The United States spends more on healthcare than any other wealthy nation, yet its population is sicker and dies younger. In 2021, the U.S. devoted 17.8% of its GDP to healthcare, nearly twice the average among comparable countries. Life expectancy, meanwhile, lagged three years behind the average for high-income nations. That paradox has no single explanation. It’s the result of overlapping forces: what Americans eat, how the healthcare system is structured, widespread economic inequality, and lifestyle patterns that quietly erode health over decades.
Americans Eat Differently Than Other Countries
More than half of all calories consumed in the U.S. come from ultra-processed foods. CDC survey data from 2021 to 2023 puts the figure at 55% for anyone over age one. For children and teenagers, it’s even higher: nearly 62% of their daily calories come from products that are industrially formulated, heavily modified, and designed to be cheap, shelf-stable, and easy to overconsume. These aren’t just snacks. They include packaged breads, flavored yogurts, frozen meals, sweetened drinks, and breakfast cereals that form the backbone of the standard American diet.
This matters because ultra-processed food consumption is directly associated with higher rates of cardiovascular disease and earlier death from all causes. Heart disease is the leading killer in the U.S., responsible for more than 683,000 deaths in 2024 alone. Cancer, the second leading cause, claimed nearly 620,000 lives. Both conditions are strongly influenced by diet. The sheer volume of processed food Americans eat is not matched in most peer countries, and it helps explain why the U.S. has the highest obesity rate among high-income nations, nearly double the average.
Obesity Has Become the Norm
As of the most recent CDC data (2021 to 2023), 40.3% of American adults are obese. That’s not overweight. That’s a BMI of 30 or higher, the threshold where risk for diabetes, heart disease, stroke, and certain cancers rises sharply. Four of the top ten causes of death in the U.S., including heart disease, stroke, diabetes, and kidney disease, are closely linked to excess weight and the metabolic dysfunction it causes.
Obesity at this scale isn’t a matter of individual willpower. It reflects an environment where the most affordable, accessible, and heavily marketed foods are calorie-dense and nutrient-poor. Portions are larger, food deserts are common in lower-income areas, and physical activity is engineered out of daily life in car-dependent communities. The result is a population-wide metabolic crisis that no other wealthy country has matched.
The Healthcare System Treats Sickness, Not Health
The U.S. spends far more per person on healthcare than any comparable country, yet Americans see the doctor less often, averaging just four visits per year, below the norm for high-income nations. That’s a telling detail. The money flows overwhelmingly toward treating disease after it develops, not toward preventing it in the first place.
One structural reason: the U.S. has roughly two specialists for every primary care physician, almost the inverse of most Western countries. Primary care doctors are the ones who catch high blood pressure before it causes a stroke, screen for diabetes, and manage the slow-building conditions that account for the majority of American deaths. Without a regular primary care doctor, outcomes get measurably worse. Research has found that people without a primary care physician are 3.5 times more likely to have severe, uncontrolled hypertension compared to those who do. When the system is tilted toward specialists and acute care, the everyday prevention work that keeps populations healthy falls through the cracks.
Cost is another barrier. Millions of Americans delay or skip care because of what they’ll owe out of pocket, a dynamic that barely exists in countries with universal coverage. By the time many people enter the healthcare system, their conditions are advanced and far more expensive to treat.
Income Inequality Shortens Lives
Health in the U.S. tracks closely with income, and the gaps are stark. Americans living below the federal poverty line can expect to live roughly 6.5 fewer years (from age 25 onward) than those earning four times the poverty level or more. That’s not a subtle difference. It’s the equivalent of skipping an entire decade of middle age for tens of millions of people.
Lower income means worse access to nutritious food, fewer safe places to exercise, more exposure to environmental hazards, less stable housing, and greater difficulty affording medical care. It also means higher levels of chronic stress, which has its own biological toll. When the body stays in a prolonged stress response, it drives up blood sugar, promotes inflammation, and accelerates the same metabolic pathways that lead to diabetes, heart disease, and cognitive decline. The U.S. has wider income inequality than most peer nations, and health outcomes reflect that gap at every level.
Sleep Deprivation Is Widespread
About 30% of American adults, roughly one in three, regularly sleep less than seven hours a night, the minimum the body needs for basic metabolic and immune function. Short sleep is linked to weight gain, insulin resistance, elevated blood pressure, and a weakened immune response. It also impairs judgment and reaction time, contributing to the roughly 197,000 Americans who died from unintentional injuries in 2024, the third leading cause of death.
Long work hours, shift work, screen use, and high stress levels all contribute. In countries with shorter average workweeks and stronger labor protections, sleep duration tends to be higher, and the downstream health consequences are less severe.
These Problems Reinforce Each Other
What makes the U.S. health picture so difficult to untangle is that none of these factors operate in isolation. Poor diet drives obesity. Obesity drives chronic disease. Chronic disease drives healthcare costs. High healthcare costs discourage preventive care. Economic inequality limits access to better food, safer neighborhoods, and adequate sleep. Stress from financial insecurity worsens metabolic health, which increases disease risk, which creates more financial strain.
The ten leading causes of death in the U.S. accounted for nearly 71% of all deaths in 2024. The majority of those causes, including heart disease, cancer, stroke, diabetes, liver disease, and kidney disease, are heavily influenced by the same modifiable factors: diet, physical activity, weight, stress, sleep, and access to consistent medical care. Life expectancy did tick up to 79 years in 2024, partly due to declines in deaths from injuries, heart disease, and cancer. But even with that improvement, Americans still die younger than people in most comparable nations, spending far more for the privilege.