The Bottom Line

For teenagers with obesity: Combining regular aerobic exercise (at least several times per week) with personalized nutrition guidance appears to be significantly more effective than exercise alone for weight loss, fat reduction, and fitness improvement (moderate to high confidence based on this study, though more research is needed). The nutrition guidance should be tailored to individual caloric needs and include proper balance of proteins, carbohydrates, and fats. For parents and healthcare providers: Consider recommending a combined approach rather than focusing on exercise or diet alone. For best results, work with healthcare professionals who can provide both structured exercise programs and personalized nutrition guidance.

This research is most relevant for teenagers with obesity who are looking to lose weight and improve their health. It’s also important for parents of teenagers with weight concerns, school health programs, and healthcare providers who work with adolescents. The findings may be less applicable to teenagers at healthy weights or those with other medical conditions that affect metabolism. Adults may find some relevance, but this study specifically looked at adolescents, so results might differ for other age groups.

Based on this study, significant improvements in weight, body fat, and fitness can be seen within 12 weeks of combining exercise with nutrition guidance. However, this is a relatively short timeframe. Teenagers should expect to see noticeable changes in how they feel and look within 4-6 weeks, with more substantial improvements by 12 weeks. Long-term success likely requires maintaining both the exercise and healthy eating habits beyond the initial 12 weeks, though this study didn’t track teenagers after the program ended.

Want to Apply This Research?

  • Track weekly waist circumference measurements and body weight, along with aerobic exercise minutes completed and nutrition adherence (percentage of meals following personalized guidelines). Also track a simple fitness metric like how many steps completed in a step test or how long they can exercise before getting tired.
  • Set up daily reminders for meal planning based on personalized caloric and macronutrient targets, log aerobic exercise sessions (type, duration, intensity), and weekly check-ins to review progress on weight and fitness metrics. Create a combined ’exercise + nutrition’ streak tracker to motivate consistent adherence to both components.
  • Establish baseline measurements (weight, waist circumference, fitness level) and track weekly or bi-weekly. Create visual progress charts showing both exercise compliance and nutrition adherence alongside body composition changes. Set 4-week and 12-week milestone goals. Include reminders to reassess fitness levels monthly (step test, flexibility, endurance) to show improvements beyond just weight loss.

This research suggests that combining exercise with nutrition guidance may be effective for weight loss and fitness in teenagers with obesity, but it was a retrospective study, which means we cannot be completely certain about cause and effect. These findings should not replace personalized medical advice from a healthcare provider. Before starting any new exercise program or making significant dietary changes, teenagers and their families should consult with their doctor or a registered dietitian, especially if the teenager has any underlying health conditions. Results may vary based on individual factors, adherence to the program, and other lifestyle factors not measured in this study. This information is for educational purposes and should not be considered medical advice.