Cut Ultra-Processed Foods, Double Your Weight Loss?

This was just one of many headlines that hit the health news last week. Here's the CNN Headline: Eating Minimally Processed Meals Doubles Weight Loss Even When Ultra-processed Foods are Healthy, Study Finds

Doubling? That sounds Amazing! Huge! We should ban UPF’s and everyone will lose weight! But wait a minute. What does doubling the weight loss mean? This “doubling” is deceptive. Over the course of the 8-week study, the people on the minimally processed diet lost 2% of their body weight. The people on the healthy ultra-processed diet lost 1% of their body weight. So, let’s say the average weight going into the study was 200 pounds. That’s 4 versus 2 pounds. 4% is double 2%. So, it’s technically accurate but it’s leaving out the true meaning.

As with many click-bait headlines, you must read the whole article to, maybe, get the whole truth. The rest of the article from CNN does a good job of laying out all the details and nuances of this study. But you’ve got to read past the headline.

If you read several paragraphs into this CNN headline, you’ll get a clearer picture of the whole truth: The weight loss from minimally processed food in the new study was modest — only 2% of the person’s baseline weight, said study first author Samuel Dicken, a research fellow at the department of behavioral science and health and the Centre for Obesity Research at University College London.

But let’s give credit where credit is due. This was a well-designed study – a randomized controlled trial. It’s a much stronger design than what you typically see in nutrition research. And, the study was short – just 8 weeks. So that minor differences in actual weight loss could be higher and more meaningful over time. Both diets had to follow the UK’s Eatwell Guide. The people in the study were given meals and snacks over the course of the study.

One of the most interesting findings is that the people on the healthy ultra-processed diet didn’t gain weight – and in fact lost some. They ate 120 fewer calories a day, thus losing a small amount of weight. People on the minimally processed diet, however, ate 290 fewer calories a day, thus losing even more weight and some body fat as well.

What I Can Honestly Tell You About Ultra-Processed Foods:

The Classification System is Faulty

o   Foods are classified solely based on their level of processing.

o   Nutrient Content is not considered.

o   So, foods like whole grain commercial breads and vanilla yogurt are classified as UPF’s.

o   We do not have a clear, understandable definition of UPF’s.

o   Some UPF’s are high in key nutrients like fiber, vitamins, and minerals. UPF’s are Convenient

o   Convenience is a major factor in many people’s food choices.

UPF’s Taste Good

o   They’re high in fat, sugar, salt, and low in fiber, so they are tasty! You remember that old potato chip slogan? You Can't Eat Just One!

People are More Likely to Overeat UPF’s

o   One study (a well-done, tightly controlled study) showed that when given a diet high in UPF’s, people ate 500 calories a day more than people on a minimally processed diet.

The Bottom Line? Reducing UPF’s is a good idea and good for your health. But, I recommend choosing foods based on their nutrient profile and quality rather than level of processing. We'll talk about what some of those key nutrients are in the coming weeks!

Beth Kitchin PhD RDN