In this blog we have published several articles commenting on some studies and reviews that have analyzed the relationship between ultra-processed food and health from different perspectives (example, example). These works reached unfavorable results for this type of products, which have subsequently been confirmed in other studies, such as in the review «Consumption of ultra-processed foods and health status: a systematic review and meta-analysis» (2021), in which the authors concluded that its consumption is associated with a worse cardiometabolic risk profile, a higher risk of cardiovascular disease, cerebrovascular disease, depression and mortality.
But since the main topic of this blog is weight loss, we were waiting for specific reviews on this topic. Reviews that have finally arrived in the form of two systematic reviews of observational studies and that we will discuss below.
The first of them, titled «Consumption of ultra-processed foods and obesity: a systematic review» (2021), was published several weeks ago in the journal Nutrición Hospitalaria, synthesizing the results of 12 observational studies. It can be downloaded in full from this link and it is in Spanish, which makes it especially interesting for those who cannot speak English.
The authors’ conclusions were the following:
«This systematic review provides evidence on the relationship between the consumption of ultra-processed foods and the prevalence and incidence of obesity. However, the different methodologies used and the various food classification systems drive the need for more studies, preferably in longitudinal cohorts, to corroborate the results. It is also advisable that more health and disease parameters be taken as reference, in addition to BMI, and it would be desirable that a single food classification system be established.
There are many factors that influence the nutritional status of the population, but the eating pattern followed is decisive. Furthermore, frequent consumption of ultra-processed foods is usually linked to a sedentary lifestyle and habits that are harmful to health.
Given that the choice of foods to consume is decisive for maintaining a good state of health and avoiding obesity and aging (37), it seems essential to develop strategies to educate the population so that they can choose judiciously the type of foods they consume. . . «The marketing of ultra-processed foods, as well as sometimes their low price, facilitates quick purchases and makes this task very difficult.»
That is, a positive relationship was found between ultra-processed foods and overweight, although researchers consider that the evidence is still scarce.
The second investigation is from just a few days ago, «Consumption of ultra-processed foods and risk of obesity in adults: a systematic review and dose-response meta-analysis» (2021), another systematic review with meta-analysis that also summarizes the results of 12 observational studies. The authors summarize their conclusions as follows:
«The consumption of ultra-processed food was associated with a higher risk of obesity (OR = 1.55), overweight (OR = 1.36), and abdominal obesity (OR = 1.41). Furthermore, for every 10% increase (in calories) of ultra-processed food in daily intake is associated with a 7%, 6% and 5% higher risk of overweight, obesity and abdominal obesity, respectively. The dose response meta-analysis of cross-sectional studies showed a Positive linear association between the consumption of ultra-processed food and abdominal obesity.
Our study suggests that the consumption of ultra-processed food is associated with an increased risk of overweight and obesity. abdominal.»
This following meta-analysis includes the graphs, with the curves calculated for the relationships found, which help visualize them:
In summary, it seems that studies are confirming the relationship between the intake of ultra-processed food and higher body weight. Something that was expected for the majority, although it seems not so much for those who wrote the recent official Spanish dietary recommendations.
If you want to know what type of foods scientists are referring to exactly when they study ultra-processed food, you can read this previous post, which includes an infographic explaining it. And if you are wondering about the reasons why this type of food is unhealthy, I recommend reading the ideas and reflections in this other post.
