Low-fat intake with falling fiber intake commensurate with rarity of noninfective bowel diseases in blacks in Soweto, Johannesburg, South Africa.

Among urban blacks in Johannesburg, South Africa, a measure of westernization of diet has occurred. Yet, the frequencies of most noninfective bowel diseases not only are low but also appear to have scarcely increased. To assess more adequately the current dietary pattern, a survey was undertaken. Results indicated a habitually low-fat intake, which supplied a mean of 24% of energy but also greatly decreased fiber intake (now about 14 g daily). Possibly, a meaningful rise in the incidence of bowel diseases requires, among other things, simultaneous rise in fat intake; alternatively, there are factors yet unknown in the dietary context of urban blacks (perhaps operating in their bowels) that are inhibiting rises in the diseases mentioned.