This Is Your Brain on Junk Food

It probably comes as no surprise that diets high in ultra-processed foods or “junk” foods aren’t great for your body. These foods, often filled with a lot of calories, fat, carbs, sugar and sodium but with limited nutritional value, can make it difficult to maintain a healthy weight. They may also raise your risk of health conditions such as high blood pressure, heart disease, type 2 diabetes and some cancers. But ultra-processed foods may affect more than just your body – they may affect your brain, too.

Recent research suggests that ultra-processed foods can act like addictive substances, much in the same way as alcohol, nicotine or drugs such as cocaine. They may also affect how we learn and remember. Additionally, it is believed that eating too much ultra-processed food may affect how we feel and may even raise our risk for mental health problems.

What are ultra-processed foods?

These are foods that typically come in boxes, bags and packages at the grocery store, such as chips, cookies, crackers, ice cream and snack bars. Even foods like breakfast cereal and yogurt are often highly processed. When these foods are made, the cellular structure of ingredients is broken down to make them easier to eat and digest quickly, which also means they hit our brain fast. Ultra-processed ingredients are designed to enhance flavor, texture and cravability and the foods are also usually high in fat and sugar, which causes us to want to keep eating them.

How do ultra-processed foods affect the brain?

It is not yet understood exactly how these foods affect brain activity and more research needs to be done on the subject. What is known is that many ultra-processed foods have a strong effect on the brain’s reward system and do so quickly. This is the part of the brain that is involved in pleasure, motivation and learning.

One study showed that after eating high-fat, high-sugar snacks for a period of eight weeks, participants had higher brain activity when they saw similar food elsewhere. So if you see a commercial or pass a box of your favorite cookies, heightened brain activity may up your cravings and make it more likely you’ll eat the food again. This may be why people feel like they’re addicted to junk food and can’t stop eating it. Or why they feel irritated or agitated when they try to cut back on eating these foods.

Other research has suggested that eating processed foods that are high in saturated fat and added sugar may reduce performance on some learning and memory tests. And according to a review of research in the journal BMJ, ultra-processed food may increase your risk of depression, anxiety and sleep problems.

So what can you do to change how ultra-processed foods affect your brain?

The answer is simple. Eat less of them. Focus your diet primarily on whole foods that come directly from nature, such as fruits, vegetables, whole grains and lean proteins, or minimally processed foods. Read labels and avoid products with ingredients that are unfamiliar or that you can’t pronounce. By reducing your consumption of ultra-processed foods, you’ll likely find that you crave them less. You’ll also be doing something good not only for your body, but for your brain as well.