Understanding Ultra Processed Foods (UPF)
Dr Giles Yeo - Chief Scientific Advisor @ Rio
In a recent episode of "Food for Thought," host Rhiannon Lambert welcomed Dr. Giles Yeo, a geneticist, neuroendocrinologist, and author, to discuss the controversial topic of ultra-processed foods (UPFs), weight loss medications, and the complex factors that influence our eating habits.
The Complexity of Obesity
Dr. Yeo emphasizes that while gaining weight ultimately comes down to consuming more calories than we burn, the path to obesity is far more complex. Our eating behaviors are influenced by genetics, environment, socioeconomic status, and psychological factors. This complexity means that tackling diet-related illnesses requires a holistic approach involving individuals, communities, and governments rather than placing blame on any single factor.
The Ultra Processed Food Debate
One of the most interesting segments focused on ultra-processed foods. Dr. Yeo explains that under the NOVA classification system, approximately 50% of calories in the UK diet come from UPFs - with half of those calories coming from pre-packaged bread alone. While he acknowledges that many UPFs are nutritionally poor, he questions whether the processing method itself is the problem, suggesting that content (salt, sugar, fat levels) might be more important than the manufacturing process.
"I don't see any evidence out there at the moment that the way you make the food, rather than what you add into it, actually makes it bad for you."
The Privilege of Food Choices
A recurring theme throughout the conversation was the privilege associated with food choices. Dr. Yeo highlights that healthier eating is often constrained by three factors: cash, time, and knowledge. Those with fewer resources have fewer choices, which is particularly problematic when healthier foods tend to cost more in terms of both money and preparation time.
Weight Loss Medications
Dr. Yeo also addressed the rise of weight loss injections like Wegovy (semaglutide) or Mounjaro (tirzepatide). He explains that these medications work by enhancing insulin secretion and signaling fullness to the brain, resulting in reduced food intake. While effective (producing 15-20% weight loss over a couple of years), he stresses they should be:
Prescription-only to prevent misuse
Used alongside dietary interventions
Accompanied by increased physical activity to preserve muscle mass
Gender and Genetics
The conversation touched on how genetics influence weight and body composition differently across genders and ages. Dr. Yeo revealed that while there are core genes that affect everyone's weight, there are also distinct genetic signatures that explain why women and men might carry weight differently, and why some people develop obesity in childhood versus adulthood.
Conclusion: A Balanced Approach
Dr. Yeo's final advice offers reassuring simplicity amid the complexity: focus on variety. Rather than labeling individual foods as "good" or "bad," aim for balance over the course of a week. Have you had enough vegetables, protein, and other nutrients? Have you enjoyed some treats too? This balanced approach to eating, combined with an understanding of the many factors influencing our food choices, offers a more sustainable path to health than rigid rules or the latest trends.
