Dennis Burkitt documented this in 1973[0][1]. Unfortunately "Don't Forget Fibre in your Diet" (1979) and "F-Plan Diet" (1983) have faded into history a bit.

[0]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1588096/ [1]: https://en.wikipedia.org/wiki/Denis_Parsons_Burkitt