This paper aims to re-examine the dietary practices of individuals buried at Sigatoka Sand Dunes site (Fiji) in Burial Ground 1 excavated by Simon Best in 1987 and 1988 using two approaches and a reassessment of their archaeological, bioarchaeological and chronological frame. First, stable carbon and nitrogen isotope analysis was applied to document dietary changes between childhood and adulthood using an intra–individual approach on paired bone–tooth. Second, the potential adaptation of the individuals to their environment was evaluated through regional and temporal comparisons using inter–individual bone analysis. Ten AMS radiocarbon dates were measured directly on human bone collagen samples, placing the series in a range of approximately 600 years covering the middle of the first millennium CE (1,888 to 1,272 cal BP). δ¹³C and δ¹⁵N ratios were measured on bone and tooth collagen samples from 38 adult individuals. The results show that δ¹⁵N values from tooth are higher than those s from bone while bone and tooth δ¹³C values are similar, except for females. Fifteen individuals were included in an intra–individual analysis based on paired bone and tooth samples, which revealed six dietary patterns distinguished by a differential dietary intake of marine resources and resources at different trophic levels. These highlight sex–specific differences not related to mortuary practices but to daily life activities, supporting the hypothesis of a sexual division of labour. Compared to other Southwest Pacific series, Sigatoka diets show a specific trend towards marine food consumption that supports the hypothesis of a relative food self–sufficiency requiring no interactions with other groups.