What Could Happen To Your Body If You Cut Down On Ultra-Processed Foods?

What are UPFs and how much are we eating?

Recent data from a study by the Johns Hopkins Bloomberg School of Public Health shows that more than half of all calories consumed in US homes come from UPFs. This includes all the obvious things that probably come to mind when you think of “processed food” – your burgers, hot dogs, potato chips, and cakes – but most widely accepted definitions of the term also cover some more surprising foods. 

Things like infant formula and store-bought loaves of bread can also count as UPFs due to their combinations of numerous ingredients and additives like emulsifiers. These foods are considered a step further than processed foods, which are things like canned fish and pasteurized milk – a type of processing that is essential for safe consumption, whatever the tradwives on TikTok want to tell you. 

It can be easy to lump everything that can technically be designated a UPF under one umbrella, but we should also consider everything else we know about what constitutes a healthy diet. For example, someone may consume cereal – a UPF – for breakfast but then eat mostly veggies and wholegrains for the rest of the day. Does that mean their diet is “unhealthy?” Nuances like this mean this topic is not as simple as some would like to suggest. 

What did the study authors do?

What most people agree on, though, is that the average proportion of UPFs in many diets is still too high. Not all UPFs have an unfavorable nutritional profile, but as Dr Alison Brown of the National Heart, Lung, and Blood Institute pointed out in a recent statement, “There’s a lot of overlap between ultra-processed foods and those that are high in saturated fat, added sugar, and sodium”.

As a way of tackling the issue, the authors of the new study set out to test “the feasibility, acceptability, and preliminary efficacy of a novel behavioral intervention designed to reduce UPF intake.”

The participants were aged between 18 and 75 and had already expressed a desire to change their eating habits. They all reported consuming at least two UPFs per day, and four different UPFs in the previous week. The total sample, which was small at just 14 people (one of whom dropped out after session one), was 85.7 percent female. All participants were classed as overweight or obese and had indicated a desire to lose weight. 

Over an eight-week program, the group attended weekly meetings with a lifestyle coach, covering themes like meal planning, food cravings, and mindfulness. There were also four 30-minute practical sessions on meal prep, based on a UPF-free menu.

To help kickstart their lifestyle adjustments, they were all given $100 to spend on groceries of their choosing, with the coach encouraging them to opt for unprocessed whole foods. 

Before and after the intervention, the participants all self-reported their body weight, and were periodically asked for feedback on how the program was going. 

At the end of the study, all remaining participants said they were “satisfied” or “very satisfied”, and all believed they were eating fewer UPFs. They reported losing an average of 3.5 kilograms (7.7 pounds) during the eight weeks, and their total daily calorie intake went down by an average of about 612. 

“[The coach] gave us all kinds of recipe ideas that my wife and I really liked, and it just turned us on to all these foods we didn’t know before, and ways to prepare foods and make them taste excellent,” one participant reported. 

What’s the takeaway?

The authors say this study was among the first to test this kind of behavioral intervention, and that it shows such a program is feasible and a positive experience for the participants. 

However, there’s no getting away from the small sample size, which the authors acknowledge: “The most notable limitation of this pilot study was its small sample size; results should be interpreted with caution and cannot be assumed to be generalizable.” Other limitations include the fact that weight data was self-reported, which is always prone to bias. 

It’s notable also that this population of people had already expressed a wish to change their eating habits. It’s not clear whether such a program would work for people who have not previously shown an interest in this. We also don’t know how the participants will fare in the long term after the program is done. 

One other great point raised by the authors is the need for more systemic change, if governments and health authorities are really serious about reducing the proportion of UPFs in our diets: “To reduce UPF intake on a broad scale, integrated approaches that combine individual-level interventions with broader public health policies are needed.”

Ultimately, this is a pilot study. It’s possible that a structured intervention like this could be very helpful for individuals looking to decrease their own consumption of UPFs, and there did appear to be positive physical and psychological effects for this group of participants. But it’s a long way from a generalizable result that can be applied to the broader population.

The development of UPFs and their rise to prominence in the Western diet has been in process over several decades; it’s probable that this new reckoning with what that means for us, and the efforts to rethink our food system, will also be a long game.  

The study is published in the journal Obesity Science and Practice.