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One Major Side Effect of Eating Fast Food, Says Science

No one is arguing that fast food is healthy, but you may not believe that the overly-processed food could do this much damage.

Fast food is a triple threat when it comes to, well, threatening your health. These "foods" are high in calories, high in glycemic loads (refined carbs that can spike your blood sugar), and are often offered in excessive portion sizes. But wait, there's more! Fast food also typically features processed meat, is generally high in sodium, contains high levels of fat, is lacking fiber, and is missing many essential micronutrients. Phew—did we get everything?

All those troubling features come with countless negative side effects, but there's one big one that is likely at the root of many of these issues: one major side effect of eating fast food is that it's accompanied by eating fewer healthy foods. In other words, as you eat more fast food, you not only suffer from the direct health consequences of eating unhealthy food, but consuming more fast food can also shift you towards eating a less healthful diet even outside of ordering off the Dollar Menu.

Essentially, as you eat more unhealthy foods, those unhealthy foods start to crowd out the remaining healthy foods that were still a part of your diet.

Specifically, studies show that those who eat the most fast food are also more likely to eat less fruits, vegetables, and whole grains, according to a 2013 study published in Nutrition Reviews.

A Public Health Nutrition study also linked greater fast-food consumption to a lower healthy eating index score, and lower intake of vegetables, whole grains, fiber, magnesium, and potassium. In addition, an increase in fast-food consumption over time was associated with a decrease in vegetable intake.

It's this poor diet quality that leads to several of the negative side effects of eating fast food. (See: Dangerous Side Effects of Eating Fast Food Every Day, According to Science.)

For example, numerous studies show that fast food consumption is linked to an increased risk of being overweight and obese. One long-term study—dubbed the CARDIA study—followed over 3,000 people over the course of 15 years. Researchers found that participants who ate at fast-food restaurants at least twice a week gained an extra 10 pounds and had a two-fold greater increase in insulin resistance compared to those who consumed less than one fast food meal a week.

Weight gain isn't the only thing you have to worry about with your fast food consumption. A recent Circulation study found that eating fast food more than twice a week increases your risk of developing type 2 diabetes and dying of coronary heart disease compared to those who eat little or no fast food. All-in, eating a diet rich in fast food has been linked to an increased risk of cardiovascular disease, insulin resistance, type 2 diabetes, belly fat, inflammation, metabolic syndrome, and obesity, according to a 2015 study.

Protect your health and cut back on fast food whenever you can. Trust us, your body will thank you: 7 Amazing Things That Happen When You Give Up Fast Food.

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Olivia Tarantino
Olivia Tarantino is the Managing Editor of Eat This, Not That!, specializing in nutrition, health, and food product coverage. Read more about Olivia
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