Ready to eat microwave food (TV dinner). Credit: Wikimedia Commons.

A new study that followed the diets of tens of thousands of people for almost a decade found that eating ultra-processed foods was associated with a higher risk of early death. Although this was an observational study, scientists unanimously agree that such products — which include pizza, burgers, and microwave meals — aren’t healthy and should be avoided as much as possible. Instead, people should cook at home or eat out with friends (obviously not in a fast-food restaurant).

Ultra-processed foods comprise 60% of the typical American’s diet

French researchers at the Université Paris monitored the diets of 44,000 individuals between 2009 and 2017. Every six months, participants had to fill out a survey about everything they had ingested within the last 24 hours. Seven years later, the authors registered 602 fatalities, of which 219 were due to cancer and 34 to cardiovascular disease.

Using statistical analysis, the researchers found that the risk of premature death increased by 14% with every extra 10% of ultra-processed foods that individuals included in their diets.

Ultra-processed foods have been significantly altered from their original state, containing salt, sugar, fat, additives, preservatives, and added artificial coloring. They’re usually consumed as snacks, desserts, or ready-to-eat or -heat meals, and their use has risen steadily in the past several decades. According to a 2016 study, nearly 60% of calories consumed by average American come from ultra-processed foods, which have poor nutritional value.

This is just an observational study and the fact that the participants’ diets were self-reported is an important limiting factor. Nevertheless, it all makes sense, since ultra-processed foods have been previously linked to obesity, cancer, and high blood pressure. In their study, the authors note that additives, packaging, and the processing itself may explain the heightened risk of premature death.

The authors recommend that people avoid ultra-processed foods by cooking at home or eating out. Studies have shown that people who dine together have healthier eating habits, such as enjoying more vegetables, fewer soft drinks, and less deep-fried food.

Ultra-processed foods, however, are pretty hard to resist. For one, it’s very convenient to throw a pizza in the microwave and having your meal ready in 5 minutes. Such products are also cheap, meaning that their negative health outcomes disproportionately affect the poor.