Diet Swap Study Reveals How Ultra-Processed Foods Can Derail Weight Loss

Gizmodo

4 days ago

In case you needed more incentive to cut down on ultra-processed foods, a new diet swap study out today reveals that people experienced greater weight loss while eating minimally processed foods than they did when they ate a nutritionally similar, ultra-processed diet.
In a six-month trial led by scientists at University College London, study participants were assigned one of the two diet regimes to follow for eight weeks, and then took a four week break before swapping to the other diet for another eight weeks. Participants lost more weight while eating the minimally processed diet than the ultra-processed one; they also shed more unhealthy fat. The findings, published Monday in Nature Medicine, suggest that, among other things, ultra-processed diets are especially good at stoking people's food cravings, the researchers said.
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Although there is some debate over what constitutes an ultra-processed food, there are generally considered products or ingredients that have gone through high levels of industrialized processing, like breakfast sausages, candy, or sodas. There is a growing mountain of evidence that suggests a diet rich in ultra-processed foods is less healthy overall than a diet made up of mostly whole foods, and that ultra-processed foods may raise the risk of certain diseases. Most of this research, however, only shows a correlation between ultra-processed diets and poorer health outcomes, and not a direct cause-and-effect link. Clinical trials can provide stronger evidence, but they're notoriously difficult to do in the world of nutrition science for many reasons, particularly funding, the researchers said.
A New Diet Study Confirms Your Worst Suspicions About Ultra-Processed Foods
The results highlight the importance of following government dietary guidelines, Dicken said. But the study also indicates that people who want to lose weight may see the most benefit from sticking to minimally processed foods. As to why the ultra-processed foods are worse for dieting, the researchers have their educated guesses.
Ultra-processed foods tend to have more appealing textures and artificially boosted flavors, which often means they are softer or easier to eat, and tastier. Their appearance and packaging might also make them more visually appealing to potential customers. Interestingly, the volunteers in this study reported that both diets were equally satisfying to eat on average, but they also reported having better control over their cravings while on the minimally processed diet. Dicken noted that the researchers weren't able to directly test these potential explanations in this trial, though, so more research is needed to know for sure.
The team has already launched their next study, which is testing out a behavioral support program to reduce people's intake of ultra-processed foods. But Dicken cautioned that it will take widespread societal shifts, not individual scolding, to change our collective diets for the better.