Lower diet glycaemic index in African than South Asian men in Trinidad and Tobago

Abstract

In Trinidad and Tobago (T&T), diabetes is over two times more common in South Asian (SA) than African (AF) men, with a smaller difference in women. In the USA, high diet glycaemic index (GI) was associated with increased risk of developing diabetes. In T&T, dietary intake data are unavailable. The objective of this study was to conduct a pilot survey of the dietary habits of 50 AF and 50 SA subjects in order to develop a valid nutrition survey instrument for use in T&T. We hypothesized that diet GI would be lower in AF than SA subjects. We collected 24 h dietary recalls from a sample of adults from T&T (26 AF and 33 SA women, and 17 AF and 25 SA men), excluding subjects of mixed or other ethnic backgrounds and those with diabetes or other chronic disorders. AF women were of similar age, but taller and heavier than SA women. There was no significant difference in diet between AF and SA women. AF men were taller than SA men, but of similar age (34 ± 2 years versus 33 ± 2 years) and body mass index (24.1 ± 0.8 kg/m² versus 23.3 ± 0.9 kg/m², respectively). Intakes of energy, fat, protein, carbohydrate and fibre, and diet glycaemic load did not differ significantly, but AF men had a lower diet GI than SA men (56 ± 1 versus 59 ± 1, P < 0.05). Although not conclusive, these results are consistent with previous data suggesting that diet GI may contribute to the development of type 2 diabetes. The data collected during this survey will be useful in developing a food frequency questionnaire for use in T&T to allow this hypothesis to be tested more rigorously in this population.