David Barker is a prominent British epidemiologist known for his research on the impact of early life conditions on health. He is best recognized for the Barker Hypothesis, which suggests that poor nutrition and adverse conditions during fetal development can lead to chronic diseases in adulthood. His work has significantly influenced public health policies and understanding of disease prevention. Barker has held various academic positions, including at University College London and the University of Southampton. His research has contributed to the fields of public health and preventive medicine, emphasizing the importance of maternal health and nutrition for future generations.