Minimizing overly processed foods in your diet is crucial for preventing chronic inflammation and related diseases. However, determining what constitutes a “processed food” can be tricky. Some processing methods actually enhance food’s nutritional value and safety.
Dr. Walter Willett, professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health, explains: “Appropriate processing can preserve nutritional content or improve accessibility, especially for seasonal produce. It can also enhance food safety, as seen with pasteurized milk. Fermentation can even boost the health benefits of certain foods, like yogurt.”
So, when does food processing become detrimental? Which processed foods should you avoid? Let’s delve into the details.
Defining Processed Foods
Processed foods are those that have undergone changes from their natural state. This can range from simple actions like chopping and freezing vegetables to removing inedible parts like nut shells. This type of modification represents minimal processing.
The next level involves foods with a few added ingredients. Examples include crackers made with wheat, oil, and salt; freshly baked bread; or canned vegetables preserved in water and salt.
“Ultra-processed” foods represent an even greater degree of alteration. Dr. Willett notes, “Ultra-processing often obscures the original food’s identity and introduces additives like preservatives, oils, sugars, salts, colors, and artificial flavors – essentially, junk food.”
Examples of ultra-processed foods include hot dogs, deli meats, cheese puffs, doughnuts, frozen pizza, white bread, cookies, microwaveable dinners, and soda.
Woman examining food label in supermarket to identify processed foods, focusing on ingredients and nutritional information
The Risks of Processed Meats
Processed meats rank among the least healthy food choices. Examples include bacon, sausage, ham, hot dogs, salami, and deli meats. These products are typically high in salt, unhealthy saturated fats, nitrates, nitrites, and other chemical additives (colors, flavorings, and preservatives).
Increased consumption of processed meats has been linked to higher risks of cardiovascular disease and colorectal cancer. A 2019 study in the International Journal of Epidemiology, involving almost 500,000 participants, found that individuals consuming red or processed meat four or more times per week faced a 20% higher risk of developing colorectal cancer over a five-year period, compared to those consuming these meats less than twice a week.
The International Agency for Research on Cancer, a part of the World Health Organization, classifies processed meat as a carcinogen for colorectal cancer in humans.
Health Implications of Ultra-Processed Foods
Health experts primarily caution against ultra-processed foods due to several health risks.
Dr. Willett explains, “Processing often diminishes the nutritional value of foods, such as when refining whole grains. It can also generate harmful molecules like trans fats or introduce excessive amounts of detrimental ingredients like salt and sugar.”
Consuming large quantities of ultra-processed foods is linked to increased risks of chronic inflammation, various chronic diseases (including heart disease, diabetes, inflammatory bowel disease, obesity, and cancer), and premature mortality.
A 2019 BMJ study, following over 105,000 individuals for five years, revealed that each 10% increase in ultra-processed food consumption correlated with a 12% rise in the risk of heart attack or stroke. Another 2019 BMJ study, tracking almost 20,000 people for an average of 10 years, found that participants consuming more than four servings of ultra-processed foods daily had a 62% higher risk of death from any cause during the study period, compared to those consuming two servings per day.
Identifying Ultra-Processed Foods: What to Look For
Generally, ultra-processed foods are easily recognizable by their extensive ingredient lists. They are commonly found on store shelves, in freezers, refrigerated sections, delis, and bakeries. Typical examples include packaged, ready-to-eat entrees or meals, prepared side dishes, snacks, and sweets (like cookies and cakes).
However, some ultra-processed foods may deceptively appear healthy, such as fruit-flavored yogurts, refrigerated soups, refrigerated pastas (like chicken tortellini), granola bars, juices, breakfast cereals, frozen yogurt, low-fat salad dressings, condiments, butter substitutes, low-salt crackers, or nut butters.
How to Know If a Food Is Processed: Reading the Label
The key is to carefully read the ingredient list on the food label. A long list of ingredients, especially those that are chemical-sounding or unfamiliar, indicates that the food is likely ultra-processed. Opt for products with the shortest, most recognizable ingredient lists whenever possible.
Occasional Indulgence: Is It Acceptable?
Avoiding ultra-processed foods entirely can be challenging, particularly when you’re pressed for time or simply want to enjoy a muffin, deli sandwich, or homemade ragù with chicken sausage. Is it permissible to occasionally deviate from strict avoidance if you’re generally healthy?
Dr. Willett suggests, “Almost any indulgence is fine if it’s infrequent, like once a month. However, pay attention to other ingredients. For instance, the ragù could be acceptable if the salt content is below 200 milligrams per serving.”
Further guidelines: Maintain a total daily salt intake below 2,300 mg, unless otherwise advised by your doctor. Limit saturated fat to a maximum of 10% of your daily calorie intake. Keep added sugars under 24 grams per day for women and 36 grams per day for men.
Prioritize whole, unprocessed foods within a plant-based diet (vegetables, legumes, fruits, whole grains, nuts, and seeds) as much as possible.
Importantly, Dr. Willett emphasizes: “Unprocessed doesn’t automatically equate to healthy. A diet consisting primarily of red meat, milk, and potatoes, while unprocessed, is far from ideal.”
