Drop the junk food and get off the couch.

It's no secret that obesity is a global health issue. According to the World Health Organization, obesity has more than doubled since 1980. In 2014, 39 percent of adults aged 18 years and over were overweight, and 13 percent were obese.

What's the cause of obesity? It's a combination of increased intake of energy-dense foods as well as physical inactivity.

Let's break down these two aspects and see if there's a way to change our delicious and relaxed ways.

Energy-dense foods

They're at the checkout counter at the grocery store. They tempt you when you're paying for your sandwich at Potbelly. Their pictures seduce you on every restaurant menu. They call you by name from the cookie jar at home. And doughnuts ... mmmmm, doughnuts.

Energy-dense foods — also commonly known as junk food — are packed with calories but lacking in nutrients. Junk food is likely processed and packaged, typically with no preparation time. We're talking high levels of sugar, sodium and fat.

According to a recent study, the American diet can be described in one terrifying word: ultraprocessed. These ultraprocessed foods delivered 58 percent of energy and a whopping 90 percent of added sugars Americans consume in a day.

You may recognize these types of food in your daily diet: breads, cakes, salty snacks, french fries, chicken nuggets, potato chips, sodas, cookies, deli meats, fast food, sugary cereal, etc. They make appearances in mine. It's the American way.

When do these junk food habits form? Researcher Victor Fulogoni analyzed data from National Health and Nutrition Examinations Surveys from 2011 to 2012 for 4,406 children under the age of 2. The results show this "American diet" makes its appearance much earlier in life than expected.

"When breastfeeding begins to stop, and they transition to regular foods, that's when we see the American diet creeping in," Fulgoni told The Washington Post.

According to his analysis, by U.S. children's first birthdays, their diets are already totally imbalanced. On most days, just 30 percent of 1-year-olds are eating vegetables. And 40 percent of these children's diets were being filled with things like crackers, cookies and other sweet and salty snacks. And the data proves that once these unhealthy foods are introduced into a child's diet, they stick around for good.

A recent animal study published in Experimental Physiology discovered that a diet consisting of mainly junk food can cause as much damage to the kidney as Type 2 diabetes.

"The Western diet contains more and more processed junk food and fat, and there is a well-established link between excessive consumption of this type of food and recent increases in the prevalence of obesity and Type 2 diabetes," Dr. Havovi Chichger, lead author of the study, explained. "In our study, Type 1 and Type 2 diabetes both induce changes in glucose transport in the kidney, but junk food or a diet high in fat causes changes that are very similar to those found in Type 2 diabetes."

Physical inactivity

Are you a part of the 20 percent? An underwhelming 20 percent of Americans participate in the recommended levels of regular physical activity.

Regular physical activity for adults, as recommended by the Centers for Disease Control and Prevention, consists of 150 minutes of moderate-intensity aerobic activity and muscle-strengthening activities on two or more days a week that work all major muscle groups including: legs, hips, back, abdomen, chest, shoulders and arms.

Did you know it's been proven and time again

that exercise is medicine?

Researchers confirmed in an editorial in Cardiology, that regular physical activity is the "magic bullet" to combat the global epidemic of obesity and heart disease. The authors reveal that physical activity has so many benefits beyond body weight control — including blood pressure, cholesterol, triglycerides, diabetes, heart attacks, strokes, arthritis, mood, energy, sleep and sex life.

If those weren't enough reasons to get you moving, JAMA Internal Medicine published new research on how higher levels of physical activity can prevent development of 13 types of cancers.

Prevention

What are the consequences of being overweight and obese? As mentioned above, the health implications are practically endless.

The answers to prevention are crystal clear: healthier eating and more moving around. But where do you start if you're still snacking on the couch?

The authors of the Cardiology article titled "Regular Physical Activity: A 'Magic Bullet' for the Pandemics of Obesity and Cardiovascular Disease," noted that a daily brisk 20-minute walk can burn around 700 calories a week. This would result in a 30-40 percent reduced risk of coronary heart disease.

According to the 2015-2020 Dietary Guidelines for Americans, healthy eating is one of the most powerful tools we have to reduce the onset of disease. Why not clean up your menu for the sake of a long and healthy life?

If being overweight and at greater risk for disease doesn't fade your love for junk food, maybe a recent study out of George Washington University, published in Environmental Health Perspectives, will.

Researchers found people who had eaten fast food in the past 24 hours had high levels of phthalates in their systems. What's a phthalate and why should you care? It's just a family of chemicals used to make plastics flexible. Just like chewing on a raincoat or your vinyl kitchen floor. Gross.

"Our findings raise concerns because phthalates have been linked to a number of serious health problems in children and adults," says lead author Ami Zota, ScD, MS, an assistant professor of environmental and occupational health at Milken Institute SPH.

The proof is in the pudding. Now is the perfect time to reconsider your diet and exercise habits.