If you’re a young adult on the go, it’s easy to grab fast food or a packaged snack without a second thought. But ultra-processed foods – those chips, sodas, sugary cereals, and drive-thru meals – could be quietly steering your health in the wrong direction. These convenient foods dominate modern diets (over half of all calories in the U.S.), often packed with added sugar, salt, and unhealthy fats, keck.usc.edu. While we’ve long known that diets heavy in ultra-processed items raise the risk of type 2 diabetes and other chronic issues in older adults, new evidence shows the danger starts much earlier. Prediabetes, a silent precursor to diabetes, is increasingly affecting young people – and ultra-processed foods are a big reason why. The good news? By understanding the risks and making smarter choices, you have the power to protect your future health.
Ultra-Processed Foods Are Everywhere (And What That Means for You)
Take a look at a typical day of eating for many teens or 20-somethings: maybe a sugary cereal or flavored yogurt for breakfast, a vending machine soda and chips after class, and fast-food or pizza for dinner. These are all ultra-processed foods (UPFs) – products altered by multiple industrial processes, loaded with additives, and far removed from their natural form. Common examples include soft drinks, candy, packaged snacks, instant noodles, sweetened breakfast cereals, chicken nuggets, and many restaurant or drive-thru items. What’s the issue with these foods? They’re usually high in refined sugar, sodium, and unhealthy fats but low in fiber and nutrients, pharmacytimes.com. In other words, they flood your body with quick calories and sugar without providing the nourishment it needs.
For adults, diets rich in ultra-processed foods have been clearly linked to health problems like obesity, heart disease, and type 2 diabetes. But until recently, research on how these foods affect younger people was limited to keck.usc.edu. That’s worrisome, because many young adults assume they can get away with a junk-food-heavy diet with no immediate consequences. In reality, the effects might just be harder to see in the short term. You might feel fine today, but inside the body, these foods can be quietly undermining your blood sugar control and setting the stage for future illness. Prediabetes – elevated blood sugar not yet in the diabetic range – often has no obvious symptoms. So a 19-year-old could be on the road to diabetes and not know it. This is why experts are paying closer attention to what younger generations are eating.
Prediabetes: The Silent Early Warning in Youth
Prediabetes is essentially a yellow alert for your health. It means your blood sugar levels are higher than normal, but not high enough to be diagnosed as diabetes. Think of it as the body’s early warning system that metabolic trouble is brewing. The scary part is how common prediabetes has become among young people. Nearly one in three U.S. adolescents (ages 12–19) now has prediabetes – a rate that more than doubled from about 12% in the early 2000s to almost 28% by 2018 diabetes.org. In 2023, the CDC estimated that roughly 32% of teens have prediabetes, highlighting a fast-growing crisis. Many of these youth feel perfectly healthy and have no idea their blood sugar is elevated.
Why does this matter? Because developing type 2 diabetes at a young age can lead to more serious health problems over a lifetime. If you’re diagnosed with diabetes in your teens or twenties, that means more years for the disease to potentially damage your heart, kidneys, nerves, eyes, and other organs. Research shows that early-onset type 2 diabetes often results in worse long-term complications compared to getting the disease later in life. To put it simply, the earlier diabetes strikes, the more time it has to wreak havoc. That’s why preventing or delaying diabetes is so critical. And since obesity and poor diet are major risk factors for prediabetes and diabetes, addressing those factors in young adulthood can go a long way pharmacytimes.com. Prediabetes truly is a silent warning – but it’s also a window of opportunity. With the right changes in food and lifestyle, you can stop prediabetes in its tracks and avoid progressing to full-blown diabetes diabetes.org.
New Research Exposes the Risk of Ultra-Processed Diets
A landmark new study by researchers at the University of Southern California (USC) has shed light on just how dangerous ultra-processed foods can be for young adults. The study followed 85 young men and women (ages 17–22) over four years, tracking their diets and health markers. What they found should be a wake-up call for anyone in their teens or twenties: even a small increase in ultra-processed food intake was linked to a significant jump in prediabetes risk. Specifically, for each 10% increase in the proportion of calories coming from ultra-processed foods, the risk of developing prediabetes shot up by 64%. That’s a huge leap for what might seem like a minor change – for example, adding an extra bag of chips or a sugary drink to your daily routine. The participants who ate more ultra-processed items also showed a 56% higher risk of impaired glucose regulation, meaning their bodies were losing the ability to manage blood sugar effectively. They even had elevated insulin levels on their tests – an early sign of insulin resistance, where your body has to pump out more and more insulin to handle the sugar in your blood.
“Our findings show that even modest increases in ultra-processed food intake can disrupt glucose regulation in young adults at risk for obesity. These results point to diet as a modifiable driver of early metabolic disease, and an urgent target for prevention strategies among young people,” said Dr. Vaia Lida Chatzi, the study’s senior author, keck.usc.edu.
In other words, what you eat in your youth does matter – it can either set you up for stable health or quietly nudge you toward metabolic problems. This USC study, one of the first to examine ultra-processed diet effects in young people, was published in a scientific journal in late 2025 at keck.usc.edu. Its message is clear: ultra-processed foods are not just harmless indulgences. They can actively harm your body’s sugar-handling machinery even in the short span of a few years. The study’s first author, Yiping Li, emphasizes that cutting back on these foods can help prevent prediabetes and type 2 diabetes in young adults. It’s an empowering finding – because while you can’t change your genes or your childhood, you can change your diet.
Pro Tip: Start small. Try swapping one daily ultra-processed snack for a healthier option you enjoy. For example, trade that afternoon’s candy bar for a handful of nuts and an apple. Little changes like this can reduce your sugar intake and still satisfy your cravings – and over time, they add up to big benefits.
Why Ultra-Processed Foods Spike Blood Sugar and Risk
What makes ultra-processed foods so good at undermining your metabolic health? First, these foods are often packed with easily digestible starches and added sugars. That means when you drink a bottle of soda or eat a doughnut, you’re flooding your system with sugar that gets absorbed rapidly. Your blood sugar spikes, and your pancreas has to release a surge of insulin to try to move all that glucose into cells. Do this repeatedly – soda at lunch, candy in the afternoon, ice cream at night – and you’re overworking your body’s sugar-control system. Over time, the cells start responding less to insulin (a condition known as insulin resistance), and blood sugar stays elevated more often. This is a direct path toward prediabetes and eventually type 2 diabetes.
Ultra-processed foods are also typically low in fiber and protein, which are nutrients that slow down sugar absorption and keep you feeling full. Without fiber, that refined carbohydrate rush from a bowl of sugary cereal hits fast and then crashes, often leaving you hungry again soon. That can lead to overeating and weight gain. In fact, research has found that people tend to consume more calories and gain weight when fed an ultra-processed diet compared to a diet of unprocessed foods, even when presented with meals of equal calories. Excess body fat, especially around the waist, makes it harder for insulin to work properly, raising diabetes risk further. It becomes a vicious cycle: the more ultra-processed foods you eat, the more you crave them, and the more your metabolism struggles.
Moreover, diets high in ultra-processed items often displace healthier foods. If a young adult fills up on fries and soda, that’s likely replacing a balanced meal with vegetables, lean protein, and whole grains that would have provided steady energy and important nutrients. Over time, a poor diet like this can lead to deficiencies in nutrients like magnesium or vitamins that are important for glucose metabolism. Some scientists also suspect that additives and preservatives common in ultra-processed products may contribute to chronic inflammation or other changes in the body that worsen insulin resistance. While research on those mechanisms is ongoing, one thing is clear: eating mostly ultra-processed fare puts young people at a serious disadvantage when it comes to blood sugar health, pharmacytimes.com. It’s like constantly revving a car engine with low-quality fuel – eventually, something’s going to break down.
The bottom line is that ultra-processed foods create a perfect storm for metabolic trouble: high sugars and fats, low nutrients, and lots of calories packed into tempting, easy-to-eat packages. They’re engineered to taste great and are heavily marketed, so it takes awareness and effort to cut back. But as we’ve seen, your future health may depend on it.
Taking Control: Healthy Habits to Prevent Prediabetes
Reading about these risks might feel overwhelming, but it’s actually motivating news. Prediabetes and even type 2 diabetes can be delayed or prevented – and you have the tools to do it. It all starts with conscious choices in your daily routine. Here are some powerful yet practical steps you can take right now to protect your health:
- Limit sugary drinks and snacks: Beverages like soda, sweetened coffees, energy drinks, and many bottled juices are loaded with sugar. The same goes for candy, cookies, and chips. These items are full of empty calories that spike blood sugar quickly, diabetes.org. Try to cut back gradually – for instance, if you usually have two sodas a day, switch one of them out for water or a zero-sugar alternative. Replace candy or pastries with naturally sweet whole fruits. Your taste buds will adjust over time, and your body will thank you.
- Focus on whole, nutrient-rich foods: Center your meals around whole foods that help stabilize blood sugar. Aim to eat plenty of vegetables, especially non-starchy ones like broccoli, leafy greens, carrots, and peppers. Include high-fiber fruits (berries, apples, oranges), whole grains (oats, brown rice, quinoa), lean proteins (chicken, fish, beans), and healthy fats (avocado, nuts, olive oil). These foods provide the nutrition your body needs and are digested more slowly, preventing big sugar spikes. diabetes.org. You don’t have to be perfect – just try to make more of your snacks and meals come from real, unprocessed ingredients.
- Cook and plan meals at home: It can be fun and rewarding to cook your own food. When you prepare meals at home, you control the ingredients. You can reduce added sugars and unhealthy fats by using fresh ingredients and herbs for flavor. Try meal-prepping for the week or cooking with friends. If you do eat out, opt for dishes that are closer to whole foods (like a burrito bowl with beans, rice, and veggies) rather than ultra-processed picks (like fried items or processed meats).
- Watch portions and eat mindfully: It’s not just what you eat but how you eat. Slow down and listen to your body’s hunger signals. Ultra-processed foods are easy to overeat because they’re designed to be hyper-palatable (think: you can inhale a large order of fries in minutes). Practice serving reasonable portions, and try not to eat mindlessly in front of screens. By savoring your food and stopping when you’re comfortably satisfied, you’ll prevent overeating. This helps with weight management – a key factor, since maintaining a healthy weight greatly lowers your risk of insulin resistance and diabetes pharmacytimes.com.
- Stay active and build an exercise habit: Moving your body is one of the most effective ways to improve insulin sensitivity. When you exercise – whether it’s walking, cycling, dancing, or hitting the gym – your muscles use up blood sugar for fuel. Aim for at least 30 minutes of moderate activity most days. Even activities like brisk walking or taking the stairs can make a difference. Regular exercise, combined with a balanced diet, will help you manage your weight and keep your blood sugar levels in check.
- Get adequate sleep and manage stress: It might surprise you, but sleep and stress play a role in blood sugar control, too. Not getting enough sleep or being chronically stressed can mess with your metabolism and hormone balance, sometimes increasing cravings for sugary, processed foods. Try to get a consistent 7–8 hours of sleep per night, and find healthy outlets for stress (exercise, meditation, talking to a friend) instead of reaching for a bag of chips. A well-rested, calm body regulates sugar better.
Finally, don’t hesitate to get support and guidance. Ask your healthcare provider to check your blood sugar (a simple test can tell if you have prediabetes). diabetes.org. If you do find your blood sugar is elevated, work with your doctor or a nutritionist on a plan to reverse it. Early action is key – by making changes now, you can often bring your blood sugar back to a normal range and prevent diabetes altogether. diabetes.org. Many people have successfully turned their health around by adopting these habits, and you can too. Remember: Every healthy choice you make – swapping fries for a salad, saying no to that second cookie, taking a walk after dinner – is an investment in your future. Young adulthood is the perfect time to build habits that will keep you healthy for decades. Instead of letting ultra-processed foods quietly push you toward prediabetes, you can push back. By staying informed and being proactive about what you put on your plate, you’re not just avoiding a diagnosis – you’re gaining energy, confidence, and long-term well-being. It’s never too early to start, and the changes you make today can truly set the foundation for a healthier tomorrow.
