Alongside her research partner, Dr. Robert McCance (pediatrician, physiologist, biochemist, and nutritionist), they were responsible for overseeing the government-mandated addition of vitamins to food and wartime rationing in Britain during World War II.

Her father eventually owned a stationery business, whilst her mother Rose, originally from Dorking, worked as a dressmaker.

They both attended Sydenham County Grammar School for Girls where there earned prizes and scholarships for their excellence in academia.

For this reason, Widdowson decided to train as a chemist in order to develop skills that offered employment potential.

[3] Widdowson met Robert McCance in the kitchens at King's College Hospital in 1933, when she was studying industrial cooking techniques as part of her diploma on dietetics.

Widdowson and McCance were co-authors of The Chemical Composition of Foods, first published in 1940 by the Medical Research Council (MRC).

Then, they would put themselves on their developed diet of bread, cabbage and potatoes for several months to find out if wartime rationing—with little meat, dairy or calcium intake—would affect their health.

They were consulted on the rehabilitation of the victims of severe starvation in Nazi concentration camps, and visited the Netherlands, Germany and Denmark in early 1946 to study of the impact of the poor wartime diet on the people in Nazi-occupied territories.

She also studied the importance of the nutritional content of infant diets, specifically, vitamins and minerals in natural and artificial human milk.

She was made a member of the Order of the Companions of Honour in 1993, which is awarded for outstanding achievements in the arts, literature, music, science, politics, industry, or religion.

She ate a simple diet, including butter and eggs, and attributed her longevity to good genes: her father lived to 96 and her mother to 107.

[19] As part of the family-friendly policies, Imperial College offers the "Elsie Widdowson Fellowship" for academic staff returning to work following maternity, adoption and/or shared parental leave.

This Fellowship aims to allow academic staff to focus fully on their research after returning to work and not put them at a disadvantage for prioritizing childcare.

[20] In 2009 a Chemical Landmark Plaque was awarded at the Elsie Widdowson Laboratory on Fulbourn Road, Cambridge, former home of MRC Human Nutrition Research.

[21] The Chemical Landmark Plaque is the Royal Society of Chemistry's (RSC) national award recognizing a site of historic significance in science.