A retrospective and cross-sectional study to evaluate the effect of dietary acculturation on the dietary calcium intake among Filipino women who recently immigrated to New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Human Nutrition at Massey University, Albany, New Zealand

Abstract

Filipinos in New Zealand have steadily grown in number over recent decades, and the majority undergo a dietary acculturation process, or the dietary adaptation of individuals in their host country. In the Philippines, the nutrient with the highest inadequacy in the diet is calcium, primarily contributed by fish and indigenous vegetables that are not readily available in New Zealand. The aim of this study is to determine the effect of dietary acculturation on the calcium intake of Filipino women recently immigrated to New Zealand and to explore the primary factors affecting their bone mineral status. Sixty-two (62) healthy pre-menopausal Filipino women (20–45 years old) were recruited. Current and previous dietary calcium intake, serum 25(OH)D (nmol/L) (n=61), physical activity data via an accelerometer, and bone mineral density (BMD) and body composition through dual-energy X-ray absorptiometry (DXA) were measured. Gross lean mass was calculated (total mass – [whole body total bone content + total fat mass]). Variables considered to be associated with bone mineral status were applied to a multiple regression analysis using the enter method. The median calcium intake for New Zealand [418 (260, 620) mg d-1] after immigration was significantly lower than the intake in the Philippines [506 (358, 823) mg d-1], Z= -2.41, p=0.02, medium effect size r=0.22. The significant predictor of bone mineral status among Filipino women was gross lean mass, whereas current and previous dietary calcium intake, physical activity and serum 25(OH)D were not found to be significant. However, a high prevalence (69%) of serum 25(OH)D <50nmol/L (mild–moderate deficiency) was detected. These findings illustrate the potential detrimental consequences of dietary acculturation on the essential nutrient intake of immigrants, but also provide an opportunity to correct previous dietary inadequacies by exposure to corresponding nutrient-dense foods from the host country.