In September 1953, Britain did something that turned into one of the most useful accidents in nutrition science.
It ended sugar rationing.
Almost overnight, adults went from eating about 41 grams of sugar a day to about 80. Babies and toddlers got a lot more sugar too.
That sudden switch created a natural experiment.
Children conceived just before the change spent their first 1,000 days on very little sugar. Children conceived a little later didn’t.
Now, seventy years on, a new study in Nature Communications has checked how both groups are ageing. The rationed babies seem to be ageing a little more slowly.
- People exposed to sugar rationing from conception to age two had fewer age-related diseases and lower death rates decades later.
- Their bodies also looked about a year “younger” on several biological ageing measures.
- It adds to growing evidence that the first 1,000 days of life shape long-term health, and that less added sugar early on may matter.
A natural experiment from 1953
What rationing looked like
During and after the Second World War, sugar and sweets were rationed in the UK.
Most people, including pregnant women, got about 8 ounces of sugar a week, plus a small allowance of sweets. Babies under two got no sugar ration at all.
That kept adults to roughly 40 grams of sugar a day or less, and young children to under 15 grams.
Those amounts line up closely with today’s dietary advice.
Why it’s so useful to scientists
Normally, you can’t randomly assign babies to eat more or less sugar for years. It would be unethical and impractical.
But the end of rationing did something similar by accident. Whether a child spent their early life with little sugar depended mostly on when they happened to be born.
Other parts of the diet changed much less. Sugar intake rose by more than 50% after rationing ended, while total calories rose only about 5%.
The study: 64,809 people, seventy years later
Who was included
An international team, led by researchers in Hong Kong and China and including UK experts in Liverpool, used the UK Biobank. That’s a huge health study of adults who gave samples and have been followed through medical records.
They included 64,809 people born around the end of rationing:
| Group | People | Early-life sugar |
|---|---|---|
| Rationed | 40,872 | Conceived or born while rationing was in place |
| Not rationed | 23,937 | Conceived after rationing ended |
What they measured
The team tracked 83 diseases linked to the biological “hallmarks” of ageing, such as heart disease, diabetes and some cancers.
They also looked at deaths from any cause, several “biological age” clocks based on blood tests and DNA markers, and the ages of individual organs.
The results: fewer diseases, slower ageing
Fewer age-related diseases
People who spent their first 1,000 days under rationing had a 9% lower rate of age-related diseases overall.
The pattern held for men and women, across birthplaces and ethnic groups, and whether or not their parents had heart or metabolic disease.
Lower death rates
The rationed group also had a 19% lower risk of dying during follow-up.
About 60% of that difference was statistically explained by their lower rates of age-related disease.
| Outcome | Rationed vs not rationed |
|---|---|
| Age-related diseases | 9% lower rate |
| Death from any cause | 19% lower risk |
| Biological age | About 1.0 to 1.2 years younger |
| Organs that looked youngest | Lung, heart and liver |
Younger on the inside
Across several biological ageing clocks, the rationed group looked about a year younger than their calendar age would suggest.
Blood protein tests pointed to the same story. The researchers found 47 proteins that differed, many linked to known longevity pathways in the body.
Still eating less sugar today
One more intriguing detail: as adults, the rationed group still ate slightly less sugar. It was about 4 grams a day less, a small but measurable difference.
That hints early habits may linger, though it’s too small to explain the whole effect.
More rationing, more benefit
The researchers didn’t just compare two groups. They grouped people by how long they spent under rationing, from only in the womb to the womb plus two years.
The longer the exposure, the stronger the protection tended to be. That kind of dose-response pattern is what you’d expect if early sugar really matters, rather than a quirk of timing.
Why might early sugar matter?
Scientists have long argued that the first 1,000 days, from conception to a child’s second birthday, can “programme” long-term health. The idea has a name: the developmental origins of health and disease.
Much of the evidence comes from famine studies, where severe hunger early in life raised later disease risk. This study looks at the opposite: a moderate cut in one ingredient during a time of adequate food.
The blood proteins offer a clue about the biology.
Pathways linked to longevity, including one called AMPK, were more active in the rationed group. A growth pathway called mTOR, which is linked to faster ageing, looked less active.
That doesn’t prove the mechanism, but it fits with what lab research on ageing has found.
Babies raised under Britain’s sugar rationing later had 9% fewer age-related diseases and a 19% lower risk of death. They also looked about a year younger biologically.
What earlier research found
This isn’t the first study to use the 1953 natural experiment. Together, they paint a consistent picture.
Less diabetes and high blood pressure
A 2024 study in Science used the same approach to look at type 2 diabetes and high blood pressure.
Early-life rationing cut the risk of type 2 diabetes by about 35% and high blood pressure by about 20%. It also delayed their onset by about 4 and 2 years.
Protection started in the womb and grew once babies began eating solid food.
Healthier hearts
A 2025 study in The BMJ looked at heart and circulation problems in 63,433 people.
Those exposed to rationing in the womb and for the first 1 to 2 years had about 20% less cardiovascular disease. Their risk of stroke was about 31% lower, and heart failure about 26% lower.
Fewer early cancers
A 2026 study in The American Journal of Clinical Nutrition looked at cancers diagnosed before age 50.
People exposed to early-life sugar restriction had about a third lower risk of early-onset cancer.
How it fits together
The new study ties these findings together. It suggests early-life sugar exposure may affect the pace of ageing itself, not just one disease at a time.
That’s a bigger claim, and it rests on the same kind of evidence. But the consistency across diabetes, heart disease, cancer and now overall ageing is striking.
How much should you trust this?
Promising. It’s one of the best natural experiments in nutrition, but it’s still observational.
What makes it convincing
- The end of rationing was a sudden policy change, not something families chose.
- The benefits grew with longer exposure, a dose-response pattern that supports a real effect.
- It matches several independent studies of the same natural experiment.
- The authors declared no competing interests.
What makes me cautious
- Nobody measured how much sugar each baby actually ate. Families may have shared rations.
- Other things changed in the 1950s too, such as healthcare and diagnosis. The authors tried to adjust for this, but can’t rule it out completely.
- The rationed group was slightly older when they joined UK Biobank, which the analysis had to account for.
- UK Biobank volunteers tend to be healthier and wealthier than the general population.
- Biological age clocks are useful research tools, but they aren’t perfect measures of how long someone will live.
| This study shows | This study does not show |
|---|---|
| Rationed babies had fewer age-related diseases later | That sugar alone caused the difference |
| They had lower death rates and younger biological ages | Exactly how much sugar is safe for babies |
| Benefits grew with longer exposure | That cutting sugar in adulthood reverses ageing |
| The pattern matches other rationing studies | That the results apply outside the UK |
What this means for you
If you’re pregnant or have a baby or toddler, this is one more reason to go easy on added sugar early on.
- Skip added sugar for babies. Their food doesn’t need it, and early taste habits may last.
- Watch drinks. Juice and sweetened drinks are an easy way for sugar to creep in.
- Read labels on baby and toddler foods. Some snacks marketed to children are surprisingly sweet.
- Don’t panic about the odd treat. Rationing meant low sugar, not zero sugar.
For adults, the World Health Organization advises keeping free sugars to under 10% of daily energy, and ideally under 5%. Its fact sheet on a healthy diet explains more.
The NHS also explains how sugar affects health and which foods to avoid giving babies and young children.
In this talk, longevity researcher Professor Luigi Fontana discusses how sugar in the first 1,000 days may shape lifelong health:
What we still don’t know
- How much sugar is too much for a baby? Rationing gives a rough level, not a precise threshold.
- Does timing matter most in the womb or after birth? Earlier work suggests both, with more benefit once solid food starts.
- Would the same happen today? Modern diets, healthcare and sugar sources are very different.
- What is the biology? The protein changes point to longevity pathways, but the mechanism isn’t proven.
- Can later changes make up for early exposure? Nobody knows yet.
- Does it apply beyond Britain? Other countries’ natural experiments could help test it.
My take: early sugar may leave a long shadow
What I like about this study is how it turns a piece of postwar history into evidence about ageing. Birth timing did the randomising that no ethical trial could.
I’m cautious about the “one year younger” headline. It comes from biological clocks, which are estimates, and the whole study is observational.
Still, when separate studies of the same natural experiment keep finding the same direction of effect, it’s hard to ignore.
It also matters that the rationing diet wasn’t extreme. People weren’t starving; they simply ate far less added sugar than we do now.
The first 1,000 days look like a good time to keep sugar low.
Paper: Early life sugar rationing and ageing related diseases, biological ageing and mortality
Published: Nature Communications, 2026-07-31
Study: Natural experiment using the end of UK sugar rationing in 1953, within the UK Biobank cohort
Who: 64,809 UK adults born around the end of rationing
Funding: Guangzhou Municipal Research Fund; the authors declare no competing interests
Evidence: Promising — a strong natural experiment, but observational and based on birth timing rather than measured sugar intake