Unprocessed Vs Processed Diets
Why What We Eat Is Changing How We Feel, Think, and Function
Reviewed by Dr. Peter Rawlek, MD, Dr. Valena Wright, MD and Dr. Scott Rollo, PhD
What Does “Processed” Really Mean?
Any food that has been altered from its original state is technically processed. But that definition alone misses the point. We strip out what makes food healthy, its fibre, structure, and micronutrients that support normal physiology, and are left with something that delivers immediate impact but carries long-term consequences.
The real question is this:
How much has been processed out?
At some point, food stops being food in function. It becomes a product, stripped of its natural structure, fibre, and regulatory properties. What remains is energy that enters the body quickly, with very little control.
Ultra-Processed Foods: Designed for Ease, Not Physiology
Ultra-processed foods are not just convenient. They are engineered.
They are designed to:
Be opened and consumed instantly
Require minimal chewing or effort
Deliver quick, concentrated energy
Stimulate reward pathways in the brain
These foods combine sugar, salt, and fat in ways that make them highly appealing and easy to overconsume. They are not neutral. They are designed to be repeatedly chosen.
What Happens Inside the Body (The Physiology)
When food retains its natural structure, especially fibre, energy enters the system slowly. The body can regulate it. BUT when that structure is removed, energy enters quickly. Blood sugar rises rapidly. Insulin is released to bring it down. Energy drops. Hunger returns.
This is not a theory. It is a predictable physiological sequence.
In the short term, this affects:
Energy levels
Focus and attention
Mood and reactivity
In the day, it shows up as difficulty concentrating, irritability, and fluctuating energy.
Over time, repeated exposure to this pattern changes how the body manages energy. It promotes fat storage, reduces metabolic flexibility, and contributes to long-term conditions such as type 2 diabetes and cardiovascular disease.
This is not about one meal. It is about the pattern.
The Fibre Gap: What’s Missing Matters Most
One of the most important losses in processed foods is fibre. Fibre slows digestion. It stabilizes blood sugar. It feeds the gut microbiome. It regulates hunger and fullness.
When fibre is removed, those regulatory systems are lost. The body is no longer in control of how energy enters. It is forced to react. The natural controls that once regulated how food entered and was processed by the body are no longer present.
Why These Foods Are Easy to Overeat
Ultra-processed foods are hyperpalatable. They activate reward pathways in the brain and are easy to consume quickly. At the same time, they do not produce strong satiety signals.
So two things happen:
The brain is stimulated to keep eating
The body does not signal fullness effectively
This combination makes overeating easy, often without awareness.
What This Means for Daily Life
This is not abstract.
It shows up as:
Midday energy crashes
Difficulty focusing
Increased irritability when hungry
Cravings for quick, sugary foods
These are physiological responses to how energy is entering the system.
What Actually Works
This is not about eliminating all processed foods. That is not realistic. It is about improving the pattern.
Start here:
Choose foods that still require chewing
Include fibre-rich foods at each meal
Aim for half your plate to come from whole, plant-based foods
Add before you subtract
It is not about perfection. It is about progression.
Final Thought
Food is not just fuel. It naturally carries instructions in all its ingredients to the body. Process them out and you have a by-product not a food source.
The more we remove structure and fibre, and the associated micronutrients that accompany these, the more we remove the body’s ability to regulate itself. The more we preserve it, to be unprocessed, the more we support stability, clarity, and long-term health.
Start with what’s on your plate. What is on your plate?
Reference:
Hall, K. D., Ayuketah, A., Brychta, R., Cai, H., Cassimatis, T., Chen, K. Y., … & Zhou, M. (2019). Ultra-processed diets cause excess calorie intake and weight gain: An inpatient randomized controlled trial. Cell Metabolism, 30(1), 67–77. https://doi.org/10.1016/j.cmet.2019.05.008
Monteiro, C. A., Cannon, G., Levy, R. B., Moubarac, J. C., Louzada, M. L. C., & Jaime, P. C. (2019). Ultra-processed foods: What they are and how to identify them. Public Health Nutrition, 22(5), 936–941. https://doi.org/10.1017/S1368980018003762
Reynolds, A., Mann, J., Cummings, J., Winter, N., Mete, E., & Te Morenga, L. (2019). Carbohydrate quality and human health: A series of systematic reviews and meta-analyses. The Lancet, 393(10170), 434–445. https://doi.org/10.1016/S0140-6736(18)31809-9
Barber, T. M., Kabisch, S., Pfeiffer, A. F. H., & Weickert, M. O. (2020). The health benefits of dietary fibre. Nutrients, 12(10), 3209. https://doi.org/10.3390/nu12103209
Ludwig, D. S. (2011). Technology, diet, and the burden of chronic disease. JAMA, 305(13), 1352–1353. https://doi.org/10.1001/jama.2011.380
Fardet, A. (2016). Minimally processed foods are more satiating and less hyperglycemic than ultra-processed foods: A preliminary study. Food & Function, 7(5), 2338–2346. https://doi.org/10.1039/C6FO00107F
Slavin, J. (2013). Fiber and prebiotics: Mechanisms and health benefits. Nutrients, 5(4), 1417–1435. https://doi.org/10.3390/nu5041417