Even if you stick to a healthy, natural diet, chances are you still eat processed foods.

Technically, many of the healthy foods we eat are processed but it's not what you think. For example, if you have a Mason jar full of organic dried beans, you have processed food in your pantry. Frozen vegetables are processed, even if you picked them from your garden, blanched them and put them in the freezer. The moment you blanched them, you processed them. Peanuts-only peanut butter, steel cut oats, and organic extra virgin olive oil are all processed, and most people would consider those foods part of a healthy diet.

When we say we shouldn't eat processed foods, what we really mean is ultra-processed foods. There's a difference between the two, and a new study says Americans are eating way more ultra-processed than we should, leading to excessive (and often unrealized) sugar consumption.

What are ultra-processed foods?

Ultra-processed foods, according to a 2016 study published in the medical journal BMJ Open, are "industrial formulations which, besides salt, sugar, oils and fats, include substances not used in culinary preparations, in particular additives used to imitate sensorial qualities of minimally processed foods and their culinary preparations."

Let's take a practical look at what that means. I keep whole-grain naan flatbread in my freezer because it rounds out quick, healthy meals in which I also use up a variety of leftovers.

If I made homemade naan, I would make it with processed ingredients like flour, yeast, milk, butter and salt. But I buy naan from the grocery store, and while the brand I buy contains mostly the type of ingredients of a homemade version, it also includes the additive dextrose, a type of sugar.

Sugar in processed vs. ultra-processed foods

Researchers found those who eat a diet that's heavy in ultra-processed foods are getting a lot of added preservatives in their diet in addition to an overabundance of sugar. In ultra-processed foods, sugar makes up 21.1 percent of the calories, on average. In processed foods, sugar makes up only 2.4 percent of the calories, on average. Keep in mind that the USDA dietary guidelines say that sugar should make up only 10 percent of your daily calories.

If we ate ultra-processed foods only occasionally, it wouldn't be as big of a problem. However, researchers found that almost 58 percent of the calories Americans consume are from ultra-processed foods.

If you're eating an average American diet, chances are you're eating too many ultra-processed foods and those foods are adding more sugar to your diet than you would expect. You don't expect, for instance, that a frozen lasagna will contain two teaspoons of sugar per serving. Neither would you expect that a snack-pack portion of applesauce contains six teaspoons of sugar when homemade applesauce doesn't need any added sugars to be sweet and delicious.

If you're looking to decrease the sugar in your diet, decreasing the ultra-processed foods you eat, even the ones that you wouldn't normally associate with sugar, can help you achieve your goal.

Health risks

A 2018 study conducted in France showed people who increased their daily intake of ultra-processed food by 10 percent increased their risk of developing overall cancer by 12 percent and breast cancer by 11 percent. While the study didn't identify the exact reason why ultra-processed foods causes a higher risk of cancer, researchers did have several theories.

One theory is that the foods contain high levels of sodium, sugar and fat. Those ingredients have been linked to obesity, which can also lead to a greater risk of cancer. A second theory is that some ultra-processed foods contain certain additives that have carcinogenic properties. For instance, titanium dioxide is used as a whitening agent or in food packaging to improve food's texture. Studies have shown that the additive could cause lesions on the colon or gastrointestinal inflammation.

Also, another theory is high temperatures used to process the food can create newly formed contaminants. Finally, BPA (Bisphenol A) is commonly used in food packaging and can leech into the food.

While further studies are needed to know the exact reasons why ultra-processed foods can lead to a higher risk of cancer, it's safe to say that the consequences of eating them outweigh the benefits.

Editor's Note: This file has been updated since it was originally published in March 2016.

Robin Shreeves ( @rshreeves ) focuses on food from a family perspective from her home base in New Jersey.

What are ultra-processed foods and are you eating too many of them?
There's processed food and then there's ultra-processed food. One of them adds a lot more sugar to our diets than you realize.