The degree of processing in our foods matters.

Here’s an example of one reason why.

Ultra-processed foods are talked about a lot on social media, health news outlets, and other media outlets as being unhealthy and something to avoid when choosing what to eat for meals and snacks, but the reasons why aren’t often discussed. We know we should limit our intake of high sugar and high fat ultra-processed foods like sodas, candy bars, chips, and high sugar breakfast cereals, but what about other ultra-processed foods like hummus, protein bars, and ready made meals. Do we need to limit or avoid these foods too

A recent study published in Nature Medicine compared two seemingly healthy diets, one rich in ultra-processed foods, the other rich in minimally processed foods. The study is a first of its kind as there hasn’t been a lot of research into this topic. The main goal was to look at changes in weight when following a “healthy” diet high in ultra-processed foods versus a “healthy” diet high in minimally processed foods. The study was conducted in the UK and followed dietary guidelines of the UK, which are similar to those in the United States. Participants received foods that met the dietary guidelines and allowed for consumption of up to 4,000kcals per day. For 8-weeks they received ultra-processed foods that met these dietary guidelines, then had a 4-week “washout” period before being given a diet meeting the same guidelines but from minimally processed foods for 8-weeks. The results proved to be very interesting. 

To note, all participants were considered overweight or obese but were not instructed to limit or restrict their intake of food. They could eat as much or as little as they pleased from the 4,000 calories of food they were delivered each day. The study was small, but a good first step to learning more about the different ways our bodies respond to ultra-processed foods versus minimally processed foods. One more thing worth noting is that a study conducted in 2019 found that, on average, people consume about 500 calories more per day when eating a diet rich in ultra-processed foods compared to when eating a diet rich in minimally processed foods. The current study being discussed hoped to broaden information on this topic.

Now, onto the results of this latest research. The results showed significant weight loss across both diets, but when following a diet rich in minimally processed foods, participants lost significantly more weight, twice as much weight to be more specific. Other interesting findings included either no significant change or significant improvement in blood pressure, heart rate, and biomarkers on both diets, meaning none of the participants’ health got worse, but some did show areas of improvement or no change at all for blood pressure, heart rate, and other biomarkers. Participants had significantly lower triglyceride levels following the minimally processed foods diet, and conversely, they had significantly lower LDL cholesterol levels following the ultra-processed foods diet. Craving control was also significantly improved on the minimally processed foods diet, leading to fewer calories being consumed. 

So what does all this tell us? It’s an interesting first look into why we should think about limiting our intake of ultra-processed foods when possible. This doesn’t mean we need to avoid ultra-processed foods altogether as the study did show some health improvements when following a diet that meets dietary guidelines, yet is still rich in ultra-processed foods. It is impossible to think we can avoid ultra-processed foods 100% of the time, especially with busy schedules or diet restrictions like lactose-intolerance (soy milk and milk alternatives are ultra-processed foods). 

This is great information to take with us into the future when deciding what to eat for a snack or make for dinner. If we find we are constantly hungry after breakfast, maybe the protein bar we’re having in the morning isn’t the right option for us. Choosing more minimally processed foods, like toast with peanut butter and a banana, could be a better option for keeping us full throughout the morning. 

The key take away should be that we need to start thinking about categories of processing when we choose what to eat, and try to decrease our intake of ultra-processed foods and increase our intake of minimally processed foods. Convenience is great, but we also want to cook our meals and eat whole fruits and vegetables when possible. 

This is also a great first step in getting our national guidelines to include more information and guidance on processed foods consumption. Due to a lack of research in this area, our dietary guidelines do not provide much information on degrees of processing in foods and how much to consume from each category. Hopefully the results of this study will encourage more research and move us in a direction of more guidance and knowledge on the topic.