The Medical Research Council (MRC) established the Dunn Nutritional Laboratory in 1927 to research human nutrition and the role of vitamins in human health. The laboratory was named after Sir William Dunn (1833-1912), who had left a substantial donation on his death, and was established with the support of the secretary of the MRC, Sir Walter Fletcher, and Sir Frederick Gowland-Hopkins, Professor of Biochemistry at the University of Cambridge.

In 1998 the Dunn Nutritional Laboratory was restructured into two divisions – the MRC Dunn Nutritional Laboratory and the MRC Human Nutrition Research (HNR). After the division, the Dunn Nutritional Laboratory was under the directorship of Sir John Walker FRS and transferred to the newly constructed Wellcome Trust/MRC Building, shared with the Cambridge Institute for Medical Research. In 2009 the Dunn Laboratory was renamed the Mitochondrial Biology Unit.

MRC HNR was under the directorship of Professor Ann Prentice. In 2001, the unit moved from its original site at Downham's Lane (Milton Road) to a new building at the Peterhouse Technology Park on Fulbourn Road, named the Elsie Widdowson Laboratory. In 2016 the MRC HNR was formally renamed, in honour of the nutritionist Elsie May Widdowson (1906-2000), and was known as MRC EWL. The unit was dissolved in December 2018.