Minimizing overly processed foods is crucial for reducing chronic inflammation and the risk of related diseases. However, figuring out what qualifies as “processed” can be confusing. Some processing methods actually enhance food’s nutritional value.
Dr. Walter Willett, professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health, explains, “When done well, some processing can preserve nutrients or improve accessibility, particularly with seasonal produce. It can also enhance food safety, like pasteurization, or improve healthfulness through fermentation, as with yogurt.”
The key is understanding when processing becomes detrimental and which processed foods to avoid.
Understanding Processed Foods
Processed foods are those altered from their natural state. This can range from simple actions like chopping and freezing vegetables to removing inedible parts, such as shells from nuts. These are considered minimally processed.
The next level includes foods with a few added ingredients. Examples include a basic cracker (wheat, oil, salt), freshly baked bread, or canned vegetables in water and salt.
“Ultra-processed” foods undergo more extensive changes. Dr. Willett clarifies, “Ultra-processing often obscures the original food’s form and involves additives like preservatives, oils, sugar, salt, coloring, and flavoring. This is often what we consider junk food.”
Examples of ultra-processed foods are hot dogs, deli meats (see “The Dangers of Processed Meat”), cheese puffs, doughnuts, frozen pizza, white bread, cookies, microwaveable dinners, and soda.
Alt: Woman examining a nutrition label on a refrigerated food product in a grocery store, illustrating how to tell if a food is processed.
The Dangers of Processed Meat
Processed meats rank among the least healthy food choices. Examples include bacon, sausage, ham, hot dogs, salami, and deli meat. They are typically high in salt, unhealthy saturated fat, nitrates, nitrites, and other chemical additives.
Regular consumption of processed meats is linked to increased risks of cardiovascular disease and colorectal cancer. A 2019 study in the International Journal of Epidemiology involving nearly 500,000 participants revealed that those consuming red or processed meat four or more times weekly had a 20% higher risk of developing colorectal cancer over a five-year period compared to those consuming it less than twice a week.
The International Agency for Research on Cancer, a part of the World Health Organization, classifies processed meat as carcinogenic to humans, specifically concerning colorectal cancer.
Health Risks Associated with Ultra-Processed Foods
When health experts warn against processed foods, they generally refer to ultra-processed options. These foods pose health risks for several key reasons.
Dr. Willett notes, “Processing often diminishes a food’s nutritional value, such as refining whole grains. It can also introduce harmful elements like trans fats or excessive amounts of salt and sugar.”
A diet high in ultra-processed foods is associated with an increased risk of chronic inflammation, various chronic diseases (heart disease, diabetes, inflammatory bowel disease, obesity, and cancer), and even premature death.
A 2019 BMJ study following over 105,000 individuals for five years showed that each 10% increase in ultra-processed food consumption correlated with a 12% increase in the risk of heart attack or stroke. Another 2019 BMJ study, involving almost 20,000 participants followed for an average of 10 years, found that consuming more than four servings of ultra-processed foods daily was associated with a 62% higher risk of mortality from any cause, compared to consuming two servings per day.
How to Tell If a Food Is Processed: Identifying Ultra-Processed Foods
Ultra-processed foods are generally easy to identify by their lengthy ingredient lists. They are commonly found on store shelves, in freezers, refrigerated sections, delis, and bakeries. Common examples include packaged, ready-to-eat meals, prepared side dishes, snacks, and sweets like cookies and cakes.
However, some ultra-processed foods deceptively appear healthy. This is especially true for fruit-flavored yogurts, refrigerated soups, refrigerated pastas, granola bars, juices, breakfast cereals, frozen yogurt, low-fat salad dressings, condiments, butter substitutes, low-salt crackers, and nut butters that are ultra-processed.
So, How To Tell If A Food Is Processed? The best method is to carefully examine the ingredient list. If you notice numerous ingredients, including chemicals and unrecognizable words, the food is likely ultra-processed. Opt for products with the shortest, most recognizable ingredient lists possible.
Occasional Indulgence: Is It Ever Okay to Cheat?
Avoiding ultra-processed foods entirely can seem challenging, particularly when you need convenient options or want to enjoy treats like muffins or deli sandwiches. Is it acceptable to occasionally “cheat” if you generally maintain a healthy diet?
“Almost anything is okay if you break the rules just once a month,” Dr. Willett advises. “However, pay attention to other ingredients. For instance, a ragù could be acceptable if the salt content is below 200 milligrams per serving.”
Other helpful guidelines: Limit your total daily salt intake to below 2,300 mg, unless your doctor recommends a lower amount. Saturated fat should comprise no more than 10% of your daily calories. Limit added sugars to a maximum of 24 grams per day for women and 36 grams per day for men.
Prioritize whole, unprocessed foods as part of a predominantly plant-based diet rich in vegetables, legumes, fruits, whole grains, nuts, and seeds.
It’s also important to remember that “Just because foods are unprocessed, it does not mean that they’re healthy,” as Dr. Willett points out. “A diet based on red meat, milk, and potatoes is unprocessed but far from optimal.”
Alt: Headshot of Anthony L. Komaroff, MD, Editor in Chief of Harvard Health Letter, a medical professional who reviewed the article.
Key Takeaways
Identifying processed foods, especially ultra-processed ones, is vital for maintaining health and preventing chronic diseases. Reading ingredient lists carefully, focusing on whole, unprocessed foods, and allowing for occasional, mindful indulgences can help you make informed dietary choices.
