Does Fast Food Put You on the Fast Track to Depression?

What’s your idea of comfort food? Freshly baked homemade cookies? Your mom’s gooey mac and cheese? Or maybe you prefer something a little bit, um, faster? As in, fast food? Do you crave things like hamburgers, fries, and chicken nuggets from a famous franchise when you need a little belly-based comfort? Well, if that’s the case, you might just want to start turning elsewhere for your comfort. In addition to the things we already know that fast food can do to our bodies, it might also have some surprising – and disturbing – effects on our brain and mood. Studies now seem to show that there is a link between anxiety and depression and the fast food that so many of us love.

Why It’s Hard to Quit the Fast Stuff

You might be thinking, “Hey, it just tastes good,” and that’s that. But it might not actually be that simple. There might be more scientific reasons why you’re craving fast food, and why you continue to eat it, even though it’s no secret that it’s bad for you. 

First of all, yes, it does taste good. Otherwise why would an estimated 36.6% of the U.S. population devour drive-through deals on a daily basis? But it tastes good to many of us because food scientists have spent decades adjusting the flavors of ultra-processed foods so that we keep coming back for more. But studies also suggest that:

  • The trans fats in many fried foods might hinder your brain’s ability to discern how much you’ve eaten and how hungry you are.
  • person holding McDonald's fries and eating oneFast food can even trigger the pleasure centers of the brain to release dopamine, the same chemical that fuels addictions, so you might end up needing more and more fast food to feed your cravings. 
  • Brain scans also reveal how sugar can be addictive: the more you eat, the more you’re likely to keep craving it. And what does sugar have to do with fast food? It’s not just that the soda that you drink to wash down your meal is loaded with sugar, it’s also that some of the dishes themselves have much more sugar than you might think. For example, one salad on the menu at a popular fast food chain packs a whopping 40 grams of sugar – and keep in mind that most public health organizations recommend that you consume no more than 24 grams of sugar per day
  • In 2019, a landmark study found that those on an ultra-processed diet consumed 508 more calories on average compared to those who ate whole and plant-based foods, leading experts to speculate whether these foods are somehow addictive. Researchers don’t know exactly why, but processed foods seemed to encourage more snacking. “There may be something about the textural or sensory properties of the food that made the [participants in the study] eat more quickly,” said Kevin Hall, of the National Institute of Diabetes and Digestive and Kidney Diseases. “If you’re eating very quickly, perhaps you’re not giving your gastrointestinal tract enough time to signal to your brain that you’re full. When this happens, you might easily overeat.”

All of that is definitely food for thought. You might think that heading to the drive-through for lunch or dinner is just a quick way to get some comfort food to fill you up, but turns out you’re not doing either: comforting yourself OR filling yourself up. And so you’ll just end up going back for more, and risk not only overeating and expanding your waistline, but also changing your mood for the worse. 

Your Brain on Fast Food

So fast food messes with your brain in that it triggers cravings, but what does fast food, or any ultra-processed type of food, have to do with your mood and mental health? Let’s take a look at a few studies that suggest a disturbing link between them: 

  • Research published in the journal Nutritional Neuroscience found that adults under 30 who ate fast food three times a week scored higher on levels of mental distress. The researchers think this is because fast food is typically high in saturated fats, trans fats, and omega-6 fatty acids. While some of these fats are beneficial and, in fact, necessary for brain function in smaller doses, an excess can trigger an inflammatory response. Past research has linked this inflammation to anxiety and depression.many sugar cubes on a table
  • Remember those crazy sweet salads? A study of around 8,000 adult participants found that men who regularly consumed around 67 grams per sugar per day were 23% more likely to be diagnosed with depression, which could, again, be caused in part by an inflammatory response.
  • A 2019 study of teenagers found that higher urine levels of sodium, and low potassium levels, both of which you’d expect from a diet of highly processed fast food, predicted more signs of depression a year and a half after the study, even after adjusting for variables such as blood pressure, weight, age and sex.
  • A meta-analysis of research from the United States, Spain, France, Australia, Greece and Iran published in the journal Nature also found a “robust association” between diet and depression. Their results showed people who avoided a highly processed diet, and instead followed a Mediterranean diet of things like fresh fruits, vegetables, nuts, seeds and little red meat or processed foods, had reduced risk of depression.
  • A Spanish study published in the Public Health Nutrition journal found that consumers of fast food, compared to those who eat little or none, are 51% more likely to develop depression. Not only that, but they found that “the more fast food you consume, the greater the risk of depression,” according to Almudena Sánchez-Villegas, lead author of the study.
  • Studies have shown that excessive fast food consumption is also linked to anxiety symptoms, probably because the refined carbohydrates in many fast food items can cause your blood sugar to fluctuate. Extremely low blood sugar can cause panic attacks, insomnia, and other anxiety symptoms. Not only that, but the lack of omega-3 fatty acids in fried food can cause your brain to mimic anxiety symptoms.

More worrying food for thought. And while some researchers say they’re not really sure if eating fast food causes depression, or if those who are predisposed to depression are more likely to consume fast food (after all, we do call it comfort food, right?), it seems pretty clear that eating fast food can be a big problem for your body and mind.

Is There an Antidote?

whole cooked fish on a plate with lemons on it and olives next to it
The Mediterranean diet is a great diet to follow because it is full of omega-3 fatty acids and other great vitamins.

We don’t want to sound like your mom, but you know what we’re going to say. The solution is less junk food, and more healthy foods like fresh fruits and veggies. And that’s not just the mom in us talking: it’s science. 

While scientists are still studying the link between diet and depression, studies do suggest that certain nutrients and foods can play a preventative role. B vitamins, omega-3 fatty acids, and folates, as well as the foods that make up healthy diets like the Mediterranean diet, like fish and olive oil, have been linked to a lower risk of developing depression.

And, the same study that found that adults under 30 suffered from mental distress after eating too much fast food had some interesting findings for older adults. It found that eating more fruits and veggies, as well as eating fewer carbohydrates of other types, actually reduced anxiety and depression. That’s because fruits and veggies are bursting with antioxidants, which help protect the brain. 

Our days are filled with decisions we need to make, not least being what we should put into our bodies to fuel them. And that decision might have a little more weight than we sometimes give it: those quick trips to the drive-through could start adding up and wreaking havoc on your body and mind. We’re not saying that you should never indulge in your favorite comfort foods, but you just might want to re-evaluate how comforting your choice of indulgence actually is.