with his colleague denis p. burkitt, trowell was influential in promoting dietary fiber. he developed the fiber hypothesis in a series of books and papers with burkitt in the 1970s and 80s. their research showed that diets low in fiber increase the risk of coronary heart disease, diabetes, obesity and large bowel conditions such as colorectal cancer, appendicitis and diverticulosis. the "british medical journal" describes trowell as "probably the first person to link diets deficient in fibre with obesity, diabetes and coronary heart disease."