Although it is generally accepted that intake of sugars should be limited the food industry continues to lobby against governmental strategies to limit intakes claiming the evidence that sugar is harmful is inconsistent and unconvincing. Thus public health researchers must continue to examine the relationship between sugar and disease. However measuring sugar intakes accurately is problematic because people tend to underestimate their consumption and thus the effect of sugars on health in population studies such as the Dunedin Study may be obscured. Recent preliminary US research has shown that carbon stable isotope ratios (δ13C) could be used as an objective measure of sugar intake. We aim to investigate whether this method is valid for the NZ population, which consumes different types of sugars. If δ13C can reliably predict sugar consumption in New Zealanders we will be able to examine the relationship between sugar and disease in the Dunedin Study.