A study published in the BMJ looks at the impact of sugar rationing and long term cardiovascular health.
Prof Azeem Majeed FMedSci, Professor of Primary Care and Public Health, Imperial College London, said:
"This study uses the end of UK sugar rationing in 1953 as a natural experiment to investigate the effects of early-life sugar restriction on long-term cardiovascular outcomes such as heart attacks and strokes, drawing on participants from the UK Biobank cohort who were born around that time. The press release captures the key findings accurately, highlighting the dose-response relationship with longer exposure to rationing linked to progressively lower risks without overstating causality.
"The research is methodologically strong with robust statistical adjustments for demographics, genetics, parental health, and geography.
"A key limitation is the reliance on historical rationing as a proxy for actual sugar intake, which wasn't directly measured for each participant.
"Overall, the findings align well with prior evidence from animal models and human studies on foetal programming. The findings also reinforce WHO guidance on avoiding foods and drinks high in added sugars during infancy and complementary feeding to reduce future cardiometabolic risks."
Dr Stephen Burgess, Statistician at the MRC Biostatistics Unit, University of Cambridge, said:
"Studies investigating links between diet and health have a fundamental difficulty. Are individuals who consumed less sugar in early life healthier because of a causal protective effect of sugar consumption? Or are individuals who consumed less sugar healthier because of a related factor, such as family wealth or lifestyle?
"This study aims to differentiate between these two possibilities by linking disease risk not with an individual's own sugar consumption, but with whether they were conceived during the period of sugar rationing following the Second World War. As neither individuals nor their families chose whether they experienced sugar rationing or not, such a comparison should be unaffected by many alternative factors, such as lifestyle.
"Accounting for trends in disease rates, the investigators found that the generation conceived during the period of sugar rationing had 20% lower risk of cardiovascular disease than the generation born after sugar rationing, and that this difference in risk was largely attributable to diabetes and high blood pressure.
"A plausible explanation for this finding is a true causal protective effect of lower sugar consumption on cardiovascular disease risk. However, this is not the only possible explanation. For instance, it could be that there was another generational shift around the ending of sugar rationing that is the responsible factor. However, similar differences in disease risk were not observed for diseases that are not thought to be consequences of early life sugar consumption."
Prof Gunter Kuhnle, Professor of Nutrition and Food Science, University of Reading, said:
Does the press release accurately reflect the science?
"Unfortunately, it does not. The press release - and the paper - suggest that there is a link between early life sugar intake and health in later life, but the study is not designed to show that. Due to the absence of actual intake data, the authors rely on environmental data which does not provide any information about actual, individual sugar intake. It is notable that the paper refers to exposure to sugar rationing and not actual sugar intake.
"The press release implies a beneficial effect of sugar rationing in early years, however, this ignores any other circumstances that coincided with sugar rationing which need to be explored and excluded first. It is therefore highly speculative.
Is this good quality research? Are the conclusions backed up by solid data?
"Measuring sugar intake is very difficult, as people tend to underreport intake - and reliable data can only be obtained by measuring intake using biomarkers. Estimating sugar intake in the first 1000 days is even more difficult, as one would have to rely on the recollection of parents. The authors therefore used the food environment as a proxy to infer sugar intake. While the paper clearly states that they are interested in exposure to sugar rationing, both the press release and parts of the paper imply that exposure to sugar rationing is largely equivalent to sugar intake - but this is an assumption that is not supported by any evidence. Sugar rationing will have an impact on sugar intake, but this impact will vary largely between individuals - it is therefore impossible to make any inferences about sugar intake of individuals.
"The data from food surveys are also subject to misreporting as sugar intake is very often underreported.
How does this work fit with the existing evidence?
"There is no reliable evidence of the impact of sugar intake in early life on health outcomes in later life.
Have the authors accounted for confounders? Are there important limitations to be aware of?
"The authors infer sugar intake from information about the food system - but do not estimate actual sugar intake.
What are the implications in the real world? Is there any overspeculation?
"It is impossible to separate the effects of sugar rationing from other policies at the time - it is therefore overspeculation. It is not suitable to develop policy."
Prof Tom Sanders, Professor emeritus of Nutrition and Dietetics, King's College London, said:
"This study reports that babies exposed to sugar rationing were at lower risk of developing diabetes and cardiovascular disease as adults. The data is based on differences in risk of long term adult ill-health in children born between 1951 and 1956 in relation to exposure in the first 1000 days post conception. The paper used a cliff edge of September 1953 for the end of sugar rationing. However, this is inaccurate: rationing for canned and dried fruit, chocolate biscuits, treacle, syrup and jellies (significant dietary source of sugar) stopped in May 1950, sweets and confectionery in Feb 1953 and table sugar in Sept 1953. There was a rush to buy sweets well before September 1953 when table sugar was derationed.
"There were no measurements of maternal dietary intake or that of the infants (so increases in sugar are just presumed). Orange juice concentrate was available to both mothers and babies as Welfare Food until l957. The proportion of babies that were breastfed was high - 58% (as reported by the of the participants of the Biobank Study) were breastfed and it was normal at that time to exclusively breastfeed up to six months. Increased availability and promotion of breastmilk substitutes were contributing to the decline in duration of breastfeeding over the study timeframe. Duration of breastfeeding may be an important confounder.
"Sugar intake does not affect breastmilk composition. However, in the weaning period, rusks were commonly used and dummies often contained sugary fluid.
"Food rationing was not confined to sugar and included significant sources of dietary energy, saturated fat and salt in the diet (later linked to CVD) until 1954 (cheese and fats stopped in May 1954, and meat, bacon and ham in July 1954). Consequently, it could also be argued that children born in the period 1951-September 1953 would have had a lower exposure to saturated fat and salt as toddlers than those born later.
"The conclusion of this study is speculative as so many other factors were changing in this period. Studies such as these only show associations that may or may not be causal."
'Exposure to sugar rationing in first 1000 days after conception and long term cardiovascular outcomes: natural experiment study' by Jiazhen Zheng et al. was published in the BMJ at 23:30 UK time on Wednesday 22 October 2025.
Ongoing collaboration with Mars on health effects of flavan-3-ol."
Prof Tom Sanders: "I have received grant funding for research on vegans in the past. I have been retired for 10 years but during my career at King's College London, I formerly acted as consultant for companies that made artificial sweeteners and sugar substitutes.
I am a member of the Programme Advisory Committee of the Malaysia Palm Oil Board which involves the review of research projects proposed by the Malaysia government.
I also used to be a member of the Scientific Advisory Committee of the Global Dairy Platform up until 2015.
I did do some consultancy work on GRAS affirmation of high oleic palm oil for Archer Daniel Midland more than ten years ago.
My research group received oils and fats free of charge from Unilever and Archer Daniel Midland for our Food Standards Agency Research.
I was a member of the FAO/WHO Joint Expert Committee that recommended that trans fatty acids be removed from the human food chain.
Member of the Science Committee British Nutrition Foundation. Honorary Nutritional Director HEART UK.
Before my retirement from King's College London in 2014, I acted as a consultant to many companies and organisations involved in the manufacture of what are now designated ultraprocessed foods.
I used to be a consultant to the Breakfast Cereals Advisory Board of the Food and Drink Federation.
I used to be a consultant for aspartame more than a decade ago.
When I was doing research at King' College London, the following applied: Tom does not hold any grants or have any consultancies with companies involved in the production or marketing of sugar-sweetened drinks. In reference to previous funding to Tom's institution: £4.5 million was donated to King's College London by Tate & Lyle in 2006; this funding finished in 2011. This money was given to the College and was in recognition of the discovery of the artificial sweetener sucralose by Prof Hough at the Queen Elizabeth College (QEC), which merged with King's College London. The Tate & Lyle grant paid for the Clinical Research Centre at St Thomas' that is run by the Guy's & St Thomas' Trust, it was not used to fund research on sugar. Tate & Lyle sold their sugar interests to American Sugar so the brand Tate & Lyle still exists but it is no longer linked to the company Tate & Lyle PLC, which gave the money to King's College London in 2006."