I was standing in front of my pantry last week, holding a protein bar in one hand and a bag of oats in the other, wondering if I was making the right choice. Sound familiar?
We hear ultra-processed foods are bad for us. We also hear that no food is inherently good or bad — it all comes down to what you eat overall. So which is it?
A recent randomized crossover study put the question to the test.
The Study
Researchers recruited 55 overweight or obese adults and split them into two diets: ultra-processed or minimally processed. Each diet lasted 8 weeks, followed by a 4-week washout period, then participants switched to the other diet for another 8 weeks.
Both diets followed the UK’s Eatwell Guide — think of it as the British equivalent of MyPlate — and matched on calories, macros, fiber, sodium, saturated fat, and fruit-and-vegetable intake. The only difference: how much industrial processing the food went through.
The minimally processed group ate whole fruits, vegetables, legumes, plain meats, eggs, and whole grains. The ultra-processed group had sweetened yogurts, packaged cereals, reconstituted meats, ready meals, snack bars, and diet soft drinks.
Participants ate at home and chose their own portions — no one told them how much to eat. They provided all their meals and self-reported what they consumed.
The Results
The minimally processed diet produced greater weight loss: -2% of body weight versus -1% for the ultra-processed group. Only the whole-food diet significantly reduced fat mass, body fat percentage, and visceral fat — though the changes were modest (body fat percentage dropped by just 0.76%).
Here is the part that matters most: daily energy intake was about 330 calories lower on the minimally processed diet. That is a meaningful deficit.
Both diets improved triglycerides, glucose, and cholesterol — but improvements were relatively small and similar between groups.
The Takeaway
An ultra-processed diet is not necessarily bad for your health or body composition — as long as it follows general nutrition guidelines. The catch? Even a “healthy” ultra-processed diet tends to make you eat more, which adds up over time.
My notebook says: texture and ease of eating matter. Ultra-processed foods are designed to be easy to consume. That convenience can quietly push your calorie intake higher without you noticing.
Do your best to prioritize whole foods most of the time. And don’t stress if a snack bar or ready meal fills in the gaps — especially when your overall diet is on track.
Your Move:
- Start today: swap one ultra-processed item for a whole-food version at your next meal (oats instead of cereal, an apple instead of a snack bar).
- Aim for this week: notice whether you feel full sooner when eating minimally processed foods. Keep a simple tally in your notes app.
- Try this month: if most of your meals lean whole-food but some are ultra-processed, that is more than enough progress. Consistency beats perfection.