Researchers studied 190 young adults in Saudi Arabia to understand how ultra-processed foods (like packaged snacks, fast food, and sugary drinks) affect weight and body shape. They found that people who ate more of these ultra-processed foods had higher body weights, bigger waistlines, and were more likely to be overweight. The study suggests that eating fewer processed foods and more whole foods could help prevent weight problems. While this research was done in Saudi Arabia, the findings may apply to young adults in other countries too.

The Quick Take

  • What they studied: Does eating ultra-processed foods (packaged snacks, fast food, sugary drinks) make young adults more likely to gain weight and develop obesity?
  • Who participated: 190 young adults aged 18-25 years old from King Abdulaziz University in Jeddah, Saudi Arabia
  • Key finding: Young adults who ate the most ultra-processed foods had about 30% higher body weight measurements and were nearly 3 times more likely to be overweight compared to those who ate the least ultra-processed foods
  • What it means for you: Eating fewer packaged and fast foods and choosing more whole foods like fruits, vegetables, and home-cooked meals may help you maintain a healthier weight. However, this study shows a connection, not proof that ultra-processed foods directly cause weight gain.

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 researchers asked 190 young adults in Saudi Arabia about everything they ate over two 24-hour periods. They used a system called NOVA to sort foods into categories: unprocessed foods (like fresh fruits and vegetables), minimally processed foods (like frozen vegetables), processed foods (like canned goods with added salt), and ultra-processed foods (like chips, soda, and fast food). The researchers then measured each person’s weight, height, and waist size to calculate their body mass index (BMI) and check for signs of obesity.

This research approach is important because it shows real-world eating patterns and body measurements in a specific population. By looking at actual food choices and body measurements at the same time, researchers can spot patterns and connections. However, because this is a snapshot in time rather than following people over years, we can see that ultra-processed food and obesity are connected, but we can’t be completely sure that the food caused the weight gain.

This study has several strengths: it measured actual body weight and waist size rather than just asking people about their weight, and it adjusted for other factors like exercise and socioeconomic status that could affect results. However, the study only included young adults aged 18-25 in one city in Saudi Arabia, so results may not apply to older people or different populations. The study also relied on people remembering what they ate, which can be inaccurate.

What the Results Show

Young adults who ate the most ultra-processed foods had significantly higher measurements across the board. Their body mass index (a measure of weight relative to height) was about 30% higher than those who ate the least ultra-processed foods. Their waist circumference increased by about 23% on average. When researchers compared the group eating the most ultra-processed foods to the group eating the least, those eating the most were nearly 3 times more likely to be overweight (having a BMI over 25) and about 2.6 times more likely to have excess belly fat. These patterns held true for both men and women in the study.

The study found that ultra-processed food consumption was linked to higher measurements in multiple body areas, including weight, hip circumference, and waist size. The connection between ultra-processed foods and weight problems appeared consistent across different groups, suggesting this isn’t just affecting one type of person.

This research adds to growing evidence from studies around the world showing that ultra-processed foods are connected to weight gain and obesity. Previous research in other countries has shown similar patterns, so this Saudi Arabian study helps confirm that this problem isn’t limited to one region. The findings support what many health organizations have been saying: ultra-processed foods are a major risk factor for obesity.

This study has important limitations to consider. First, it only looked at young adults aged 18-25, so we don’t know if the same patterns apply to children or older adults. Second, the study was done in Saudi Arabia, so results may not apply exactly to other countries with different food cultures. Third, the study only measured food intake over two days, which may not represent someone’s typical eating habits. Fourth, because this is a snapshot study rather than following people over time, we can’t prove that ultra-processed foods directly cause weight gain—only that they’re connected. Finally, the study relied on people remembering what they ate, which can be inaccurate.

The Bottom Line

Based on this research, young adults should try to eat fewer ultra-processed foods like packaged snacks, fast food, and sugary drinks, and instead choose more whole foods like fresh fruits, vegetables, whole grains, and home-cooked meals. This recommendation has moderate confidence because the study shows a clear connection, though it doesn’t prove cause and effect. Consider reading food labels and choosing products with fewer ingredients and less added sugar and salt.

Young adults aged 18-25 should pay special attention to this research, as this is the age group studied. Anyone concerned about weight management or obesity risk should consider these findings. Parents of young adults and policymakers interested in public health should also care about this research. However, people with specific medical conditions should talk to their doctor before making major dietary changes.

You likely won’t see major weight changes overnight. Research suggests that consistent dietary changes typically show noticeable results in body weight and measurements within 4-8 weeks, though individual results vary. Building lasting habits takes time, so focus on making gradual, sustainable changes rather than expecting immediate results.

Want to Apply This Research?

  • Track your ultra-processed food servings daily (count items like packaged snacks, fast food meals, sugary drinks, and processed desserts) and compare it to your whole food servings (fresh fruits, vegetables, whole grains, home-cooked meals). Aim to gradually reduce ultra-processed foods from your current intake.
  • Use the app to set a weekly goal to replace one ultra-processed food item with a whole food alternative. For example, swap one fast food meal for a home-cooked dinner, or replace sugary drinks with water. Track these swaps to build momentum and see your progress.
  • Weekly check-ins: Review your ultra-processed food intake each week and track your progress toward reducing it. Monthly measurements: If possible, track your weight and waist circumference monthly to see if dietary changes correlate with body measurements. Use the app to identify your most common ultra-processed foods and create specific replacement strategies for each.

This research shows a connection between ultra-processed foods and weight gain in young adults, but it does not prove that ultra-processed foods directly cause obesity. Individual results vary based on many factors including genetics, physical activity, overall calorie intake, and other lifestyle factors. Before making significant dietary changes, especially if you have existing health conditions, please consult with a healthcare provider or registered dietitian. This information is for educational purposes and should not replace professional medical advice.