Researchers studied what 400 college students in South Africa were eating and discovered two big problems: their diets were missing important nutrients like calcium and vitamin D, and their food choices were creating a lot of greenhouse gases that harm the environment. Nearly all students (99.8%) had poor diet quality that puts them at risk for serious health problems like heart disease and diabetes. Male students’ diets created more pollution than female students’ diets. The study shows that universities need to help students make healthier food choices that are also better for the planet.

The Quick Take

  • What they studied: Whether college students are eating healthy foods and how much their diets contribute to climate change through greenhouse gas emissions
  • Who participated: 400 students at a South African university, including both male and female students of typical college age
  • Key finding: Nearly all students (99.8%) had poor diet quality with missing nutrients, and their food choices created significant greenhouse gas emissions—with male students’ diets producing about 13% more pollution than female students’ diets
  • What it means for you: If you’re a college student, your current eating habits may not be giving your body the nutrients it needs and may be contributing more to climate change than necessary. Small changes toward eating more plant-based foods and fewer processed items could help both your health and the environment, though individual dietary changes work best alongside broader university food policy changes.

The Research Details

Researchers asked 400 college students to write down everything they ate over two separate days (including one weekend day) to get a realistic picture of their typical eating patterns. They used a method called a 24-hour food recall, where students report all their meals and snacks from the previous day. This was done twice to capture variation in eating habits. The researchers then checked whether students were getting enough of important nutrients like calcium, magnesium, vitamin D, and fiber by comparing their intake to official nutrition guidelines. They also used a scoring system called the Global Diet Quality Score to rate how healthy each student’s diet was overall. Finally, they used a special calculator called Plate Up for the Planet to estimate how much greenhouse gas pollution each student’s diet created based on the types of foods they ate.

This research approach is important because it captures real eating habits rather than asking people to guess what they usually eat. By measuring actual food intake over multiple days, the researchers got accurate information about nutrient gaps. Using the carbon footprint calculator shows the real environmental cost of food choices, connecting personal health decisions to climate impact—something that’s rarely studied in South Africa.

The study’s strength is its large sample size of 400 students and use of validated measurement tools (the Global Diet Quality Score and Plate Up for the Planet calculator). The repeated 24-hour recalls on different days (including weekends) provide more reliable dietary data than a single day. However, the study was conducted at one university in South Africa, so results may not represent all college students or other countries. The study is descriptive rather than experimental, meaning it shows what’s happening but can’t prove that poor diet quality directly causes disease in these students.

What the Results Show

The research revealed a widespread nutrition crisis among college students. Male students were eating too much carbohydrate (310.8 grams per day, above the recommended amount) and protein (88.06 grams per day, above recommendations), but were severely lacking in important minerals and vitamins. Specifically, 74.3% of male students weren’t getting enough calcium, 96.7% weren’t getting enough magnesium, and 92.8% weren’t getting enough vitamin D. Female students had different deficiencies: 94% weren’t getting enough calcium, 92.3% weren’t getting enough folate (a B vitamin), and many weren’t eating enough fiber. Most concerning, the Global Diet Quality Score showed that 99.8% of all students—meaning essentially every single student—had poor diet quality that puts them at high risk for developing serious diseases like heart disease, type 2 diabetes, and certain cancers. The environmental analysis showed that male students’ diets created an average of 5,671.55 kilograms of carbon dioxide equivalent per year, while female students’ diets created 5,020.36 kilograms—a meaningful difference driven largely by higher meat consumption among males.

The study found that the types of foods students were choosing—lots of processed foods and animal products—were the main drivers of both poor nutrition and high environmental impact. The research suggests that students’ food choices are heavily influenced by what’s available and affordable in the university food environment, indicating that individual students can’t fully solve this problem alone. The gender differences in environmental impact highlight how dietary patterns differ between male and female students, with males consuming more resource-intensive foods.

This study aligns with global research showing that college-age young adults typically have poor diet quality and high rates of nutrient deficiencies. The finding that nearly all students are at high risk for non-communicable diseases matches patterns seen in other countries. However, this appears to be one of the first studies in South Africa to connect student diet quality directly to environmental impact through greenhouse gas emissions, filling an important gap in understanding how young people’s food choices affect climate change.

The study was conducted at only one university in South Africa, so the results may not apply to students at other universities or in other countries with different food systems. The sample of 400 students, while reasonably large, came from a single institution. The study measured what students ate but didn’t track whether they actually developed diseases—it only assessed their risk based on diet quality. The research is a snapshot in time and doesn’t show whether these eating patterns are getting better or worse over time. Additionally, the study relied on students accurately remembering and reporting what they ate, which can be imperfect.

The Bottom Line

College students should work with their universities to increase access to affordable plant-based foods, whole grains, and fresh fruits and vegetables. Students should aim to include more calcium-rich foods (like leafy greens, fortified plant milks, or dairy if consumed), magnesium sources (nuts, seeds, whole grains), and vitamin D sources (fortified foods or supplements, especially in regions with limited sun). Universities should implement food policy changes to make healthy, sustainable options the default choice in dining facilities. Individual students can make incremental improvements by reducing processed food intake and choosing plant-based options more often, though systemic changes are needed for widespread impact. Confidence level: High for the finding that students have nutrient deficiencies and poor diet quality; Moderate for the specific environmental impact numbers, as these depend on calculator accuracy.

College students, especially those in South Africa and similar regions, should care about these findings because they directly affect their current health and future disease risk. University administrators and food service directors should prioritize these findings when planning menus and food policies. Parents of college students should be aware that campus food environments may not support healthy eating. Climate-conscious consumers should understand how their food choices affect greenhouse gas emissions. People with limited access to diverse foods should know that systemic food environment changes are needed, not just individual willpower. This research is less directly applicable to people with access to diverse, affordable healthy foods or those in countries with different food systems.

Students could see improvements in energy levels and digestion within 2-4 weeks of improving diet quality. Nutrient deficiency symptoms (like fatigue, weak bones, or poor immune function) may improve over 2-3 months with consistent dietary changes. Significant reductions in disease risk would take months to years of sustained healthy eating. Environmental impact reductions would be immediate in terms of carbon footprint but would only be meaningful if many students make changes simultaneously.

Want to Apply This Research?

  • Track daily intake of key nutrients students are deficient in: calcium (target 1,000-1,200 mg), magnesium (target 310-420 mg for adults), vitamin D (target 600-800 IU), and fiber (target 25-30 g). Log these nutrients weekly to identify patterns and gaps.
  • Set a goal to include one calcium-rich food, one magnesium-rich food, and one plant-based protein source in each day’s meals. Use the app to log these specific foods and track streaks of days meeting these targets. Start with one meal per day and gradually expand.
  • Use the app to track a ‘sustainability score’ by logging food choices and their estimated carbon footprint (simplified categories: high-impact animal products, medium-impact processed foods, low-impact plant-based foods). Review weekly to see patterns in environmental impact and set goals to shift toward lower-impact choices. Combine this with nutrient tracking to see how sustainable choices also improve nutrition.

This research describes patterns in college students’ diets and associated health risks but does not prove that individual students will develop diseases. The findings are based on one university in South Africa and may not apply to all populations or regions. If you have concerns about your nutrition or health, consult with a healthcare provider or registered dietitian who can assess your individual needs. This article is for educational purposes and should not replace professional medical or nutritional advice. The environmental impact estimates are based on calculator models and represent approximations rather than exact measurements of individual carbon footprints.