Sugar Restriction at Early Ages Mitigates Genetic Obesity Risk

07/08/2026
Summary of working paper 35005

This figure is a line chart with error bars titled "Early-Life Sugar Exposure and Adult Obesity, UK," showing the difference in probability of adult obesity by genetic risk group relative to when individuals were conceived, before and after the end of UK sugar rationing. The y-axis is labeled "Difference in the probability of adult obesity relative to individuals conceived in the first six months after rationing ended" and ranges from −10.0 pp to +5.0 pp. The x-axis is labeled "Time between conception and the end of sugar rationing" and ranges from −33 months to 18 months, with a note that negative values indicate individuals conceived in utero before rationing ended. The legend distinguishes between individuals with low genetic risk for obesity, shown in blue, and individuals with high genetic risk for obesity, shown in gray; a vertical dashed line marks the point when sugar rationing ended (September 1953), dividing individuals conceived before and after that date. The figure shows that for individuals with low genetic risk, the obesity probability difference stays relatively flat and close to 0.0 pp across all time points; for individuals with high genetic risk, the difference starts around −5.0 pp for those conceived 27–33 months before rationing ended, rises steadily toward 0.0 pp as the conception date approaches the end of rationing, and remains close to 0.0 pp for those conceived after rationing ended, with confidence intervals that are wider for earlier conception times and narrow closer to the rationing end date. A note on the figure reads: "The coefficients that are shown at '0 months' reflect the impact on the cohort that was born between July and December 1954 and therefore conceived between 0 and 6 months after sugar rationing ended." The source line reads: "Researchers' calculations using data from the UK Biobank."

During World War II, the United Kingdom’s sugar rationing policy limited average daily sugar intake to 40 grams for adults and 15 grams for children. When rationing ended in September 1953, sugar consumption rebounded rapidly. In Early-Life Sugar Restrictions Reduce Genetic Disparities in Adult Adiposity (NBER Working Paper 35005), Tadeja Gracner, Claire Boone, Patrick Turley, and Paul Gertler use this dietary variation to test the hypothesis that sugar restriction at young ages counteracts a genetic predisposition for obesity. The researchers compare adult obesity outcomes for individuals conceived before September 1953, who experienced sugar rationing in utero and during early postnatal life, to outcomes for individuals conceived afterwards.

Among individuals genetically predisposed to obesity, sugar rationing in the first year of life reduces the probability of obesity in adulthood by 2.7 percentage points (21 percent).

Using information on 46,914 adults who were born between 1951 and 1956 and contributed data to the UK Biobank between the ages of 52 and 56, the researchers construct a composite index of adiposity. Their index incorporates four normalized measures of body fat: body-mass index, waist-to-hip ratio, body fat percentage, and trunk fat percentage. The researchers identify individuals with index values above the 90th percentile of the never-rationed sample as those with obesity. 

They link their adiposity measure to an index of genetic obesity risk, based on genotypes that predict traits associated with obesity. This genetic index explains 8 percent of the variation in the adiposity index. Within the never-rationed sample, the prevalence of obesity was 4 percent among individuals in the lowest tercile of genetic risk, compared to 16 percent in the top tercile. 

Adults who were exposed to sugar rationing through age 2 had 0.073 standard deviations less adiposity and 3.2 percentage points (32 percent) lower likelihood of obesity. The health benefits of sugar restriction were concentrated among those with a genetic predisposition to obesity. 

Sugar rationing had no impact on the adiposity index or obesity prevalence among adults in the lowest tercile of genetic risk. In contrast, exposure to sugar rationing through age 1 reduced adiposity by 0.082 standard deviations among adults in the two higher-risk terciles, with the magnitude of the effect increasing to 0.117 standard deviations with exposure through age 2. Similarly, higher-risk adults experienced a 2.7 percentage point (21 percent) lower probability of obesity with exposure to sugar rationing through the first year and a 4.5 percentage point (35 percent) lower probability with exposure through age 2. 

Because sugar rationing reduced adiposity and obesity among higher-risk adults without affecting lower-risk adults, it decreased the disparity in outcomes between the two groups. Sustained sugar restriction through age 2 narrowed adiposity gaps between the groups by 22 percent and obesity gaps by 40 percent. 

The researchers acknowledge financial support from the National Institute on Aging of the National Institutes of Health under grants R01AG065482, P30AG012815, P30AG012839, and T32AG000243.

Related

Researchers

Tadeja Gracner
Claire Boone
Patrick Turley
Paul Gertler

Topics

Health, Education, and Welfare
Health

Programs

Economics of Aging
Economics of Health

Articles

A New Approach to Lending in Low- and Middle-Income Countries
How Pro-poor Growth Affects the Demand for Energy
Additional Educational Attainment Reduces Alzheimer’s Risk