A new wave of scientific reporting is raising the alarm about ultra-processed foods and their outsized role in the rising global rates of obesity and related chronic conditions. Recent evidence, brought together in a comprehensive review published in a leading health journal, Nature Reviews Endocrinology reveals that these foods are not just an indulgent convenience but a major driver of overeating, weight gain, and a raft of diseases that extend well beyond the waistline.

Ultra-processed foods — sometimes abbreviated as UPFs — have become staples in modern diets. They include items such as packaged snacks, pre-cooked meals, sweetened cereals, fizzy drinks, and flavoured granola bars. They’re easy to find in supermarkets, often affordable, and designed to taste irresistible. Yet, this convenience comes at a significant cost to public health.

Researchers involved in the latest review emphasise that the problem with UPFs isn’t simply the number of calories they contain, but their very nature. These foods are manufactured to be highly palatable, often by boosting levels of fat, sugar, and salt while stripping away water and fibre. The result is food that’s energy-dense but nutritionally poor. According to scientists, this composition encourages rapid, excessive energy intake, disrupts digestive processes, and can interfere with the body’s natural ability to signal fullness.

There is strong consensus among experts that ultra-processed foods can alter the way the digestive system absorbs nutrients. They can also change the composition of the gut microbiota — the collection of trillions of microorganisms living in our intestines. This microbiota plays a vital role in our overall health. When its function is disturbed by chemical additives, preservatives, or a lack of dietary fibre, the result can be chronic inflammation that increases the risk for a host of diseases.

The science behind UPFs is relatively new but growing rapidly. Experts in public health nutrition point out that just a century ago, food processing was largely a positive force — extending shelf life and adding nutrients to combat malnutrition. Chronic undernourishment was common across many parts of the world. The introduction of preservatives and early forms of food fortification helped to ensure a safer and more reliable food supply.

The landscape has changed dramatically. Today, ultra-processed foods dominate not just supermarket shelves but also diets worldwide. Their composition is now more about pleasure and profit than health. Scientific opinion has shifted: the risks from these foods now outweigh the benefits they once offered.

According to public health agencies such as the Centres for Disease Control and Prevention (CDC), over 40 percent of adults in the United States are classified as obese. In Malaysia, the number is not much different. The figure could be even higher according to new definitions that take into account more than just body mass index (BMI). Severe obesity affects nearly one in ten adults. The situation is mirrored in many other developed nations.

Obesity is not merely about excess weight. It brings with it increased risk for type 2 diabetes, heart disease, stroke, high blood pressure, fatty liver disease, certain cancers, and complications in pregnancy.

Visceral fat — often concentrated around the abdomen — is particularly concerning as it’s metabolically active and inflammatory. This type of fat sits deep within the body, surrounding vital organs and heightening the risk for metabolic disorders.

Recent research presented at a major endocrine society conference revealed a tripling in obesity-related cancers over two decades. This spike coincides with rising consumption of ultra-processed foods and suggests an urgent need for action at both individual and societal levels.

Why are ultra-processed foods so hard to resist? Scientists say it’s not only about taste. Additives ensure these products are soft, easy to chew, and pleasant to eat quickly. Their calorie density — a result of removing water and fibre while increasing fats and sugars — means people can eat large amounts before feeling full. Moreover, these foods are aggressively marketed, widely available, and require little or no preparation.

Beyond convenience and taste, there’s another danger: UPFs often crowd out healthier options. When individuals fill up on processed snacks or ready meals, they consume fewer fruits, vegetables, whole grains, and other nutrient-rich foods. Over time, this pattern leads to micronutrient deficiencies even as calorie intake climbs.

Alarmingly, some studies have estimated that ultra-processed foods may be responsible for over 120,000 preventable deaths each year in the United States alone. The damage is not limited to obesity or its immediate complications. Preservatives commonly found in UPFs can raise cardiovascular risk. High levels of added sugars contribute not only to diabetes but also to fatty liver disease and increased cancer risk.

There’s also mounting evidence about damage at the microscopic level. Chemical additives may erode the intestinal lining designed to keep bacteria contained within the gut. When this barrier breaks down, bacteria can leak into the bloodstream, triggering systemic inflammation — a key factor in many chronic diseases.

For those looking to reduce their intake of ultra-processed foods, experts recommend practical steps rather than drastic overnight changes. Reading ingredient labels helps identify foods with excessive additives or unfamiliar chemicals. Shopping along the outer edges of supermarkets — where fresh produce, meat, fish, eggs, and dairy are displayed — can make healthier choices easier.

Cooking at home using basic ingredients is another effective strategy for improving diet quality. While not everyone has time or equipment for elaborate meals, even simple dishes made from whole foods can provide better nutrition than most ready-made options. Experts suggest starting small: swapping a snack bar for a banana or choosing whole grain bread over white bread can make a meaningful difference.

Portion control remains challenging with ultra-processed foods because they’re engineered to be moreish. Experts advise reducing frequency rather than attempting complete avoidance at first. If fast food is a favourite indulgence, limiting it to once a month instead of weekly can have clear health benefits. For those whose diets are dominated by UPFs at every meal, working with a registered dietitian may help develop realistic alternatives and cooking skills.

Governments too have a role to play. Researchers urge policymakers to improve food environments through stricter labelling requirements and tighter controls on marketing unhealthy products — particularly those targeting children and young people.

Cutting back on ultra-processed foods is not simply about weight management but long-term health protection. Every organ in the body feels the impact of obesity and poor-quality diets. The science is clear: diets high in ultra-processed foods increase risks not only for diabetes and heart disease but also for cancer and inflammatory conditions that damage organs from within.

The challenge is formidable given how entrenched these foods have become in everyday life. They’re cheap, convenient, tasty — attributes that make them popular but ultimately harmful if consumed excessively. Yet change is possible when individuals are informed, motivated and supported by policies that make healthier choices more accessible.

The evidence linking ultra-processed foods with overeating and chronic disease is overwhelming. These products are engineered for pleasure rather than nourishment and pose risks that society can no longer afford to ignore. Small steps towards reducing consumption — supported by better labelling, public education and policy reform — can help turn the tide on obesity and its many complications.