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Introduction
Discussions around ultra-processed foods (UPFs) and their role in public health have gained significant traction in recent years. While some advocate for categorizing and regulating these foods due to their potential negative health effects, others argue that such classifications can oversimplify the issue and detract from more actionable dietary changes.
In this episode, Dr. Duane Mellor, a registered dietitian and researcher, joins us to explore the complexities of the UPF debate. Rather than dismissing the concept outright, Dr. Mellor emphasizes the importance of nuanced discussion, bridging the gap between research findings and practical, evidence-based dietary guidance.
Throughout this conversation, we unpack the broader implications of ultra-processed foods in the food system, consider how added fat, salt, and sugar contribute to public health challenges, and explore realistic approaches for dietary improvements.
Related resources
- Join the Sigma newsletter for free
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- Enroll in the next cohort of our Applied Nutrition Literacy course
- Paper: Mellor, 2024 – The role of food science and technology in navigating the health issues of ultra-processed foods
- [03:02]Interview start
- [06:39]Understanding the NOVA classification
- [09:53]Potential pitfalls and policy implications
- [14:52]Food science and technology perspectives
- [20:47]Challenges in food classification
- [26:13]Health equity and policy considerations
- [42:31]Communication and public perception
- [50:30]Final thoughts and advice
- [51:15]Key ideas segment (Premium-only)
Guest Information
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Dr. Mellor is currently working in clinical dietetics, working to support people, families and carers living with diabetes.
Previously Dr. Mellor worked in medical education at Aston University, holding the position of Associate Dean for Public Engagement in the College of Health and Life Sciences.
After initially working in the areas of clinical trials, Dr. Mellor’s other research interests focused on improving nutrition and health by working with communities to celebrate their heritage through food and help tackle barriers resulting from societal inequalities.
Danny Lennon has a master’s degree (MSc.) in Nutritional Sciences from University College Cork, and he is the founder of Sigma Nutrition.
Danny is currently a member of the Advisory Board of the Sports Nutrition Association, the global regulatory body responsible for the standardisation of best practice in the sports nutrition profession.
Useful Terminology
● Ultra-Processed Foods (UPFs) – Industrially formulated foods that undergo multiple processing steps and often contain additives, flavour enhancers, or extracted ingredients. They tend to be ready-to-eat products high in added sugar, fat and/or salt, with little intact whole food content.
● NOVA Classification – A food classification system that groups foods by their level of processing, from Group 1, unprocessed or minimally processed foods, to Group 4, ultra-processed foods. NOVA Group 4 foods include products such as sugary drinks, packaged snacks, instant noodles and reconstituted meat products.
● Food Matrix – The physical structure and organisation of nutrients and compounds within a food. A food’s matrix, such as the fibrous cell walls in fruits or nuts, affects digestion and absorption. Intact natural matrices usually slow digestion and promote satiety, whereas heavy processing can disrupt the matrix and make calories more rapidly available.
● Emulsifiers – Substances added to processed foods to improve texture, consistency or shelf-life by allowing ingredients such as oil and water to remain mixed. While many additives are deemed safe, there is ongoing research into whether certain emulsifiers may alter gut bacteria or intestinal health.
● Energy Density – The amount of calories per gram of food. Ultra-processed foods are often energy-dense due to added sugars and fats, meaning they can deliver many calories in a small volume. Foods lower in energy density, such as fruits and vegetables, tend to be more filling per calorie.
● Palatability – The taste appeal of food, often enhanced in UPFs through combinations of sugar, fat, salt and flavourings. Hyper-palatable foods are engineered to be extremely enjoyable and easy to eat in large quantities, which can increase the risk of overeating.
● Eating Rate – The speed at which food is consumed, often expressed as calories per minute. Many UPFs are soft, convenient and easy to eat quickly, which may allow people to consume more energy before fullness signals have time to develop.
● Satiety – The feeling of fullness and satisfaction that suppresses further eating after a meal. Satiety is influenced by factors such as protein, fibre, food volume, food texture, eating speed and the physical structure of the food.
● Food Reformulation – The process of changing food products to improve their nutritional profile, such as reducing salt, sugar or saturated fat, increasing fibre or protein, or altering texture to reduce energy intake rate.
Defining Ultra-Processed Foods and the NOVA System
Ultra-processed foods are products that are extensively processed and formulated, usually in industrial settings. They typically contain ingredients not commonly used in home cooking, such as modified