Introduction
Food processing involves any method that changes food from its natural form, such as drying, freezing, milling, canning, or adding ingredients like salt, sugar, fat, or other additives for flavor or preservation. Nearly all foods and beverages undergo some form of processing before they are bought or consumed. The term "processed foods" includes a wide range of items, from frozen vegetables and canned beans to candies, chips, and sodas. To classify these foods based on the degree and purpose of processing, researchers developed the NOVA classification system. It has classified food into four groups: unprocessed/minimally processed, processed culinary ingredients, processed foods, and ultra-processed foods (UPFs).
UPFs are industrially produced edible items derived from natural or synthetic sources, designed for high profitability and convenience, often enhanced with additives like preservatives, colorings, and flavorings. They are commonly processed through methods such as molding, extruding, hydrogenation, or frying. These products include sugary beverages, snacks, ready-to-eat meals, and reconstituted meat products. The rapid dietary transition in lower and middle-income countries (LMICs) is marked by an increasing demand for UPFs.
The Rise of Ultra-Processed Foods in Nepal
The proliferation of UPFs is driven by socioeconomic factors including urbanization, economic growth, and lifestyle changes. Marketing strategies target all age groups, with children and adolescents being particularly vulnerable. Cultural shifts towards convenience and fast-paced lifestyles have made UPFs a dietary mainstay. Economic disparities also play a role, as lower-income populations often rely on cheaper energy-dense UPFs due to financial constraints.
Over the past 60 years, advancements in food science and grocery retailing have led to a significant increase in the production and consumption of ultra-processed foods. Initially prevalent in high-income countries, this trend has now spread globally across all income levels. The increasing consumption of UPFs is a significant public health issue with profound implications for nutrition and health outcomes. Their consumption has surged globally, correlating with rising rates of obesity, diabetes, cardiovascular diseases, and other non-communicable diseases (NCDs).
Nutrient Composition of Ultra-Processed Foods
Ultra-processed foods are characterized by their high energy content and excessive levels of added sugars, sodium, unhealthy fats like trans fats and saturated fats, and refined carbohydrates. They also tend to lack essential nutrients found in less-processed and whole foods, such as dietary fiber, vitamins (particularly vitamin C and B vitamins), and minerals like potassium and magnesium. UPFs undergo extensive processing that often removes natural nutrients and fiber, replacing them with synthetic additives to improve flavor, texture, and shelf-life. This nutrient profile contributes to their calorie-dense nature and raises concerns about their potential negative impact on health when consumed regularly as a significant part of the diet. They promote overeating due to their convenience, hyper-palatable formulations, disruption of satiety signals, and pervasive marketing, often aimed at children.
Additionally, UPFs frequently contain harmful chemicals such as contaminants from high-temperature cooking, industrial additives that cause inflammation and gut microbiota imbalances, and hormone-disrupting compounds from plastics used in food manufacturing and packaging.
Health Implications of UPF Consumption
Ultra-processed foods present significant health risks that extend well beyond their nutritional content and calorie density. Unlike natural whole foods, where components are digested slowly within their original matrix, UPFs are typically dense in calories and rich in free sugars, refined starches, unhealthy fats, and sodium. These factors contribute to their association with rising global rates of obesity and non-communicable diseases. Beyond their poor nutritional quality, UPFs are hyper-palatable and may contain potentially addictive additives that our digestive systems struggle to break down, altering the gut microbiome and potentially promoting disease in susceptible individuals.
Intensive processing methods can further disrupt the food's structure, affecting digestion and nutrient absorption, while additives like non-sugar sweeteners and emulsifiers have been linked to adverse health effects such as gut inflammation and cancer. Industrial processes used in UPFs also produce harmful substances like acrylamide and advanced glycation end products, which are implicated in chronic inflammatory conditions. Similarly, contaminants from packaging materials used in UPFs pose additional health risks, such as leukemia and other systemic cancers. These diverse factors collectively underscore the complex mechanisms through which UPFs contribute to adverse health outcomes, highlighting the importance of minimizing their consumption in favor of whole, minimally processed foods for overall health and well-being.
Obesity and Metabolic Syndrome
Research consistently links high UPF consumption to an increased risk of obesity and metabolic syndrome. A study conducted in Brazil found a 7% increase in the risk of developing Metabolic Syndrome (MetS) for every additional 150 grams of ultra-processed food consumed per day. Furthermore, individuals in the highest quartile of UPF consumption had a 33% higher risk compared to those in the lowest quartile. Studies show that individuals consuming high amounts of UPFs have higher body mass indices (BMIs) and greater waist circumferences.
Cardiovascular Diseases
The high levels of trans fats, sodium, and added sugars in UPFs contribute to hypertension, dyslipidemia, and other cardiovascular risk factors. UPF consumption has been associated with higher rates of heart disease and stroke, attributed to poor diet quality and the promotion of atherogenic and inflammatory pathways. In the Framingham Offspring Study, an 18-year follow-up revealed that each additional daily serving of ultra-processed foods increased the risk of developing cardiovascular disease (CVD) by 7%. Similarly, the French NutriNet-Santé cohort study found a 12% higher risk of CVD with increased consumption of ultra-processed foods. Meta-analyses provide strong evidence that certain ultra-processed products, such as processed meats and sugar-sweetened beverages, along with nutrients commonly found in these foods, like trans fats and sodium, elevate the risk of CVD. Additionally, epidemiological studies have connected ultra-processed foods to various CVD risk factors.
Diabetes
Diets rich in ultra-processed foods have been implicated in the development of type 2 diabetes. The high glycemic index of many UPFs causes rapid spikes in blood glucose levels, which increases the risk of insulin resistance. Furthermore, the lack of fiber and essential nutrients in these foods exacerbates this risk. Observational studies consistently link ultra-processed food intake with an increased risk of diabetes, with particular emphasis on certain food groups like sugar-sweetened beverages and processed meats. However, there is a notable gap in meta-analyses evaluating the overall risk of diabetes across all ultra-processed food groups. A meta-analysis found that 72% of included studies showed a positive association between ultra-processed foods and diabetes risk. The meta-analysis revealed that moderate intake of ultra-processed foods increased the risk of diabetes by 12%, while high intake increased the risk by 31%.
Cancer
Emerging evidence suggests a link between UPF consumption and certain cancers. Additives, packaging chemicals, and the high calorie content of UPFs may contribute to carcinogenesis. Studies have reported associations between high UPF intake and increased risks of breast, colorectal, and other cancers. The systematic analysis over different time periods reveals a significant positive association between ultra-processed food intake and increased risk of various cancers, excluding prostate cancer, after adjusting for confounding factors. Specifically, higher UPF consumption is linked to increased risks of overall cancer, breast cancer, colorectal cancer, and pancreatic cancer. Additionally, more modest associations were observed for chronic lymphocytic leukemia and central nervous system tumors.
Other Chronic Diseases
Ultra-processed foods have been increasingly linked to various chronic diseases, including hypertension and depression. Studies indicate that diets high in UPFs often contribute to elevated blood pressure due to their high sodium content and poor nutrient profile. Research has shown that individuals consuming more UPFs are at a higher risk of developing hypertension compared to those with lower UPF intake. For example, the Australian Longitudinal Study on Women’s Health investigated the impact of ultra-processed foods on incident cardiovascular disease and hypertension among middle-aged women. The study revealed that those with the highest intake of UPFs (more than 34.2% of total dietary intake) had a 39% increased likelihood of developing hypertension.
Moreover, UPFs have also been implicated in mental health issues such as depression. A study published in the British Journal of Psychiatry highlighted that higher consumption of processed foods, including UPFs, was associated with an increased likelihood of developing depression. The mechanisms behind this association involve nutrient deficiencies and the inflammatory effects of UPFs, which may adversely affect brain function and mood regulation over time. The study underscored that diets rich in fruits, vegetables, and whole grains, which are typically low in UPFs, were inversely associated with depression risk.
Similarly, a study conducted among non-Hispanic White females found that compared to individuals with the lowest quintile of ultra-processed food consumption, those in the highest quintile showed an increased risk of depression as indicated by both strict (HR 1.49; 95% CI 1.26-1.76; P < 0.001) and broad definitions (HR 1.34; 95% CI 1.20-1.50; P < 0.001). Also, comparing the highest and lowest quintiles, the study found that only artificially sweetened beverages (HR 1.37; 95% CI 1.19-1.57; P < 0.001) and artificial sweeteners (HR 1.26; 95% CI 1.10-1.43; P < 0.001) were significantly associated with an increased risk of depression.
Public Health Measures in Nepal
To reduce the consumption of ultra-processed foods, it is essential to combine education, policy, and community initiatives. Launching public campaigns and incorporating nutrition education in schools can raise awareness about the health risks of ultra-processed foods. Implementing clear labeling on food packaging, restricting advertising, and introducing taxes on these foods can further discourage their consumption. Promoting healthy alternatives through subsidies for fresh foods and supporting farmers' markets can make nutritious options more accessible. Community initiatives like establishing community gardens and offering cooking classes can encourage healthier eating habits.
Additionally, encouraging workplaces, schools, and hospitals to provide healthy food options and replacing ultra-processed snacks in vending machines can create supportive environments. Promoting home cooking through meal planning and sharing nutritious recipes, along with working with retailers to prioritize healthier foods and designing urban areas that support access to fresh food markets, can collectively help shift dietary habits towards healthier choices.
Conclusion
Ultra-processed foods pose significant health risks across various chronic diseases, including obesity, metabolic disorders, diabetes, heart diseases, hypertension, cancer, and depression. Studies consistently demonstrate that higher consumption of UPFs correlates with elevated odds of developing different chronic diseases. These findings underscore the detrimental impact of UPFs on both physical and mental health outcomes. To address these challenges, effective public health measures are crucial, including educational campaigns, nutritional interventions in schools, clear food labeling, restrictions on advertising, and taxation of UPFs. Promoting access to fresh foods, supporting community-based initiatives, and fostering environments conducive to healthier dietary choices are essential steps towards mitigating the adverse health effects of UPFs on a population level in Nepal.
Article was jointly Authored by Dr. Suman Paudel and Ms. Rojina Basnet !!!