People who were restricted to limited amounts of sugar in the first few years of life were less likely to develop diabetes and high blood pressure decades later, a new study has found.

The study, published Thursday in the journal Science, took advantage of a unique situation in the United Kingdom. The country was under strict rationing during World War II and its aftermath. When the rationing ended, in September 1953, the average sugar intake by people in Britain doubled. That provided a natural experiment and allowed the researchers to ask: What happened to the health of people who were conceived and born when sugar was rationed compared with people conceived and born just after sugar rationing ended?

To find out, the researchers, Tadeja Gracner, an economist at the University of Southern California, and her colleagues, Claire Boone of McGill University and Paul J. Gertler of the University of California, Berkeley, turned to the UK Biobank. It contains genetic and medical information on half a million people, and steps have been taken to preserve contributors’ privacy. Using the data, the investigators analyzed the health of 60,183 people who were born from October 1951 through March 1956, and were age 51 to 60 when they were surveyed.

The investigators reported that those exposed to sugar rationing early in life had a 35 percent lower risk of diabetes and a 20 percent lower risk of high blood pressure in middle age. The onset of those chronic diseases was also delayed by four years for diabetes and two years for high blood pressure. They also found that disease protection was greatest for those who had been conceived during sugar rationing and were babies while rationing continued. Those who were exposed to sugar rationing only before birth and then grew up with higher sugar intake had higher disease rates.

The results contribute to a body of evidence suggesting that nutrition very early in life can affect health much later. But because of the unique circumstances of British sugar rationing, the new study provides additional rigor, experts said.

For example, a study of military records of men whose mothers were in the first half of pregnancy during the Dutch famine, or Hunger Winter, during World War II found that the men were more likely to be obese at age 19 than men born after that event. Another study found that women whose mothers were pregnant during the famine were heavier at age 50 than women born later.