A new study suggests that limiting sugar intake during the first 1,000 days of life—from conception to about age two and a half—may have a lasting protective effect on mental health, reducing the likelihood of developing anxiety in adulthood. The research, led by scientists at the University of Surrey, draws on a unique natural experiment: the sugar rationing that Britain imposed during and after the Second World War.
The United Kingdom maintained strict sugar rationing from 1940 until 1953, capping adult intake at roughly 40 grams per day. This period created a clear divide between those who grew up under these constraints and those who did not, offering researchers a rare opportunity to examine long-term health outcomes.
The study, published in the journal Translational Psychiatry, analysed medical data from more than 45,000 people born between 1951 and 1956. The researchers compared individuals who experienced rationing in utero and up to six, 12, 18, or 24 months after birth, as well as those who were only exposed in the womb, with a group that never faced rationing.
Results showed that those who experienced the longest period of rationing reported a significantly lower preference for sweet foods and a 33% lower risk of developing anxiety in adulthood compared to those who were never rationed. The effect was not limited to anxiety: rationed groups also developed anxiety and depression later in life. The median age of anxiety onset was around 62 years for the long-rationed group, versus 55 years for the never-rationed group.
Why early nutrition matters
The first 1,000 days of life are a critical window for brain development, and nutrition during this period can cause lasting structural changes in the brain, the authors note. Previous research cited in the study suggests that sugar-rich diets can reduce the density and availability of serotonin neurons, which are crucial for mood regulation. Early restriction may protect these pathways, offering a biological explanation for the observed effects.
Hana Navratilova, lead author of the study, said: “Knowing the full impact that sugar can have on our physical and mental health, across our lifespan, could help inform public health policy and reshape our diets.”
Nophar Geifman, professor at the University of Surrey and senior author, added: “Despite increased sugar consumption after rationing amongst participants, early nutritional environments appear to have lasting relevance for mental health.”
The researchers noted that sugar consumption rose rapidly once rationing ended, yet the effects of early restriction persisted for years. This suggests that the timing of sugar exposure may be more important than total lifetime intake.
The findings come as European policymakers grapple with rising rates of childhood obesity and mental health issues. While the study is observational and cannot prove causation, it adds to a growing body of evidence that early-life nutrition has profound long-term consequences. For a continent where dietary habits vary widely—from the Mediterranean diet in Spain and Italy to higher sugar consumption in northern Europe—the implications could be significant.
As young adults across Europe face increasing mental health pressures, this research underscores the importance of early interventions. It also raises questions about current dietary guidelines and the marketing of sugary products to children, a topic that has sparked debate in Brussels and beyond.
While the study focused on the UK, its findings are likely relevant across Europe, where similar post-war rationing policies existed in countries like France and Germany. The authors hope their work will encourage further research into the long-term effects of sugar on mental health and inform public health strategies across the continent.
