Dietary Zinc Intake Assessment in Indonesia

A semi-quantitative FFQ to estimate dietary Zn intake in the Indonesian population was developed, focusing particularly on pregnancy and the period of infancy. In an initial phase, participants filled out an online questionnaire to report their recollection of all foods consumed in the previous 24 h (Q-24 h) to gather information on foods commonly consumed in Indonesia. The food items gathered from the Q-24 h were used in the development of a FFQ to be used to estimate habitual Zn intake over a longer period (LFFQ). As this study focused on Zn intake, food items not captured through the Q-24 h but known to be good sources of Zn were added. The LFFQ comprised 82 food items.
A series of food photographs were produced to enable participants to estimate their usual food portion and were based on the recommendations of a previous study (22 (link)). Each food was presented as four portion sizes comprising 25%, 50%, 100% and 125% of a portion commonly consumed or portion on the package label of commercial products. Portions were measured out using an electrical scale (TANITA digital food scale). The amount of Zn in each food was obtained from USDA Nutrient Database for Standard Reference (United States Department of Agriculture 2013; https://data.nal.usda.gov/dataset/usda-national-nutrient-database-standard-reference-legacy-release), the Indonesian food database Nutrisurvey 2007 (http://www.nutrisurvey.de), or from previous studies (23 (link), 24 (link)). A plate or bowl containing the food was arranged together with a spoon and fork on each side. Food was photographed on a white background using a digital camera with a macro lens (Nikon 3100D) and photographs were printed at a size of 4 cm × 8 cm. In parallel, a shorter version of the FFQ (S-FFQ), which comprised fewer food items (28 items), was developed with the aim of reducing the required time for completion and thus pressure on the interviewer and participant during the clinic visit. To develop the S-FFQ, the number of food items was reduced by focusing on Zn-rich foods, such as red meat, offal, avocado, broccoli, spinach, grouping vegetables with lower Zn content, such as cabbage, carrot and lettuce, into a category of “other vegetables” and excluding items that were found to be rarely or never consumed by this population, such as brown rice, veal and pork. The L-FFQ and S-FFQ were compared with one and other and with a 3-day food record (Q3-d).
Both the L-FFQ and the S-FFQ consisted of five sections, which were: (1) personal information about child and parents, which included name, date of birth, birth weight, parents' educational background and occupation; (2) prenatal and birth history; (3) post-natal history, including feeding in the first six months, weaning age and foods, and consumption of food supplements; (4) retrospective record of foods consumed during pregnancy; (5) retrospective record of foods consumed by the child during infancy (from weaning up to age one year old); and (6) record of foods consumed by the child at the point of sampling. The S-FFQ is included as supplementary information.