Last week, researchers at the the University of Washington released a new study predicting that US life expectancy would fall further and further behind other countries over the next twenty years. Life expectancy will continue to increase, but at a slower rate than many other countries.

Whether or not these predictions ever come true, depend on many of the study’s assumptions also coming true.

Nevertheless, it’s not hard to see why the general health of Americans isn’t exactly headed toward a renaissance.

While recent news stories have pointed toward drug overdoses and suicides as a driver behind rising mortality in the US, the health of Americans continues to be imperiled primarily by obesity and its resulting diseases :

Obesity is a grave public health threat, more serious even than the opioid epidemic. It is linked to chronic diseases including type 2 diabetes, hyperlipidemia, high blood pressure, cardiovascular disease, and cancer. Obesity accounts for 18 percent of deaths among Americans ages 40 to 85, according to a 2013 study challenging the prevailing wisdom among scientists, which had placed the rate at around 5 percent. This means obesity is comparable to cigarette smoking as a public health hazard; smoking kills one of five Americans and is the leading preventable cause of death in the United States… Obese people are between 1.5 to 2.5 times more likely to die of heart disease than people with normal body mass indices (BMIs).

Yet, when we hear about these trends, advocates for socialized medicine are often quick to claim that life expectancy would surely be higher if only the United States had a government health-care system instead of the quasi-market system it has now.

Ignoring the fact that the US already spends more government money on health care than nearly every other country, there’s really no reason at all to assume that, in light of the obesity reality in the US, a European-style healthcare system would lead to a European-style life expectancy.

After all, according to the OECD, the US has an obesity rate of a whopping 40 percent, followed by Chile and Mexico with rates of 34 percent and 33 percent, respectively.

Canada’s obesity rate, meanwhile, is 28 percent, and it’s 26 percent in the United Kingdom. It’s a mere 23 percent in Germany, and 17 percent in France.

The gaps in life expectancy aren’t nearly as large as this. Thus, if anything, we might conclude that the US’s healthcare workers are doing an unexpectedly good job given how committed Americans are to consuming immense numbers of calories, while exercising little.

Given that the US obesity rate is 69 percent higher than that in Germany, one might conclude it’s quite surprising that the German life expectancy is only 2.1 percent higher than the US life expectancy.

[RELATED: “Life Expectancy: If Denmark Were a US State, It Would Rank Equal To or Worse Than Sixteen US States” by Ryan McMaken]

Indeed, instead of assuming that adopting a more bureaucratized health care system would extend life expectancy, we might best look at the burdens that added obesity puts on the health care system, including efforts at prevention.

As the Commonwealth Fund — hardly a libertarian organization — points out, “The medical costs of prevention, diagnosis, and treatment are estimated at $147 billion in 2008 dollars,” and “Providing affordable health care to Americans will prove increasingly difficult as weight gain continues to ravage the United States.”

In other words, American obesity means Americans are starting out less healthy before they even engage the healthcare system — and are requiring that vital healthcare resources be redirected toward prevention and treatment of diseases related to obesity.

The end result is more expensive healthcare, more disease, and ultimately, more death.

Often advocates for more government solutions will then claim that some more government money for nutrition programs, or regulations for food labeling will solve the problem. Except, there’s little evidence that dieting programs or food labeling mandates work. So, simply having more contact with a physician who’s going to tell you to cut out the snacking isn’t going to make any meaningful difference.

What is needed are sizable changes to everyday food culture, and to the nature of daily physical activity.

Neither of these things would be significantly changed by simply spending an extra few billion on medicare.

As far as daily activity goes, the ease and affordability of private transportation looks to be a significant factor.

And when it comes to diet, it’s long been recognized that the American diet is especially unhealthy given the prominence of processed food and fast food. Over time, fast food portions have become much larger, which means these foods have been gradually replacing unprocessed foods.

Not surprisingly, combined with a lack of physical activity, the end result has been obesity, diabetes, and heart disease.

Poverty Doesn’t Cause Obesity

Still looking for a government “solution,” many advocates for more government intervention in the American diet have attempted to claim that “inequality” or poverty causes obesity. They point to a correlation between low income and high obesity rates.

They further point to the alleged existence of “food deserts” in which low-income people supposedly can’t access food other than fast food or convenience-store food.

The problem with this theory is that the evidence doesn’t support it.

In the waning days of the Obama administration, the USDA concluded “improving access to healthful foods by itself will likely not have a major impact on consumer diets or generate major reductions in diet-related disease.” The USDA was specifically referring to a study in which residents of neighborhoods with a new grocery store and increased access to food did not act to improve their diets. “Consumption of fruits and vegetables did not improve,” the study found.

In fact, its unlikely that “food deserts” exist :

Three more-recent studies, by the United States Department of Agriculture, researchers at the RAND Corporation, and myself (publishing in Social Science and Medicine), have all found that low-income neighborhoods have at least as many and often more grocery stores and supermarkets than do wealthier communities.

Nor do all low-income groups surrender themselves to American dietary habits.

For example, researchers have long known that immigrants tend to be healthier than the US population overall. States with larger foreign-born populations tend to have longer life expectancy, and as immigrants become more “Americanized” they become less healthy:

“There’s something about life in the United States that is not conducive to good health across generations,” said Robert A. Hummer, a social demographer at the University of Texas at Austin.

For Hispanics, now the nation’s largest immigrant group, the foreign-born live about three years longer than their American-born counterparts, several studies have found.

Why does life in the United States — despite its sophisticated health care system and high per capita wages — lead to worse health? New research is showing that the immigrant advantage wears off with the adoption of American behaviors — smoking, drinking, high-calorie diets and sedentary lifestyles.

Keep in mind that immigrant groups also tend to have lower incomes and less access to health care services than the general population. And yet their health outcomes tend to be better.

But, continued exposure to American dietary habits can overwhelm the better habits of immigrant groups over time. Japanese-Americans, for example, have far less heart disease than the native white population in the first two generations after emigration. On the other hand, one study shows “cardiovascular risk factors in the third generation Japanese American immigrants are becoming more similar to those in whites.”

So, as the immigrant experience has shown, health is not simply a function of income or accessibility to certain foods and to health services.

And even the left-wing Guardian in the UK appreciates the centrality of diet in life expectancy. Last week, in response to new research claims that Spain will soon move to the top of global life expectancy, the Guardian looked to the role of the Spanish diet:

For Consuelo Borrás, a lecturer in physiology at the University of Valencia, lifestyle remains the most important factor in life expectancy.

Even if the modern world has begun to take its toll on the Mediterranean diet, “it’s still fairly well lodged in the Spanish mentality and we know it’s something that’s important”.

And yet, perhaps not surprisingly, the article repeated the myths around food deserts and American accessibility to health food:

“Fruit and vegetables are affordable for everyone,” he said. “It’s not like in the US, where you have these so-called ‘food deserts’ where you have to drive for miles before you can find a fruit and vegetable store — and, when you do, it’s ridiculously expensive.”

These words were spoken by a researcher at the University of Barcelona, although his assertions appear to be based on conjecture. Not only are there no food deserts, but two recent studies have found that fruits and vegetables are no more expensive than other foods:

The researchers found that the average cost per serving size of the fruit or vegetable snack was $0.34, while the unhealthy snacks was $0.67. The average price per serving of vegetable side dishes was $0.27, compared to the unhealthy side dishes at $0.31. The findings are consistent with a 2012 study from the United States Department of Agriculture (USDA) that found healthy foods were less expensive than unhealthy foods on the basis of edible weight or average portion.

It’s tempting to think that some change in law, or some government program can easily offer the solution to issues with American health. Some look at life expectancy in other parts of the world and conclude that supposed difference in public policy must explain away differences in life expectancy as well. This ignores the reality of deep-seated differences between native-born Americans and the rest of the world in terms of lifestyle, diet, and other behavior affecting health. The idea that a few more government regulations will solve these problems is fanciful at best.