An Interesting, Alarming Look at Ultra-Processed Foods

UPFs, or ultra-processed foods—like packaged snacks, sugary drinks, instant meals and fast food—are often renowned for their convenience, low cost and pleasant taste, but they could be taking a major toll on our health, even more than we once thought. Today, I am sharing an interesting study I came across, supported by the Intramural Research Program of the National Institutes of Health, National Institute of Diabetes & Digestive & Kidney Diseases, which demonstrated the negative effects of UPFs on our health.
 
I was particularly intrigued when this nutrition-based RCT (randomized controlled trial) surfaced within the current discussion around UPFs. Nutrition research is rarely conducted as an RCT, resulting in a mountain of conflicting observational studies where associations between variables are identified but causation cannot be drawn. The lack of RCT makes nutrition research particularly confusing and is often compounded by publication bias, media interpretation, reductionist thinking and self-interest.
 
Note that the generalizability of this study is limited due to the lack of consumer choice and the in-patient nature of the study design. Further, the sample size was small, the time in each study group was short and a washout period between groups was absent. But the implications remain interesting and something to consider when we make choices about what we’re consuming.
 
(Keep in mind, this study is from 2019, so its discussion around UPFs precedes the current political climate.)
 
Let’s take a close look at this study and the findings:
 
THE VARIABLES:
The study examined 20 weight-stable participants: 10 males and 10 females aged 18-50, all who were admitted to the NIH Clinical Center for a continuous 28-day period. For a two-week period, participants were randomly assigned a UPF diet (as defined by NOVA) or an unprocessed diet. After two weeks, without a washout period, they switched diets. All 20 participants completed the study.
 
Each participant was provided with three meals a day. The weekly per-person costs of these diets were estimated to be $106 for the UPF diet and $151 for the unprocessed diet. The foods presented among the two diet groups were matched for calories from sugar, fat, sodium, fiber and macronutrients. Participants were instructed to eat as much as they wanted within a one-hour window for each meal. Snacks were also made available for each diet group.
 
MEASURING THE VARIABLES:
Participants wore continuous glucose monitors (CGMs) to track glucose, accelerometers to track energy expenditure (calculated as METs), and spent one day a week in a respiratory chamber to track energy components. Fasting blood was drawn at baseline and on the final days in each diet group.
 
Participants also responded to surveys assessing appetites, sensory experience and palatability.
 
To offset deconditioning from sedentary behavior, participants performed three, 20-minute cycle sessions at a controlled intensity.
 
THE OUTCOMES:
While on the UPF diet, participants consumed 500 more daily calories per day than when on the unprocessed diet, which correlated with an increase in calories consumed per minute in the UPF diet group. The extra calories consumed were from carbohydrates and fat (notably, not from protein).
 
Not surprisingly, participants showed increases in weight and body fat mass when on the UPF diet and reductions in weight and body fat mass when on the unprocessed diet. While on the UPF diet, fat oxidation was reduced, while insulin secretion and blood glucose increased.
 
While on the unprocessed diet, appetite-suppressing hormone PYY levels increased, along with free fatty acids and free T4, while hunger hormone ghrelin, adiponectin, total cholesterol, hsCRP and Total T3 levels decreased.
 
UPFs AND BRAIN HEALTH
Last month, in Concierge Choice Physicians members’ only wellness program, Motivated Mondays, CCP closely examined the role of UPFs on cognitive health. UPFs have been associated with a number of health concerns, including cardiovascular disease, diabetes, and mental health disorders. In this study, a well-controlled RCT, we see it corresponding in a linear, stepwise fashion with weight gain via increased calorie consumption. In addition, even in the short term, the biomarkers hint at the potential for additional inflammatory and metabolic health concerns.
 
WHAT ALL OF THIS MEANS FOR US:
With all this in mind, strongly I encourage you to eat and identify real, unprocessed food.
 
To help, you can ask yourself the following three questions we should ask ourselves before adding a food item to our grocery baskets:
 

1. Did my grandmother eat this food?
2. Could I recreate this food at home in my kitchen?
3. Are the ingredients on this label available right here in the grocery store?

 
If your answer is no to any of the above questions, try to avoid it.
 
As your concierge physician, I am always available to you, especially when it comes to helping you make healthier choices. Feel free to reach out with your individual questions.