Ultra-Processed Food Won't Make You Fat...At First

Generally, most adults logically understand that their diet should include a higher percentage of “natural” foods versus “unnatural” or industrially-processed items. This is common knowledge, yet Americans consume more ultra-processed foods (UPF) than any nation on the planet. It’s estimated that 60-75% of total energy intake in the U.S. comes from highly processed foods, compared to less than 40% in Europe. 

What constitutes an ultra-processed food? NOVA is an international food classification system, which categorizes foods based on the amount of industrial processing they undergo. According to their definition, ultra-processed foods are “industrial formulations of processed food substances that contain little or no whole foods and typically include flavorings, colorings, emulsifiers, and other cosmetic additives.” 

Essentially, UPFs are foods that are the furthest removed from raw agricultural products. 

Ultra-Processed Foods in the News 

Ultra-processed food intake has become so prevalent, and the body of evidence that it negatively affects health so overwhelming, that the U.S. government is finally considering stricter legislation to regulate the manufacturing and sale of these food items. To this point, America has lagged behind other developed nations including several Latin American and European countries in adding warning labels to UPFs. 

Every five years, the U.S. Departments of Agriculture and Health and Human Services release the Dietary Guidelines for Americans, which provides advice on what to eat and drink to meet nutrient needs, promote health, and prevent disease. These guidelines form the basis of Federal nutrition policy and programs, and have a wide-ranging influence on the food industry in the United States. As of this writing, the Dietary Guidelines Advisory Committee (DGAC) is reviewing the current body of nutrition science research in order to release the Dietary Guidelines for 2025-2030. 

The DGAC comprises 20 nationally recognized nutrition and public health experts, and they are currently examining whether stricter regulations on ultra-processed foods are necessary. As one might expect, this potential regulatory action has food industry lobbyists working overtime to maintain the status quo. 

These efforts have recently led to slanted headlines like this one from the Daily Mail:

“Ultra-processed foods do NOT cause obesity, says U.S. government’s top diet advisors in bombshell review of current evidence: ‘Studies have been biased.’’ -5/31/24

In reality, these top diet advisors were in no way letting UPFs off the hook. Instead, they were simply stating that there is nothing intrinsic about processed foods that causes obesity, and that a caloric energy surplus is still the causal factor for obesity. Meaning, it is entirely possible to consume processed foods and not become obese, as long as one is not entering into a caloric surplus. 

So why is the headline “Ultra-processed foods do NOT cause obesity” so misleading? It’s misleading because it suggests the consumption of UPFs is unrelated to obesity, when there is a significant amount of research suggesting the two are almost surely connected. While it may not automatically result in weight gain, a diet high in UPFs will greatly increase your likelihood of becoming obese. 

Ultra-Processed Foods Drive Overconsumption 

A groundbreaking study published in Cell Metabolism in May 2019 was the first randomized, controlled study to establish causality between ultra-processed food intake and overeating. The researchers found that subjects on an ultra-processed diet ate about 500 calories more per day than subjects on an unprocessed diet. They also found that the processed dieters ate at a faster rate and subsequently gained weight over the study period. 

This study was critical because it established clear evidence of what chemists hired by big food manufacturers have known for decades: ultra-processed foods are designed to be overconsumed. The specific ingredient make-up of these food products appeals to eating behaviors that are hardwired into human DNA, including a strong instinctual drive towards sources of fat, sodium, and sugar. 

Our ancestors sought out these once-scarce nutrients for survival, so we adapted to seek and crave them. From that perspective, it makes sense that it’s damn-near impossible to turn down at least one bite of that donut. It’s not enough for you to simply crave “the foods;” however, once you’re in, the next step is to keep you eating. 

It’s not only about what’s included in ultra-processed foods that leads to overeating, it’s also about what’s (strategically) not included. UPFs are notoriously low in both protein and fiber, two key components of regulating appetite. Protein and fiber lead to increased feelings of fullness and satiety and are major allies against cravings. 

Individuals with highly processed diets often find themselves constantly hungry with widely fluctuating energy levels throughout the day. As a result, they snack on the same foods that created their slump in the first place, and the cycle repeats itself – they continue to eat despite consuming a surplus of calories, and weight gain follows soon after. 

What was that part again about ultra-processed foods not causing obesity? 

From a scientific perspective, a straight line of causality cannot yet be drawn. That said, the most overweight country in the world consuming the highest percentage of industrially processed food in the world is not a coincidence. 

Ultra-Processed Food Regulations in Action 

More than a dozen countries worldwide have adopted some form of front-of-pack-labeling (FOPL) regulations, and there is a growing body of evidence it has an effect on purchasing behaviors related to ultra-processed foods. Perhaps the most successful labeling initiative to date has been in Chilé, where more stringent labeling of UPFs was implemented in 2016.  A 2021 study found a 27% reduction in purchases of foods labeled “high in” sugar in the first year following implementation.

In many Latin American countries, there’s a shared characteristic when it comes to their ability to regulate UPFs: Their respective constitutions guarantee a citizen’s right to health that supersedes commercial free speech. Imagine, prioritizing the health of citizens instead of protecting the interest of corporations as we do here in the United States. 

It remains to be seen whether the 2025-2030 Dietary Guidelines for Americans will lead to substantive change in ultra-processed food labeling practices. Regardless, a call for action in the reform of the United States’ food industry (i.e. promotes citizens’ health rather than harming it) is long overdue.