Dr. Hayes Columns — The Life Expectancy Gap, Part 2: The Body

In Part 1 of this series, we looked at the table. This part looks at the body, and it starts with one number: average daily steps. American adults take about 4,774 a day. Adults in other wealthy countries, measured on the same scale, take more. But the table alone could not account for the full 3.7-year gap in life expectancy, and neither can movement on its own. The second piece is how much the body moves.

This part looks at two things. One is how much Americans walk compared with other wealthy countries. The other, and the more important one, is how strongly that walking is tied to how long people live. The second question is the heart of this article.

The comparison rests on one source. In 2017, researchers at Stanford University published a study in Nature that measured daily step counts from the smartphone accelerometer data of more than 717,000 people across 111 countries. The same app, the same kind of sensor. This is not a patchwork of different national surveys. It is one ruler held up to everyone, the same approach Part 1 took with NOVA.

I should be honest about something. In the hospital, I do not often ask my patients whether they get enough exercise. The people I admit are usually already older, already carrying extra weight, or already living with addiction. By the time I meet them, the conversation about walking is often too late. So I think about the value of movement not at the bedside, but in the life that comes before it. Before the hospital, while a person is still well, this is where the data on movement matters most.

In recent years, the answer to that question has become much clearer than it used to be. Studies have now tracked the relationship between step counts and the risk of death across hundreds of thousands of people. Those numbers are the center of this article.

Americans Walk About 4,800 Steps a Day

In the Stanford study published in Nature, the average person worldwide took 4,961 steps a day. The United States came in below that, at 4,774 steps, ranking 30th out of the 46 countries with enough users to measure. The common target people talk about is 10,000 steps. The American average is less than half of it.

A short word on what this number is and is not. The study measured people who carried a particular smartphone app, so the sample is not perfect. It leans toward people who own compatible phones and live in cities, and the researchers say so plainly. But the same lean applies to every country in the data, so the comparison between countries still holds.

One more point of honesty belongs here. This dataset does not list separate figures for Korea or France, two countries that appeared in Part 1. So unlike the table in Part 1, this comparison does not include them. The rule is the same one Part 1 used: if there is no figure measured on the same ruler, it does not go in the same table. Some local Korean surveys report higher step counts, but those come from self-selected groups such as health-app users, which makes them a poor stand-in for a national average. They stay out of the comparison.

How Other Wealthy Countries Measure on the Same Scale

Measured on the same ruler, the average daily steps in the United States come to the lowest of these countries. The figure sits below the global average of 4,961 steps. Japan walks about 26% more than the United States, 6,010 against 4,774.

Spain is worth a note, because it also appeared in Part 1 on the table. It comes out clearly ahead of the United States here too, at 5,936 steps. A country can lead on more than one measure at once.

The usual reading of a low number is that people are not trying hard enough. The researchers and the analyses that followed point somewhere else: to how a place is built. Car-dependent design, missing sidewalks, and separated land use all push daily step counts down. The same person walks less in a neighborhood that is hard to walk in. The number is shaped by the environment as much as by the will of the individual.

What Sweden Shows: The Gap Matters More Than the Average

Sweden is not in the table above, and there is a reason to leave it out of the ranking while still talking about it. The most important finding of the Stanford study was not the average step count at all. It was something the researchers called activity inequality, the gap within a single country between the people who move the most and the people who move the least.

The researchers found that this gap was a stronger predictor of a country’s obesity rate than the average step count was. In other words, a nation’s health depends on how much people walk on average and also on how evenly that walking is spread across the population.

Sweden had one of the smallest gaps of this kind, along with one of the lower obesity rates. The distance between its most active and least active people was narrow. The United States was the opposite. It ranked fourth from the bottom in activity inequality and carried a high obesity rate. So the American picture has two problems layered together: a low average, and activity that is concentrated rather than shared.

The study also noted that where this gap is wide, women’s activity tends to fall further than men’s, so the weight of the gap lands harder on women. The takeaway is that raising the average is not the whole answer. The real question is who is not moving, and which neighborhoods make movement hard.

What 7,000 Steps Changes

This is the part that matters most. The question is how many steps Americans take, and what those steps are worth.

A large dose-response meta-analysis published in The Lancet Public Health in 2025 pooled studies from 35 cohorts across more than ten countries. Compared with 2,000 steps a day, 7,000 steps a day was associated with a 47% lower risk of death from any cause. It was also associated with a 25% lower risk of developing cardiovascular disease, a 47% lower risk of dying from it, a 37% lower risk of cancer death, a 14% lower risk of type 2 diabetes, a 38% lower risk of dementia, a 22% lower rate of depressive symptoms, and a 28% lower risk of falls.

An earlier meta-analysis of 15 international cohorts, also in The Lancet Public Health, pointed the same way. The more steps per day, the lower the risk of death, with the lowest risk reached at roughly 7,000 to 9,000 steps a day.

One correction is worth making. The familiar 10,000-step target was never strongly grounded in evidence. The research suggests 7,000 steps captures most of the benefit and is a more realistic mark for most people. Going beyond it adds little.

This calls for the same care Part 1 asked for. These studies do not say that walking less kills people. They show that death and disease appear more often in groups that walk less. That distinction matters. Still, the signal is strong, drawn from hundreds of thousands of people across many countries, and it follows a clear dose-response shape.

Where the Two Numbers Meet

Now lay the two findings side by side. The average daily steps in the United States come to about 4,774. The point where the risk of death starts to fall meaningfully is around 7,000 steps. The average American day sits well below that line.

That reframes the problem. The issue is not that Americans never exercise. It is that the ordinary American day lands beneath the level of movement where the health benefit begins. Among wealthy countries, the United States is among the furthest from that line.

And this gap is not closed in a gym. It is closed in ordinary life, in whether a neighborhood is built to be walked. That is what shapes an average.

Where the Body Stops Explaining

The data here makes one piece clear. Movement is a strong part of the life expectancy gap, and the United States moves less than its peers while its life expectancy runs shorter.

But the body, like the table, does not account for all 3.7 years on its own. Countries that walk at similar levels still differ in how long their people live. If movement were the whole story, the order of these countries by life expectancy would line up exactly with the order of their step counts. It does not.

So there is more left to explain. Part 1 looked at the daily table and ultra-processed food. Part 3, The Test, turns to who finds a disease earlier when it strikes, which means looking at screening systems. The body is the second piece, not the last.

Plain-Language Reference

If you want to ask “where am I” before reading the next part, a few of the tools on this site line up with what this article covered.

· Fitness Age Calculator (estimate the activity age of your body right now, the direct subject of this article)
· Sleep Age Calculator (sleep feeds directly into recovery and the next day’s activity)
· Burnout Score (chronic fatigue is often the first thing that stops a person from moving)

The Bottom Line

Measured on the same ruler, the average daily steps in the United States come to about 4,774, against 6,010 in Japan, 5,936 in Spain, and 5,444 in the United Kingdom. It walks the least of the group.

And 7,000 steps a day is associated with a 47% lower risk of death from any cause. The American average sits below that line. In study after study, the groups that move the least show the highest risk.

This data does not tell anyone what to do. It only shows that daily movement is not a single workout. It is a choice that accumulates over a long stretch of time. What to do with that choice is yours to decide.

This article is for general educational purposes and does not constitute medical advice. Country step figures come from a single 2017 smartphone dataset and carry the sampling limits described above, so they should be read as broad comparisons rather than exact rankings. Talk with your own physician before making changes to your activity, especially if you have a heart or joint condition.

Take care of yourself. Nobody else will do it for you.