Childhood obesity has been called an epidemic, but in some ways, thats wishful thinking. Because with an epidemic, you can usually pinpoint a cause and potential solutions. Childhood obesity is more like fighting a hundred infections at once and trying every medication youve got, hoping something sticks.

Worldwide, obesity among kids is 10 times higher than it was in 1975, and many experts believe its going to get much worse. The U.S. has some of the highest rates: According to the Centers for Disease Control , 1 in 5 school-aged children and adolescents in the United States are affected by obesity. The issue impacts kids as young as two years old.

Obesity rates among American children continue to rise despite widespread awareness of the associated health dangers such as an increased risk of certain cancers, diabetes and heart disease, and obesitys effects on hormones involved in controlling blood sugar and puberty .

To some degree, there has been modest progress toward healthier eating for kids in the U.S. mainly through efforts to improve school lunches and tax sugary beverages but this country is struggling just as much as everyplace else in the world, says Erica Kenney, a researcher in the department of nutrition at the Harvard T.H. Chan School of Public Health.

Addressing childhood obesity is absolutely like playing whack-a-mole, she said. There are so many pieces to this, so many factors that are cultural, environmental, political and systemic. You target one or two pieces of it and then 10 more take its place. Obviously, everyone wants healthier kids. But no one has yet come up with the best strategy to make that happen.

This issue is due to a mess of factors, from ineffective policymaking to socioeconomic inequality to a pervasive tendency to blame the individual . But small steps of progress both in the U.S. and in other countries setting meaningful new precedents offer some degree of hope that the right combination of strategies can add up to lasting, healthy change.

Why children gain weight beyond levels that are considered healthy and then maintain or increase that weight into their teens and beyond can be attributed to a wide range of confounding variables, Kenney noted. Those include genetics, the ubiquity of fast food, the broadly accepted value of sugar as a reward, parental eating habits, metabolism changes, sleep problems, childhood trauma, race, neighborhood design and safety, mental health concerns, chronic health conditions, economic disparity, school nutrition policies, stigma and bullying, social and cultural cues that determine food choices, and legislation at the federal, state and local levels.

Even malnutrition could be in play. When most people think of that word, severely underweight children come to mind, and thats an accurate image, but its not the only one. The World Health Organization considers obesity a form of malnutrition as well, which can happen when people are consuming calorie-dense foods that have scanty vitamins and minerals.

And those are just the major factors.

Many kids are facing not just one or two of these challenges, but a bunch of them at once. Take a kid of color in an economically disadvantaged neighborhood, for example already at disproportionate risk for eventual obesity, according to recent research . Not only will that child have genetic factors at play if their parents are overweight or obese, but they may not have access to healthy foods , they may be disproportionately targeted by unrelenting junk food marketing , and they may be affected by weak school nutrition efforts and a lack of safe places to play and walk for exercise.

But what if a kid is in a wealthy white suburb, born to parents who dont carry a genetic push toward obesity, and has plenty of access to fruits and vegetables? Since socioeconomic factors play a huge role in childhood obesity, they would have a better chance of avoiding weight gain, but it isnt a given. They could still be subject to stress, emotional issues, high sugar consumption and metabolism changes.

Once being overweight tips into being obese, the issue gets even tougher, because getting obese children back to a healthier body composition is significantly more difficult than trying to prevent weight gain in the first place.

Its like any chronic disease, says Kenney. Prevention is much easier than treatment. In the case of childhood obesity, thats true at the highest possible level. There is a great deal of evidence that once obesity takes hold in the body, its hard to reverse. Once youre a certain size, the body doesnt like to let go of that.

Thats one of the reasons obese children are significantly more likely to become obese adults. Another reason? Just take a look around.

We are living in the most difficult food environment in history when it comes to nutrition, Kenney states, referring to the overwhelming amount of cheap, energy-dense foods available pretty much everywhere. I go to the hardware store to buy a hammer and at checkout, I have 50 different candy options. It is like that everywhere, as we all know, and it never used to be like that. The availability, and the cheapness, of the options is staggering.

Yet, she adds, our culture tends to put emphasis on the individual, shaming them for not having enough willpower. Thats not true, Kenney says, and it makes obesity prevention and treatment even tougher to roll out.

And keep in mind that kids eating habits are strongly influenced by factors outside their control. They dont buy and cook their own food, but rather are expected to eat what theyre given at home, school, social events and are highly susceptible to predatory junk food advertising . Its not likely youre going to see a middle schooler, alone, examining food labels in the supermarket to make sure shes choosing a product without trans fats.