Are All Processed Foods Unhealthy?

Ask Keri: Should I avoid all processed foods?

Keri Says: The fewer foods you eat that have a food label, the better. A garden doesn’t grow nutrition labels, and the bulk of your food should come without a wrapper, box, or can around it.

However, processing isn’t inherently bad (hello, fermented foods and sourdough bread). There are plenty of minimally processed foods that can play a role in a healthy diet.

It’s important to understand why processed foods tend towards unhealthy, so that you can distinguish between the junk and the packaged-but-still-good stuff (like a jar with nothing but tomatoes, a little olive oil, and spices).

RECIPE: Super Simple Farmers’ Market Marinara

The Overall Issues With Processed Foods

First, knowing the calories, fat, carbohydrate, and protein content of foods is important, but you also want to know what types of foods these nutrients are coming from.

Processing can change the structure of nutrients, therefore altering how your body processes and responds to them. Think about corn, for example. Corn contains a lot of carbs, but it’s a healthy vegetable with a low glycemic index. Eat the kernels whole, and your body slowly breaks down the carbs thanks to fiber, while also absorbing a variety of important vitamins and minerals. But process that corn down into pure starch (all carbs), break down that starch into a syrup, add enzymes, and soon you’ve got a super sweet ingredient known as high-fructose corn syrup. It’s still made from corn, but your body is going to process that version as pure sugar.

Another common example is a protein-rich soybean vs. soy protein isolate. The soy protein isolate in foods like the Impossible Burger does provide protein, but it’s stripped of the other nutrients found in a soybean and makes lots of people’s stomachs hurt because the body digests it differently.

The other big issue is that when foods are processed and packaged, companies tend to add other “stuff” to make them taste better and last longer. I’m talking about tons of added sugar, salt, artificial sweeteners, colors, and preservatives. I want to minimize all of that in a healthy diet.

New Research on Processed Foods

That’s my thinking from a nutrition perspective, and recently, new research has been coming out that further supports the advice I’ve been giving for a very long time.

Two large epidemiological studies published in BMJ found more processed foods in individuals’ diets was associated with significant increases in risk for both cardiovascular disease and all-cause mortality (AKA people who reported they ate more processed foods died sooner).

Meanwhile, a small but significant clinical trial conducted at the National Institutes of Health (NIH) found participants on a processed food diet for two weeks consumed more calories and gained more weight than those on an unprocessed food diet. (Meals were designed to be matched for calories, macronutrients, sugar, sodium, and fiber, whether processed or unprocessed.)

A study from the University of Michigan and Virginia Tech reports that highly-processed foods can be addictive based on the criteria set for tobacco addiction. Authors of the US study, write that the ability of highly processed foods (HPFs) “to rapidly deliver high doses of refined carbohydrates and/or fat appear key to their addictive potential. Thus, we conclude that HPFs can be considered addictive substances based on scientifically established criteria.”

The Bottom Line on Processed Foods

Eating a bag of potato chips every once in a while isn’t going to kill you, but my advice is to limit processed foods in your diet as much as possible to reduce excess intake of sugar, sodium, and other unhealthy chemicals, to take care of your heart, and to live a long, active life. When you do buy processed foods, look for those with whole food ingredients and without lots of sweet (and extra) stuff added.

(Photos: Shutterstock)