The video this page belongs to walks a modern inspector through a 1974 house with a clipboard. Asbestos in the sprayed ceiling. Plate glass in the door to the garden. Formaldehyde in the panelling and the cabinet boxes. An open gas flame in the hall with nowhere to vent. No earth at the bathtub. A six-inch gap on the stairs. Lead in the paint, lead in the solder, aluminium at every connection, and nothing at all mounted on the hall ceiling. Ten things, every one of them legal at the time, every one of them standard, and not one of the rules that followed ever required anybody to take them out. Nearly half of American houses were built before 1980, so most of this is still sitting where it was put.

That is the video. This is the part that did not fit in it, and it starts by taking the title apart.

Here is the document that did not make the script. The InterNACHI Standards of Practice, section 2.2, sets out what a home inspector is not required to do. He is not required to determine “the existence of environmental hazards, including lead paint, asbestos or toxic drywall”. Not the air quality. Not the presence of mould. Not “compliance with codes or regulations”. (InterNACHI Standards of Practice.) The American Society of Home Inspectors carries the same exclusions in its own section 13.

So four of my ten items cannot fail an inspection, because the inspector is not asked to look for them. And the deeper problem is the verb. A home inspection has no pass and no fail. It is a written opinion on a day, and the buyer does what he likes with it. I put a word in the title that does not exist in the trade, because it made the sentence land.

This page is everything I found while building that video, including the places where what I found argued with me. The sources are grouped under the claim each one belongs to, and the section at the bottom is the one to read if you read only one.

To watch the video, go here.

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What the inspector would actually write down

Five of the ten would appear in a real report, and all five as recommendations rather than faults. The annealed patio door, because he can often see the absence of a stamp in the corner of the glass. The bathroom outlet with no ground fault protection, which he is required to test. The stair guard with a six-inch gap. Aluminium branch wiring, visible at the panel. And the missing smoke alarm, which is the one item on the list that most states now attach to the sale itself.

The other five are the business of a laboratory. Asbestos needs a sample sent away. Lead paint needs an X-ray fluorescence gun or a chip test. Formaldehyde needs air sampling. Lead solder needs a water draw. None of it is in the price of an inspection, and none of it is what the man with the clipboard is there to find.

That distinction matters more than it sounds, because it is the whole difference between a house that is dangerous and a house that is old. The five an inspector flags are the five you can see. The five that frighten people are the five nobody looks at.

The ceiling, and how dangerous it was while it stayed up

This is the one I put first, and on the evidence it should not have been anywhere near the top.

In 1991 the Health Effects Institute assembled the largest review ever done of asbestos in buildings and put numbers on the risk of simply living under it. For a person exposed for twenty years from birth, at the levels actually measured in buildings containing asbestos, the estimated lifetime risk was about 3 cases of mesothelioma and 1.3 cases of lung cancer per million people. Start the same exposure at fifty and the mesothelioma figure falls to 0.02 per million. Measured fibre levels in those buildings averaged around 0.0002 fibres per millilitre, which the report describes as roughly 50,000 times below the industrial exposures that killed the men who fitted the stuff. (Asbestos in Public and Commercial Buildings, chapter 6.)

Three per million is not zero, and the review was contested at the time by people who thought its methods too generous. But it is the number, and it explains why the EPA has never told anyone to take a popcorn ceiling down. The danger in that ceiling is entirely a danger of disturbance. It arrives with a scraper, a drill, a man putting in recessed lighting on a Saturday.

I knew that and said it in the video. I still opened the list with it, because a ceiling full of asbestos is the most frightening sentence available, and the ordering of a list is an argument whether you intend it or not.

The paint, and the thing that actually cleaned the blood

The strongest figure in the video is the blood lead collapse. Mean blood lead in American children aged one to five was 15.2 micrograms per decilitre in 1976 to 1980 and 0.83 today. (CDC, Blood Lead Levels in U.S. Children Ages 1 to 11 Years, 1976 to 2016.)

I put that figure directly after the 1978 paint ban, which invites you to join the two. Look at when the fall happened. By 1988 to 1991 the figure was already down to 3.6. That is four fifths of the entire drop, finished inside a decade, in houses where not one wall had been stripped. The ban of February 1978 governed the sale of paint. It required no one to remove a single square foot of what was already on the skirting board, and most of it is still there.

What moved the needle was the fuel. Pirkle and colleagues, analysing the same surveys, found blood lead across the whole population aged 1 to 74 fell 78% between 1976 and 1991, and wrote that “the major cause of the observed decline in blood lead levels is most likely the removal of 99.8% of lead from gasoline and the removal of lead from soldered cans”. Lead used in petrol went from 186.47 million kilograms in 1976 to 0.47 million in 1990. (Pirkle et al, The Decline in Blood Lead Levels in the United States.)

So the child in that house did get better, dramatically, and it was mostly because of what stopped coming out of the car outside and what stopped being soldered into the tin of peaches. The paint stayed. I gave the credit to the wrong rule.

The heater, and the seventy

The unvented gas heater beat is accurate in its shape and loose in its dating. The figure of about seventy carbon monoxide deaths a year comes from the Commission’s 1980 announcement of the oxygen-sensor standard, not from the 1978 proposal to ban. The 1978 release put it at at least sixty deaths since 1973. (CPSC 1978, CPSC 1980, CPSC 1984 revocation.) The narration attributes both to 1978.

Set the two figures the Commission gave against each other and you get the reason the ban died. Seventy deaths a year, spread across seven to ten million heaters, is roughly one death a year for every hundred and twenty thousand heaters in use. Every one of those deaths is a family, and no household could be persuaded that the thing warming the hall was the thing. That is how a hazard concentrated in poor and rural houses survives three separate attempts to regulate it and is on sale this afternoon.

The smoke alarm, and the reversal at the end

The closer is where the script is least accurate, which is awkward, because it is also the part I am proudest of.

Four figures need correcting. The narration says 99% of homes report a smoke alarm; the National Fire Protection Association puts it at 96 to 97%. It says the fire death rate fell to 10.5 per million by 2017; the United States Fire Administration says 11.2. (USFA, Fire in the United States.) It says deaths per thousand reported home fires were 8.9 in 2024; the verifiable NFPA figure is 7.4 in 2017 against 7.1 in 1980. The direction holds and the number does not.

And the escape times. The pairing of seventeen minutes against under three comes from a UL press campaign, not from the research. The test data, which is what I should have quoted, are from Steve Kerber’s work at the UL Fire Safety Research Institute: legacy furnished rooms took more than twenty-nine minutes to reach flashover, modern ones between 3 minutes 20 and 4 minutes 45. (Analysis of Changing Residential Fire Dynamics.) Credit UL FSRI when you repeat this, because almost nobody does.

One more thing complicates the reversal, and I left it out. The alarm on the ceiling is a self-reported alarm. NFPA’s own summary of the field data is that a working smoke alarm cuts the risk of dying in a home fire roughly in half. (NFPA, Smoke Alarms.) The gap between a house that reports an alarm and a house where one sounds is where most of the remaining deaths sit, and it is a gap about batteries rather than about building codes.

The two smaller numbers

Consumer-product electrocutions in the mid-1970s: the narration says about five hundred a year, the Commission says about six hundred, falling to roughly a hundred by 2018 to 2020. (CPSC.) The fall is bigger than I said.

Sixty-three million homes built before 1980: I could not verify that against a Census table I can hand you. What is supported is the share. Nearly half of owner-occupied American homes were built before 1980. (NAHB, analysis of the 2023 American Community Survey.)

What did not survive

Nothing fails a home inspection, because there is no fail. The title promises a verdict the trade does not issue, on four items the inspector is told he need not look for. (InterNACHI SOP 2.2.) If I rebuilt the video, the spine would be ten things that were legal, standard, and are still sitting there, which is the ending I already wrote and a better title than the one I chose.

The lead in those children was mostly not from the paint. Four fifths of the fall in children’s blood lead was over by 1991, and the researchers who measured it put it down to petrol and tin cans. (Pirkle et al.) The 1978 ban removed nothing from anybody’s wall. It is still the right rule, and it is not the rule that did the work.

The ceiling was close to harmless while nobody touched it. Around 3 mesothelioma cases per million for twenty years of exposure from birth. (Health Effects Institute, 1991.) The item that leads my list is the item with the smallest number attached to it, and I ordered the list by dread.

The dangerous house is the one you are standing in. The rate of preventable injury deaths in and around American homes was 8.6 per 100,000 in 1990 and 31.7 in 2024, a figure that has risen 190% since 1999. Of the 90,800 deaths in 2024, poisonings account for 58,300 and falls for 32,500. (National Safety Council, Deaths in the Home.) Almost none of it is the building. The 1970s house was full of materials that might hurt you slowly. The 2020s house contains a medicine cabinet and a staircase and an ageing population, and it kills nearly four times as many people per head as the house I spent nine minutes frightening you about.

Half the list was going out of fashion before any rule arrived. Lead paint was being phased out commercially through the fifties and sixties, which is why only about 24% of homes built between 1960 and 1978 contain it against 87% of homes built before 1940. (EPA.) Aluminium branch wiring went into about two million homes between 1965 and 1973 and then the practice stopped, and no federal rule stopped it. (CPSC.) The story I told is of regulators arriving too late. Some of the time the regulators arrived after the industry had already moved, and wrote down what had happened.

And the biggest hazard in that house is not on the list at all. It was the cigarette, and the car in the drive, and the pool with no fence, and nobody wearing a seatbelt on the way to school. I built a list of materials because materials make good television. The things that actually killed children in 1975 were behaviours, and every one of them changed.

The video this comes from: 10 DANGEROUS Things in Every 1970s Home. All Would Fail Today.

A page like this goes up within minutes of each new video. Free, and it stays free.

A boy comes out of a house in the summer of 1976 and does not go back in until he is called. He drinks from the garden hose, thumb over the nozzle, water warm from an hour in the grass. Somebody’s mother hands out biscuits on the step and one goes on the ground, and he picks it up, blows on it, eats it. A single bottle of Coke goes round four children and comes back with a quarter left in it. The dog licks his face and later licks the plate. He makes a mud pie and tastes it, because that is what a mud pie is for. He comes in at six, runs his hands under the tap for about a second, and sits down to eat.

Nobody in that story did anything unusual. That was a Tuesday.

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What was going into him

We know what was going into that boy, which is the strange part, because at that exact moment the government was finding out.

Between 1976 and 1980 a national survey drew blood from American children, and among those aged 1 to 5, 88.2% came back at or above 10 micrograms of lead per decilitre. The average for that age group was 15.2. By 2011 to 2016 the same measurement gave 0.83, and the level at which an American child’s blood lead is now considered worth a phone call is 3.5. (EPA Report on the Environment; Environmental Health Perspectives, 2021; CDC reference value, 2021.)

Nine children in ten were carrying a burden that would empty a school today. And the road it took into them was that Tuesday: hands, dust, soil, mouth. The Environmental Protection Agency puts a young child’s intake at roughly 100 milligrams of soil and household dust a day, and rates its own confidence in the figure as low, because measuring it means chasing tracer elements through a toddler. (Exposure Factors Handbook, chapter 5.)

So that is the thing worth sitting with. The afternoon is now sold back to us as a prescription, dirt as medicine, the dog as an immune booster, and I have made that argument myself. But the medicine and the poison came down the same pipe, through the same hands, in the same mouthful. Only one of them was being measured at the time.

The part that holds up

Children who grow up on working farms, with animals moving in and out of the house, have strikingly less asthma and allergy than children who do not. That result is real, it has been found repeatedly, and the best study of it put early farm animal exposure at an odds ratio of 0.47 for asthma at age 7, which is a halving. (Fall and colleagues, JAMA Pediatrics, 2015.)

That is the strong end of this literature, and it is strong. Hold on to it, because almost everything else is softer than it sounds.

The part that does not

The family dog is not the farm. The same Swedish study followed 276,298 school-age children and found that a dog in the house during the first year of life gave an odds ratio of 0.92, about 8%, not the third that gets quoted. Among preschool children it also found dogs came with a slightly raised risk of pneumonia, 1.13. (the findings, summarised.) And families who already have asthma in them are less likely to get a dog at all, which bends every study of this kind before it starts.

The hose is worse than nostalgia allows. When somebody bought 32 garden hoses and tested them, 7 had at least 100 parts per million of lead in the plastic, 2 of those above 50,000. Water left standing in them came back at 13, 19 and 20 parts per billion of lead against a federal action level of 15, one sample carried BPA at 87 ppb, and phthalates turned up in 56% of the hoses, including 3 of the 10 labelled safe for drinking water. (Ecology Center, 2016.) Those were hoses sold in 2016 and water that had sat for two days, so be fair to the 1975 nozzle. But the modern parent buying the filtered bottle is not being squeamish. She is being right.

The five-second rule has been tested properly, which almost nothing in this argument has. A laboratory at Rutgers dropped watermelon, bread, buttered bread and gummy sweets onto steel, tile, wood and carpet at under a second, 5 seconds, 30 and 300, 2,560 measurements in all. Transfer happened instantly in every combination, and the wet food picked up as much as 97%. Moisture and surface mattered. Time barely did. (Applied and Environmental Microbiology, 2016.)

Hand sanitiser cannot be the villain, on dates alone. Purell was invented in 1988 and shops would not stock it for consumers until 1997, by which time childhood asthma and allergy had been climbing for over a decade. (History News Network.) It is a symbol of a sealed world, not a cause, and I have caught myself letting it play both parts.

And the friendly soil bacterium everyone mentions, Mycobacterium vaccae, has been through a proper trial in people. 210 patients with advanced lung cancer got it alongside chemotherapy and 209 did not. Median survival was 223 days against 225. Quality of life held up better, which matters. The survival line is flat. (Annals of Oncology, 2004.)

The other ledger

There is a column on the far side of that Tuesday that nostalgia never opens.

Before the vaccine arrived, invasive Haemophilus influenzae type b ran at about 20,000 cases a year in American children, meningitis in half to two thirds of them. Roughly 1 child in 200 got it before their fifth birthday. Between 3% and 6% of the meningitis cases died with correct treatment, and 15% to 30% of the survivors came out with hearing loss or permanent neurological damage. It is now down by more than 99%, and in 2018 there were 38 cases in the whole country. (CDC Pink Book, chapter 8.)

That is the bottle going round the step. Four mouths, one bottle, in a country where 1 child in 200 was going to get bacterial meningitis before they started school.

What the afternoon actually was

Both things came through the same door, and the boy chose neither. He was not taking a treatment and his mother was not neglecting him. He was simply outdoors in a world that had not yet been tested, and when the testing started it found a teacher and a neurotoxin sitting in the same handful of dirt. We pulled out the lead, which was the right call and is the single greatest public health achievement of his lifetime. We also sealed the house, and that bill arrived later, in a different currency, and is still being argued over.

The farm evidence is the piece to take seriously. The rest of that Tuesday is a good story, and I would rather tell you where the story runs ahead of the evidence than let it run.

Two things worth knowing if this is the first page of mine you have read. The allergy science itself, the hygiene hypothesis and what became of it, the peanut trial, the Amish work and the studies that argue against all of it, is laid out in full on the page for 70s Americans Didn’t Have Allergies. And the number you will have heard, 1 in 13 American children with a food allergy, comes from a survey of 38,408 households in which only 61% had a confirmed diagnosis. It is not a CDC figure, whatever you have been told.

The video this comes from: 6 Disgusting Reasons 70s Kids Never Got Allergies · the channel

A page like this goes up within minutes of each new video. Free, and it stays free.

Here is the figure that did not make the script. In 1976, when the Social Security Administration went and counted what older Americans were actually living on, 26% of units aged 65 and over had any private pension income at all. 94% had a Social Security cheque. An aged unit is a married couple or a single person, and the arithmetic does not soften: three in four of the people already retired in the year I was describing were living without the pension the video treats as the era’s standard equipment. (Income of the Population Aged 55 and Older, 1976.)

The man on the dock existed. He was a minority, and I told you he was the norm.

This page is everything I found while building that video, including the places where what I found argued with me. The sources are grouped under the claim each one belongs to, and the section at the bottom is the one to read if you read only one.

The video: Retirement at 62 Didn’t Die. It Was Killed. · the channel

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The pension most people did not have

Coverage and receipt are two different things, and the gap between them is where the nostalgia lives. At the high-water mark, somewhere between 1975 and 1980, roughly four in ten private-sector workers were participating in a defined benefit plan. Participating is not the same as qualifying. In 1972, only 32% of private plan participants had a vested benefit, meaning a legal right to anything at all if they left. ERISA moved that hard: by 1979 it was 48%. (Vesting of Private Pension Benefits in 1979, Social Security Bulletin.)

Sit with the 1972 number for a second. Two-thirds of the people inside the golden-age pension had not yet earned a penny of it, and the ten-year cliff the video mentions is exactly why. The law that fixed this arrived in 1974, seven years before the 401(k) went live, and it fixed it for the generation that came after the man on the dock.

The plan count is the wrong number

I used the plan count in the video because it reads like a crime scene, and it does: 103,346 plans in 1975, a peak of 175,143 in 1983, down to 56,405 by 1998, and 46,233 in 2023. Run the participant numbers beside it and the shape changes. Active participants in those plans went 27.2 million in 1975, 29.9 million in 1983, 22.9 million in 1998, 11.1 million in 2023. (DOL Private Pension Plan Bulletin, historical tables.)

Between 1983 and 1998 the number of plans fell by 68% and the number of people in them fell by 24%. Most of the plans that vanished in that stretch were small ones, a doctor’s practice or a family firm with a dozen employees. The PBGC insured more than 90,000 small plans in 1985 and fewer than 19,000 by 2002, and small plans have disappeared faster than any other group every year since. (PBGC, Trends in Defined Benefit Pension Plans.) The usual explanation is the cost of complying with ERISA, which falls hardest on an employer with nobody to administer it. The industrial pensions, the ones at the plant and the phone company, were still standing.

Which means the collapse I was describing is not a thing that happened to your father. It is happening now, to you. Half the fall in active participants comes after 1998. The first cohorts to live the whole story are retiring this decade, and defined contribution plans went from 11.2 million active participants in 1975 to 96.4 million in 2023, so nobody has to guess what replaced it.

The paragraph, and how much it can carry

The history is solid. Section 401(k) arrives in the Revenue Act of 1978, written for executive deferrals, debated by nobody. Ted Benna reads it in 1980, sees that it can be turned on ordinary payroll, and launches the first one on 1 January 1981 at his own firm. In 2011 he told CBS News that his creation had become a monster. (CBS News, 29 November 2011.) He has repeated it for fifteen years and he means it.

The causation is where I would push back on my own script. Economists who have tried to measure why firms abandoned defined benefit plans do not find one lever. Aaronson and Coronado, writing for the Federal Reserve in 2005, attribute a large share of the shift to the composition of the workforce and to technical change, with the pattern varying by industry in a way a single tax paragraph cannot explain. (FEDS 2005-17.) Manufacturing shrank. Union density fell. Workers changed employers more often and a portable account suited them better. All of that was happening with or without Benna.

The paragraph is a cause. I called it the cause, and it is not.

What 1983 actually did to the number 62

This is the correction I care most about, because it is in the title. The 1983 amendments did not abolish retirement at 62. The earliest eligibility age is still 62 today, unchanged since 1961, and anybody can walk in and claim tomorrow.

What changed is the price. When the full retirement age was 65, claiming at 62 paid 80% of your primary insurance amount. With the full retirement age at 67, which applies to everyone born in 1960 or later, claiming at 62 pays 70%. (SSA, benefit reduction for early retirement.) Same door, same age, 10 percentage points less on the other side of it, for life.

That is a sharper sentence than the one I wrote, and it is the version I would use again. Retirement at 62 was not killed. It was repriced, quietly, by a Congress that knew a benefit cut is easier to pass when it arrives as an actuarial table.

The retirement age itself

The Center for Retirement Research tracks the age at which more than half of a birth cohort has left the labour force. For men it was 66 in 1962, 64 in 1975, and it bottomed at 63 in 1983 before climbing back to 65 in 2024. For women it went from 53 in 1962 to 63 in 2024. (Average Retirement Age for Men and Women, 1962-2024.)

So the male retirement age fell by about three years across the pension era and has since given back two. The cliff I implied is a slope, and for women it runs the other way entirely, which is a different video and probably a better one.

The savings figure I used

The 185,000 dollars is real and it is narrower than it sounds. It is a conditional median, which means it describes households aged 55 to 64 that have a retirement account, and says nothing about the ones that do not. The Federal Reserve found 54.3% of all American families held a retirement account of any kind in 2022. (SCF 2022 bulletin.) The Center for Retirement Research puts it plainly for older households: only about half of them have a 401(k) at all, and among those that do, the combined 401(k) and IRA median was 204,000 dollars in 2022. (CRR, 401(k)/IRA holdings in 2022.)

So when I said half of households have less than 185,000 dollars, that was wrong in the direction that flatters my argument. Half of the households that have an account have less. Count everybody and the true midpoint is far below it. I should have said so.

The Social Security figure I used

I said 73% of seniors lean on Social Security for most of their income, and that number comes from household surveys. Bee and Mitchell at the Census Bureau matched the survey against tax records and found the survey captures 48% of retirement income for people 65 and over. 46% of the time, somebody drawing retirement income reported none. Median household income for that age group came out 30% higher on the administrative data, 44,400 dollars against 33,800. The share of beneficiaries said to depend on Social Security for 90% or more of their income fell from 36% to 18%. (Do Older Americans Have More Income Than We Think?, Census working paper 2017-39.)

Retirees are poorer than they should be. They are not as poor as the survey says, and the gap is widening, because the money that surveys miss is exactly the money the 401(k) era produces: irregular withdrawals from an account rather than a cheque that arrives on the same day every month.

The five moves, checked

The earnings record on ssa.gov is free and benefits are computed from your highest 35 years, so a missing year is a permanent reduction and correcting it costs nothing.

The claiming figure holds. At a full retirement age of 67, age 62 pays 70% and age 70 pays 124%, and 124 divided by 70 is 1.77, hence 77% bigger. It is guaranteed and inflation-adjusted, and it is still wrong for plenty of people, which is why the video says decide it on purpose rather than telling you to wait.

The unclaimed employer match is the weakest of the five. The number everybody quotes traces to a Financial Engines study from 2015, which is old enough that I would not put a figure on screen, so the script says billions and leaves it there.

The government lookup at lostandfound.dol.gov is real and it is not finished. It was built from a voluntary request to plan administrators plus IRS Form 8955-SSA data, and that form is not updated when somebody closes an account, so it produces false positives as well as gaps. (NAPA, December 2024.) Search it, and if nothing comes up, that is not proof you have nothing.

The fee number comes from the Department of Labor’s own booklet: 0.5% against 1.5% over a 35-year career, and the ending balance differs by about 28%.

What did not survive

The share of retirees collecting a private pension has not fallen. It was 26% of aged units in 1976 and 28% in 2014. (SSA Income of the Aged Chartbook, 2014.) This is the most awkward fact on the page and I have thought about it for a week. The likeliest reading is that pension receipt lags pension coverage by about thirty years, so the flat line describes people who earned their benefits before the freeze, and the fall is in front of us rather than behind. That is still not what the video implies, which is that the loss has already landed.

Old age got dramatically less poor, not more. The poverty rate for Americans 65 and over was 28.5% in 1966 and 9.2% in 2017, a fall of nearly 70%. The supplemental measure, which counts medical costs, puts it at 14.1%, which is the number to argue with. (CRS, Poverty Among the Population Aged 65 and Older.) Whatever was taken away, this was not taken away, and it happened because the 1972 amendments tied Social Security to inflation, rather than because of anything a company did.

Retirement risk is not a straight line up. The National Retirement Risk Index, which estimates the share of working-age households that will not maintain their standard of living, read 31% in 1983, rose to 53% in 2010, and came back down to 39% in 2022, the lowest since 2004. (CRR.) The long trend is bad. The recent trend is not, and anyone drawing a single descending arrow from 1975 to today is drawing from memory.

The 2 trillion dollars in lost accounts is a model, not a count. It comes from Capitalize, a company whose business is moving old 401(k) accounts, and it is built from Form 5500 filings and estimated abandonment rates. (Capitalize, The True Cost of Forgotten 401(k)s.) The order of magnitude is probably right. The precision is a press release.

And the 1970s pension broke its promises too. Bethlehem Steel and United Airlines handed theirs to the federal insurer, which pays a capped benefit, and thousands of people found out in their sixties what capped meant. A 401(k) has never done that to anyone, because there is nothing in it to default on. That is the one argument for the new deal I cannot get around, and I left it in the video for that reason.

The video this comes from: Retirement at 62 Didn’t Die. It Was Killed.

Carry that lunchbox into most American schools today and it does not get through the door. Peanuts are banned outright in a great many of them, tree nuts with them, and in some the list runs on through dairy, eggs and wheat. Somewhere between those two lunchboxes, in a single lifetime, the food a child could safely bring to school became a matter for policy.

This page is everything I found while trying to work out what happened, and it starts with a problem I could not get around.

The video: 70s Americans Didn’t have allergies · the channel

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The number that does not exist

Nobody measured food allergy in American children in the 1970s. The first serious American attempt came in 1987, when Bock followed 480 Colorado children from birth and recorded what actually happened when foods were reintroduced. (Pediatrics 1987;79:683.) The earliest usable American peanut figure comes from 1997. Everything anyone tells you about how rare this was when you were at school, including what I told you, is reconstructed from an absence of attention rather than from a count.

The National Academies put it carefully and the exact wording matters: “Although a general perception that food allergy is increasing exists, especially in westernized countries, very few studies support this likely change.” (National Academies, 2016, chapter 3.) They think the increase is likely. They also think almost nobody has demonstrated it.

That does not make the story wrong. It makes the defensible version narrower than the popular one, and the narrower version is still worth your time. At the end of this page there is a section on the papers that went against me, and that is the one to read if you only read one.

What can actually be measured

The figure you will have heard is 1 in 13 American children, which is 7.6%, and it comes from a survey of 51,819 households covering 38,408 children, where parents reported what their children had. Of those children, 61% had at least one allergy a physician had confirmed. (Gupta and colleagues, Pediatrics 2018.) The CDC’s own National Health Interview Survey, which asks specifically about diagnosed food allergy, gives a lower number: 5.8% in 2021, and 5.3% in 2024, which the CDC frames as about 1 in 20. Neither figure comes from feeding children the food and watching what happens, which is the only way to be certain.

If you see “1 in 13, according to the CDC”, the attribution is wrong. It is not a CDC number.

Peanut allergy in children did roughly triple. The same telephone survey run three times found self-reported childhood peanut allergy at 0.4% in 1997, 0.8% in 2002 and 1.4% in 2008. (Sicherer and colleagues, J Allergy Clin Immunol 2010.) Two things sit alongside that. Across all ages, peanut or tree nut allergy was 1.4% in 1997 and 1.4% in 2008, unchanged, so the rise is a children’s finding rather than a population one. And the response rate fell across the series from 67% to 52% to 42%, which matters more than it sounds, because the households that still answer a telephone survey about allergies are disproportionately the households that have one.

Emergency visits climbed steeply. In Illinois, paediatric emergency visits and hospital admissions for food-induced anaphylaxis went from 6.3 to 17.2 per 100,000 children between 2008 and 2012. (Dyer and colleagues, Ann Allergy Asthma Immunol 2015.) Every trend figure of this kind is drawn from billing codes, and the authors say plainly that they cannot separate a real rise in reactions from a change in how reactions get coded. Recognition, epinephrine availability and school policy all changed across the same window.

The hygiene hypothesis, and what became of it

David Strachan published two pages in the BMJ in 1989 showing that hay fever fell as the number of older siblings in a household rose, using the 1958 British birth cohort. (BMJ 1989;299:1259.) He was writing about hay fever and eczema rather than food allergy. He did not use the phrase hygiene hypothesis, which others attached later, but the word hygiene is in his title and the cleanliness idea was his: he pointed at declining family size, better household amenities and higher standards of personal cleanliness reducing cross infection between young children. He also found a weaker trend with younger siblings, which is part of why the older-sibling infection mechanism never held up.

Here is the part I would want if I were watching. The version I gave you, that we made our homes too clean, is the version the field itself has abandoned. The infection mechanism did not survive testing. Specific childhood infections, day care, pets and measles vaccination all gave inconsistent or null results. The researchers who built this area now argue that there is no confirmed evidence of a link between personal or household cleanliness and allergic disease, and that the popular framing does active harm by discouraging hand washing. (Bloomfield and colleagues, Perspectives in Public Health 2016.)

What replaced it is about losing contact with ancestral microbes through diet, antibiotics, birth mode and indoor living, and it goes by Old Friends or the biodiversity hypothesis rather than by hygiene. Writing with Perkin in 2022, Strachan said no mechanism had emerged as robust and described the mechanism behind his own family-size finding as a riddle wrapped in a mystery inside an enigma. The association is solid. What causes it is what nobody has pinned down. (Frontiers in Allergy 2022.)

The peanut advice that ran backwards

In 2000 the American Academy of Pediatrics advised that infants at high risk of allergy should avoid cow’s milk until one, eggs until two, and peanuts, tree nuts and fish until three. (Pediatrics 2000;106:346.) In 2008 it withdrew that advice, concluding there was insufficient evidence to justify delaying any of it beyond four to six months. (Pediatrics 2008;121:183.)

Then the trial. 640 infants with severe eczema, egg allergy, or both, randomised either to eat peanut or to avoid it. Among those who started with a negative skin test, 13.7% of the avoiders had peanut allergy at five years against 1.9% of the eaters. Among those who started with a positive test, 35.3% against 10.6%. (Du Toit and colleagues, NEJM 2015.)

The result is as clean as nutrition research gets. The story built on top of it needs care. The trial studied high-risk infants, the 2000 advice was aimed at high-risk infants, and the advice was withdrawn seven years before the trial reported. So the line running from a guideline to a national epidemic is a plausible narrative rather than a demonstrated one, and I should have said so more plainly than I did.

Birth

American caesarean rates went from about 5.5% of deliveries in 1970 to 16.5% by 1980. (Placek and Taffel, Public Health Reports 1980, for the 1970 figure; Placek and Taffel, AJPH 1987, for 1980.) In the birth certificate data they crossed 20% in the early 1980s, reached 22.8% in 1989, fell back to 20.7% by 1996, and then climbed again to 32.4% in 2024, where they have sat for years. (Births: Final Data for 2024.) Note the dip in the middle. That curve is not the smooth climb people draw alongside a rising allergy line.

Caesarean birth does change which bacteria colonise a newborn, and that is not seriously disputed. In 1,679 samples from 596 British infants, caesarean birth disrupted transmission of the mother’s Bacteroides strains and left hospital-associated organisms in their place. (Shao and colleagues, Nature 2019.) That study measured no allergy outcomes at all, which is worth holding on to, because it is the paper most often cited for a claim it never tested.

Antibiotics

In three large American health plans in 2009 and 2010, children aged between three and twenty-four months were the heaviest users of antibiotics of any age group, at between 0.91 and 1.70 dispensings per child per year depending on the plan. (Vaz and colleagues, Pediatrics 2014.) In the higher-prescribing plans that works out at roughly two to three courses before a second birthday, and rather fewer in the lowest. Those data are now sixteen years old and paediatric prescribing has come down since.

The farms

Two communities in the American midwest, both plain-living, both large families, both raised without television. The Amish farm one family to a farm, largely without machinery, and their children are around animals every day. The Hutterites farm communally and industrially, on a scale that keeps children away from the animals.

Asthma in Amish children runs at 5.2% against 21.3% in Hutterite children. Allergic sensitisation runs at 7.2% against 33.3%. House dust from Amish homes carried 4,399 endotoxin units per square metre against 648, nearly seven times as much. (Stein and colleagues, NEJM 2016.) When the Amish house dust was put into the noses of mice, it suppressed airway reactivity, and that protection vanished in mice lacking the core innate immune signalling machinery, which is the part that turns a correlation into something closer to a cause.

Two things to keep in proportion. Only 30 children from each community were immune-profiled, and the prevalence figures come from earlier community surveys rather than from those 60 children.

A second comparison sharpens it. Amish households showed allergic disease at 26.4% against 46.7% in Old Order Mennonite households. (Tantoco and colleagues, Ann Allergy Asthma Immunol 2018.) Both communities are plain-living and most families in both live on farms. What separates them is scale and machinery: the Amish farms are smaller, with fewer animals, less mechanised, and raw milk is drunk more often. The protection tracks how the farming is done rather than whether the family is plain.

What did not survive

Blood tests in American children did not show the increase. Comparing 7,896 children aged 6 to 19 across two national surveys, food sensitisation measured by IgE came out at 24.3% in 1988 to 1994 and 21.6% in 2005 to 2006, a difference whose confidence intervals overlap. The authors’ conclusion was a null: sensitisation did not increase, contrary to what they expected. The one change that was significant went the other way, with shrimp sensitisation falling from 11.2% to 6.1%. (McGowan and colleagues, J Allergy Clin Immunol Pract 2016.) Sensitisation is not the same as clinical allergy and the window starts in 1988 rather than 1975, so this does not settle the question. It is still the most inconvenient dataset in the field, and it is laboratory measurement rather than a survey.

The antibiotic link mostly disappears between siblings. Across a Swedish national cohort, foetal antibiotic exposure carried a hazard ratio of 1.28 for later asthma. Compare brother with brother inside the same family and it falls to 0.99. For antibiotics given for urinary or skin infections, which have nothing to do with the airway, the population figure of 1.54 falls to 0.85. (Örtqvist and colleagues, BMJ 2014.) The likeliest reading is that families prone to asthma are also families whose babies get prescribed more antibiotics, and that early wheeze is often treated as a chest infection before anyone calls it asthma.

The largest recent caesarean study found nothing. In 74,639 Japanese children, the adjusted odds ratios for wheeze, eczema, asthma and atopic dermatitis were 0.98, 0.99, 0.95 and 1.02. (Scientific Reports 2025.) Two limits: everything was assessed at one year of age, and food allergy was not among the outcomes. Where an effect is found elsewhere it is usually a 20% to 30% relative increase, and in the best-designed study it appeared only in children whose gut bacteria still looked caesarean at their first birthday. (Stokholm and colleagues, Science Translational Medicine 2020.)

The sibling effect that started all of this is heavily confounded. A Finnish total-population analysis of 324,306 children with siblings, comparing children within the same family, found that confounding accounted for as much as 75% of the apparent protection, most of all for asthma and eczema medication. A birth-order effect survived across every outcome they measured, so something real is there. It is a good deal smaller than the raw gradient suggests. (Luukkonen and colleagues, European Journal of Epidemiology 2024.)

And there is still no 1970s number. Nobody counted. That is where this page started and it is where it ends.

The video this comes from: 70s Americans Didn’t have allergies

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The chart of American obesity barely moves through the 1960s and the 1970s. It reads 13.4% at the start of the 1960s and 15.0% by the end of the 1970s, two decades of a line that will not go anywhere. Then, somewhere around 1980, it bends, and it has not stopped bending since. That bend is what these three videos are about, and it is a strange thing to sit and look at, because a population does not lose its willpower in a single decade. Something around those people changed, and it changed fast enough to show up in a national chart.

This page is every study behind that argument, grouped under the claim each one supports, with a line on what each actually found. At the end there is a section on the papers that went against me. Read that one first if you only read one, because it is where the findings sit that I could not make fit.

The videos: 70s Americans Were Slim. Four Decisions Changed That · America Made You Fat After 1980 · America Gave You BELLY FAT After 1975 · the channel

How much changed

Adult obesity sat at 14.5% in the early 1970s, and either side of that the 1960s and 1970s readings run between 13.4% and 15.0%. From roughly 1980 it climbed, and it is around 40% now. The most severe category went from 1.3% of adults, about 1 in 77, to something close to 1 in 10. The endpoints get quoted constantly. The shape is the part worth holding on to: two decades of a flat line, and then a bend. (CDC NCHS, NHANES: prevalence.)

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The average American man weighed 173.4 lb in 1971 to 1974 and weighs 199.1 lb now. Over the same half century his height did not change at all: 68.9 inches then, 68.9 inches now. Every pound of the difference is mass. One caution I will state rather than hide: the old figure covers men aged 20 to 74 and the modern one covers men aged 20 and over, so the two are not measured on identical populations. (CDC Advance Data 347; NCHS Vital and Health Statistics Series 3, No. 50, 2021 to 2023 data.)

Waists have grown faster than weight. Abdominal obesity moved from 46.4% to 54.2% across the twelve years between the 1999 to 2000 and 2011 to 2012 survey cycles, with the average waist up 3 cm, over a stretch when BMI shifted a good deal less. (Ford and colleagues, JAMA 2014.)

There is one number I will not put on screen. No clean measurement of a 1970s male waist exists, so the comparison everyone wants cannot be made from the data. What can be said is that the average American man’s waist now measures 103.0 cm, or 40.6 in, which has moved past the clinical high-risk line of 40 in for men and 35 in for women rather than merely reaching it. (NCHS Series 3, No. 50; thresholds from NCEP ATP III.)

Why the belly is the part that matters

Fat around the organs behaves differently from fat under the skin, because it drains into the liver through the portal vein and delivers free fatty acids and inflammatory signals straight to it. That is the mechanism behind the insulin resistance and the fatty liver, and it is why the location matters more than the total. (Item and Konrad, Obesity Reviews.)

Imaging work at Imperial College London put two men of the same build side by side, both at a BMI of 25, and found 5.86 litres of internal fat in one and 1.65 in the other. More than three times as much, at the same weight, in two men a doctor would have waved through. The wider MRI study those men came from put roughly 14% of men and 12% of women in that position. I treat that share cautiously, not because the study is weak but because it drew on volunteers rather than a nationally representative sample. (Thomas and colleagues, Obesity 2012.)

Fatty liver disease now affects something like one American adult in three. Saying it was unheard of in the 1970s overstates what anyone can know, since the condition was not named until 1980, so undescribed is the fairer word.

The measure that survives everything is a waist under half your height. It beats BMI for picking up cardiovascular risk factors, and it adjusts for body size on its own, which is why it holds across populations where a fixed threshold in inches falls apart. (Ashwell and Gibson, Obesity Facts 2009; for the mortality evidence specifically, Ashwell, Gunn and Gibson, Obesity Reviews 2012.)

What went into the food

Twenty people were fed in a hospital, half their time on ultra-processed food and half on food cooked from ingredients, with the two diets matched for presented calories, energy density, sugar, sodium, fibre and broad macronutrient split. They could eat as much as they liked. On the processed diet they ate 508 calories a day more and gained 0.9 kg. On the other they lost the same. (Hall and colleagues, Cell Metabolism 2019.)

Twenty people, two weeks each, and the match was not perfect: the processed arm came in at 14% protein against 15.6%, which may account for as much as half the difference. That is the best-designed evidence anyone has produced on the question, and it remains a small study. I quote it because it removed the usual excuses, not because 20 people settle anything.

Ultra-processed food now supplies over half the calories American adults eat, and about 62% of what their children eat. (CDC NCHS Data Brief 536, 2025.)

Portions grew by a factor of two to five. A McDonald’s soda went from 7 oz in 1955 to 32 oz by 2006, and the fries from 2.4 oz to 6. (Young and Nestle, Journal of Public Health Policy 2007; the two to five range is from their American Journal of Public Health paper of 2002.) Daily intake rose from 1,803 calories to 2,374, and the number of times a day people ate went from 3.8 to 4.9. The portions did the early work and the extra eating occasions did the later work. (Duffey and Popkin, PLoS Medicine 2011.) The share of adults who snack at all went from 59% in 1977 to 1978 up to 90% in 2007 to 2008. (USDA Agricultural Research Service, Dietary Data Brief No. 4, 2011.)

The oils changed too, and the consumption figures are not in doubt. Crisco arrived in 1911 and went from 2.6 million pounds sold in 1912 to 60 million by 1916. Across the twentieth century, soybean oil availability rose more than a thousandfold, and linoleic acid, which is what those oils mostly deliver, went from 2.79% of American calories to 7.21%. (Blasbalg, Hibbeln and colleagues, American Journal of Clinical Nutrition 2011.) The hydrogenation that made those oils solid also produced trans fats. The FDA ruled partially hydrogenated oils unsafe in 2015, most uses had to stop by June 2018, and products already manufactured were allowed to be distributed until January 2021. Whether the seed oils themselves harm you is a separate question, and I come back to it at the end.

What we drank

When 32 overweight and obese adults aged 40 to 72 were given a quarter of their daily calories as fructose for 10 weeks, the liver’s own fat production climbed by more than 80% and fat around the organs rose with it. The same calories as glucose did neither. (Stanhope and colleagues, J Clin Invest 2009.) A quarter of daily calories as pure fructose is a dose nobody drinks, so that study demonstrates a mechanism rather than an everyday effect.

In the Framingham cohort, people who drank a sugary soda every day gained about 194 cubic centimetres more visceral fat over 6 years than people who did not. (Ma and colleagues, Circulation 2016.) Observational, so read it as a pattern rather than a proof.

Calories in liquid form barely register. Given the same calories as a drink or as something to chew, people compensate for the solid and eat less later, and they do not compensate for the drink. (DiMeglio and Mattes, International Journal of Obesity 2000.)

Among more than 5,700 adults in the Oxford Biobank, the heaviest drinkers carried over 10% more visceral fat than those drinking less. (International Journal of Obesity 2026.)

What stopped

Work stopped burning roughly 140 calories a day for men and 124 for women. Jobs requiring moderate physical activity fell from about 48% of American employment in 1960 to about 20%. (Church and colleagues, PLoS ONE 2011.)

That is a modelling estimate, and the model under-predicts the weight Americans actually gained by around 2 kg. My view, and I hold it more firmly the longer I read on this, is that the desk-job story is weaker than almost everyone using it believes. The gap is the interesting part. Something the movement figures cannot account for is doing the work, and the food is the obvious candidate. Sitting is a contributor. It is not the cause.

Sitting rose from 5.5 to 6.4 hours a day between 2007 and 2016, which is a short window at the recent end of the story rather than the whole arc. (Yang and colleagues, JAMA 2019.) Americans walk about 5,000 steps a day. Amish men average 18,425 and Amish women 14,196, and obesity in that community runs at roughly 4%, which is none of the men and 9% of the women. (Bassett and colleagues, 2004 and 2010.) Children walking or cycling to school fell from 48% in 1969 to 13% in 2009. (National Household Travel Survey.)

Muscle is where most of the sugar in your blood gets cleared. (DeFronzo and Tripathy, Diabetes Care 2009.) It also falls by 3% to 8% a decade after 30 (Volpi, Nazemi and Fujita, Current Opinion in Clinical Nutrition and Metabolic Care 2004), which between them is why an unchanged diet lands differently at 55 than it did at 25.

What happens at night

Four hours of sleep for two weeks added 308 calories a day and 11% more visceral fat, in a crossover study of 12 people. (Covassin and colleagues, JACC 2022.) Two nights of it dropped leptin by 18%, raised ghrelin by 28%, and raised reported hunger by about 24%. (Spiegel and colleagues, Annals of Internal Medicine 2004.)

Visceral fat also carries between two and four times the density of cortisol receptors that fat under the skin does, which is the mechanism underneath the old observation that stress lands on the middle.

About a third of American adults now sleep under 7 hours. I claim that figure and the hormone link. I do not claim that Americans sleep less than they did in 1975, because that particular trend is disputed and I have not seen it settled. (CDC NCHS.)

The parts I flagged as unsettled, and why

Several common medications push weight up, including some antidepressants, beta-blockers, antihistamines, antipsychotics, steroids and the older diabetes drugs. Effect sizes vary enormously by drug and by person. Nothing on this page is a reason to stop taking anything, and if a medication is part of your picture that is a conversation with the person who prescribed it.

Prozac reached the market in 1988 and antidepressant use rose roughly fourfold between the early 1990s and the late 2000s, with about one adult in eight taking one today. (CDC NCHS Data Briefs 76 and 377.) That is timing, and timing is not cause. I said so in the video and I am saying it again here, because it is the claim on this page most likely to be repeated without the caveat attached.

Obesogens, the industrial compounds proposed to promote fat storage, are genuinely unsettled. The literature is early. I say so rather than borrowing its authority quietly.

What actually shifts it

Aerobic work cut visceral fat even when body weight did not change, and low-intensity work did not. (Vissers and colleagues, 2013.) Each extra 10 grams a day of soluble fibre tracked with a 3.7% smaller gain in visceral fat over five years, while total and insoluble fibre showed no such association. (Hairston and colleagues, 2012.) And when people lose weight, visceral fat falls faster in percentage terms than the fat under the skin, though no intervention targets it specifically and the two come off together. (Merlotti and colleagues, 2017.)

What did not survive

Sit-ups do not shrink a waist. Twenty-four people did seven abdominal exercises, two sets of ten, five days a week for six weeks, and their waist circumference changed by nothing at all. (Vispute and colleagues, 2011.) It is the clearest result on this page and the one most likely to save you money.

Sugar is not the lone villain. Among adults aged 19 to 50, added sugar peaked around the year 2000 and fell by roughly 25%, from 96.6 grams a day to 72.3, and obesity carried on rising straight through the decline. In adults over 50 there was no significant change either way. High-fructose corn syrup set against ordinary table sugar, in a 2022 meta-analysis covering 767 people, produced no significant difference in weight, waist, lipids or glucose, though it did show a rise in C-reactive protein across three of the studies. (Frontiers in Nutrition 2022, PMC9551185.) I keep all of this in the videos. Taking it out would make the story cleaner and less true.

Metabolism does not slow at 40. Total energy expenditure holds close to flat from about 20 to 60 once body composition is accounted for. Whatever changed in middle age, the furnace was not it. (Pontzer and colleagues, Science 2021.) That one changed my mind while I was writing.

Seed oils are half in and half out. The consumption figures above are real and enormous. The harm to health is contested, and I report the first and leave the second open rather than taking the side that would make the story tidier.

One figure came out of a draft. The line that the average person checks a phone 2,000 times a day traces to a 2016 study of 94 Android users watched for 5 days, and it counted touches rather than checks. The 4.5 to 5 hours a day of use is well supported, so that is the number I use now.

Diet soda showed nothing. In the same Framingham data where daily sugary soda tracked with visceral fat gain, diet soda had no association at all. That was not the result I expected when I started.

The videos this comes from: 70s Americans Were Slim · America Made You Fat After 1980 · America Gave You BELLY FAT After 1975