Most people already accept that highly processed foods are not doing us any favours. That questions is closed. Clients know it. Coaches know it. The phrase “ultra-processed” barely raises an eyebrow anymore.
What has changed over the last few years and especially in the last 12–18 months, is how much more we are learning about the mechanisms. The newer research is not simply saying that processed foods lead to weight gain. It is showing how they interfere with appetite regulation, eating behaviour and even the way people tolerate training. These effects often happen quietly, without obvious hunger, cravings or a sense that anything is wrong.
For anyone interested in giving sound, evidence-informed nutritional advice, this is super important. Not as a scare tactic, but as a way to understand why so many clients struggle despite good intentions.
We Thought Calories Were the Whole Story
For a long time, calorie balance sat at the centre of nutritional advice. Energy in, energy out. Eat less, move more. That framework still carries some weight, but it turns out it explains far less of real-world behaviour than we once assumed.
Controlled feeding studies have now shown that people eat more total energy when consuming ultra-processed diets, even when those diets are matched for calories, fat, carbohydrate and protein. The most striking part is that participants do not consistently report greater hunger. They are not describing a loss of control or intense cravings. It’s just that Intake simply drifts upwards.
This challenges the idea that overeating is mainly driven by poor decision-making. In these studies, food availability is controlled, meal timing is standardised and choices are limited. The difference comes from how the food behaves (the metabolic processes) once it is eaten, not from a conscious choice to eat more.
Texture, Eating Speed and Missed Satiety Signals
One of the most consistent findings in recent work is the role of texture. Ultra-processed foods tend to be softer, easier to chew and faster to consume. This has a direct impact on eating rate.
Studies examining meals composed largely of ultra-processed foods show that people eat them more quickly than minimally processed meals. Faster eating reduces the time available for satiety hormones such as GLP-1 and PYY to rise and signal fullness. By the time the body catches up, more energy has already been consumed.
This is not about distraction or mindless eating. Even in laboratory settings, with participants focused on the meal, texture alone changes intake. Chewing, oral exposure time and gastric signalling all play a role. When those signals are shortened or blunted, appetite regulation becomes less precise.
Appetite Regulation Is Easier to Disrupt Than We Thought
Other recent reviews have pulled together evidence showing that ultra-processed foods influence both homeostatic appetite control and reward-driven eating pathways. These foods often combine refined carbohydrates, added fats, flavour enhancers and textures designed for easy consumption. That combination appears to stimulate reward responses while providing weaker satiety feedback.
Over time, this creates a pattern where people eat adequate or excess energy without feeling particularly satisfied. Fullness may arrive late. Hunger may return sooner. None of this feels dramatic. It simply feels normal.
This helps explain why clients often say they are “not that hungry” yet still struggle with fat loss. Appetite is not broken, but the signals guiding it have become less reliable.
Energy Intake Without Awareness
One of the more uncomfortable implications of this research is how invisible the surplus, the extra food consumption, can be. Ultra-processed diets increase intake without a clear subjective warning sign. People do not consistently feel stuffed, uncomfortable or out of control.
Minimally processed meals tend to self-limit intake through volume, fibre, chewing demand and slower digestion. Ultra-processed meals remove several of those signals. As a result, energy density rises, eating speed increases and satiety feedback weakens.
From a coaching perspective, this reframes many “stalled progress” conversations. Clients are often not lying or careless. Their internal feedback is just not giving them accurate information and informing them they’ve had enough.
Training Tolerance, Recovery and Early Drop-Off
Interestingly, nutrition research is starting to link diet quality to training experience rather than just body composition. Diets high in ultra-processed foods often provide less micronutrient density and fibre, alongside a higher inflammatory load in some populations.
Early-phase training appears to be a vulnerable period. The first few weeks of a resistance programme already comes with soreness, fatigue and unfamiliar effort. Appetite dysregulation layered on top of that can reduce recovery quality and increase perceived exertion. Small issues start to compound. Sessions feel harder than expected. Motivation drops.
This does not mean processed foods automatically derail training. It does however, suggest that food structure influences how well people tolerate new training demands, especially during periods where adherence is fragile.
Why “Just Eat Less” Keeps Missing the Mark
Simplistic messaging will always struggle to make an impact because it assumes appetite behaves predictably. The newer evidence shows that food structure alters behaviour before conscious choice becomes apparent. By the time someone considers portion size, the physiological drivers have already shaped intake.
Focusing purely on calorie targets can also obscure why some approaches feel sustainable and others do not. Two diets with identical macros can produce very different lived experiences. Hunger, satisfaction and energy levels are all important factors, particularly for people balancing work, family and training.
This is where conversations around food quality become practical rather than moral. Structure, texture and processing level of the food influence behaviour long before discipline enters the picture.
Talking About Food Quality Without Turning It Into a Lecture
When setting goals with any client, remember, the goal is not perfection. The research does not suggest that every processed food must disappear. The aim is to highlight eating and appetite patterns and make adjustments from there.
Reducing reliance on ultra-processed foods often improves appetite stability without deliberate restriction. Meals are then consumed at a slower rate. Fullness arrives earlier. Eating feels calmer. And you don’t need to track every gram or have a strict meal plan.
For us as coaches, this creates a useful middle ground between rigid dieting and vague advice. Food quality becomes a tool for appetite support rather than a test of commitment.
What This Means for Coaches Giving Nutritional Guidance
Once we understand these mechanisms, the way we talk to clients will change. Instead of framing struggles as non-compliance, they can be framed as predictable responses to food structure. This builds trust and reduces frustration on both sides.
It also provides context for further education. Anyone exploring a nutrition course or a nutrition coach course will increasingly encounter this shift away from calorie-only models and towards appetite regulation, behaviour and adherence. The same themes are now appearing across many fitness courses that aim to prepare coaches for actual client behaviour rather than textbook scenarios.
The Bigger Picture
Processed foods were always part of the problem. The newer research shows they are part of several problems all at once. Appetite regulation, eating speed, satiety signalling, recovery quality and training tolerance all sit downstream of food selection.
None of this means clients need THE perfect diet. It does mean that understanding why food behaves the way it does leads to better outcomes than repeating advice that assumes appetite works like a calculator.
The science is filling in the gaps. When we continue to education ourselves on the latest research, we’re better equipped to help clients stick, adapt and progress without turning nutrition into a constant battle.
Reference
- Hall, K. D., Ayuketah, A., Brychta, R., et al. (2019). Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metabolism. Click here to review the full research article.
- Forde, C. G., Mars, M., & de Graaf, C. (2025). The Effect of Eating Rate of Ultra-Processed Foods on Dietary Energy Intake. American Journal of Clinical Nutrition. Click here to review the full research article.
- European Food Information Council (EUFIC). Eating Rate Has Sustained Effects on Energy Intake From Ultra-Processed Diets. Click here to review the full research article.
- Teo, P. S., Lim, A. J., & Forde, C. G. (2025). The Impact of Ultra-Processed Foods on Hedonic and Homeostatic Appetite Regulation. Appetite. Click here to review the full research article.
- Martínez-Steele, E., Popkin, B. M., Swinburn, B., & Monteiro, C. A. (2023). The Share of Ultra-Processed Foods and the Overall Nutritional Quality of Diets. Public Health Nutrition. Click here to review the full research article.
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