(Ricky Carioti/The Washington Post)

I was chatting with a father on the sidelines of a game the other day. He told me he doesn’t believe that food impacts health because he grew up eating bologna sandwiches and Fritos on white bread with a Twinkie for dessert. He’s healthy after a childhood of junk food, he said, so his kids will be, too.

This is not the first time I have heard this argument.

Yes, it is true that perhaps this particular parent is healthy. Yet, as a generation, we are not.

Over the past 50 years, many medical advances have made it easier for people to survive heart attacks, treat high blood pressure and manage elevated cholesterol. We have surgeries, medicines and treatments that once weren’t available. Sounds good, doesn’t it? So why do Americans have a shorter life expectancy than people in most high-income countries?

If you don’t believe that our generation is getting sicker instead of healthier, check out what the Centers for Disease Control and Prevention and the World Health Organization have to say:

· About half of American adults have at least one chronic condition. One in four adults has two or more. Yet chronic diseases are among the most preventable of all health problems. Chronic conditions include heart disease, stroke, cancer, diabetes, obesity and arthritis.

· Diabetes affects 1 in 5 adults and is the most common cause of disability in America. Fifteen years ago, Type 2 diabetes, once known as adult-onset diabetes, accounted for less than 3 percent of all new cases of childhood diabetes, yet today it accounts for up to 45 percent.

· The rates of obesity for U.S. adults and children have more than doubled since the 1960s.  Most of the increase in obesity in adults has occurred since the 1980s.

· National Health Interview Survey data from 2010 to 2012 estimated 52.5 million adults had arthritis, for which obesity is a known risk factor. And that number is expected to grow.

In 2013, the Institute of Medicine and the National Research Council brought an alarming report to the Senate floor. It noted that although U.S. life expectancy and survival rates have improved over the past century, “Americans live shorter lives and experience more injuries and illnesses than people in other high-income countries.” And over the past three decades, this difference in life expectancy has been growing.

You might be thinking, “This is someone else’s problem” — someone who is fatter than you, spends more time at the doctor than you, or someone with fewer resources than you. But unfortunately, this is everyone’s problem.

“The American health-wealth paradox is a pervasive disadvantage that affects everyone, and it has not been improving,” the report’s authors write. The study, “U.S. Health in International Perspective: Shorter Lives, Poorer Health,” found that the health gap is more pronounced among socioeconomically disadvantaged groups, but white, insured, college-educated and upper-income Americans were still in worse health than similar groups in peer countries.

Why is this happening? The answer is not as simple as Twinkies. Of course what we eat is a contributor, but there are many other possible factors.

· Our generation of adults is the first to be raised with technology including video games, TVs and computers, which leads to a much more sedentary life.

· People spend less time outside. They drive more. A playground or park was once a typical meeting place; now it is the Starbucks, where many sugar-laden foods are sold and people sit to connect.

· This generation of adults is the first to be raised with fast food on every corner. Fast-food sales increased from $6 billion in 1970 to $110 billion in 2000, Eric Schlosser writes in his book “Fast Food Nation.”

· Foods in BPA-lined cans and chemical-filled frozen dinners became easily accessible.

· Per-person consumption of synthetic food dyes has increased fivefold since 1955.

The bad news for our kids is that all the factors above still apply, plus more chemicals in our air, more pesticides in our crops and more antibiotics in our meat.

So parents, let’s face the facts. Yes, we may have eaten loads of processed food growing up. But we know more than our parents did. Our planet is probably more toxic. Our kids are more sedentary. And there is proof that as a generation we are not as healthy as we may think.

So even if your children do not have diabetes, severe food allergies or another obvious sign of being affected by their food and environment, do we really want them to be part of the potentially sickest generation? Our children can’t protect themselves from the environment in which they live or the foods they are fed. We can. And because we all love our children, this is not someone else’s problem to solve; it unmistakably is ours.

Seidenberg is co-founder of Nourish Schools, a D.C.-based nutrition education company.