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Gina Siapco, DrPH
Associate Professor, School of Public Health
School of Public Health
Publications    Scholarly Journals--Submitted
  • Authors: Gina Segovia-Siapco, Mueni Ndiku, & Joan Sabate

    Title: A Low-Cost Approach to Quantify Estimates of Children's Intake during Dietary Assessment in Rural Eastern Kenya

    Submitted to African Journal of Food, Agriculture, Nutrition, and Development

    ( 6/2011 )

    Accurate quantification of amounts of food consumed is critical to the collection of dietary intake data because dietary assessment information can be used in policymaking and monitoring progress towards nutrition goals. When conducting dietary intake assessments in populations that lack education and familiarity with standard measurements for food intake, respondents have difficulty reporting amounts eaten; consequently, estimation errors increase. The purpose of this study was to determine how a low-cost volumetric method compares with the traditional visual method of estimating food portion sizes when conducting dietary intake assessment. Mothers (n=41) in Machakos District, rural Eastern Kenya provided surrogate dietary recalls for their children under 5 years of age through personal interviews. Traditional visual estimation was compared with volumetric estimation using clear or colored water and an inexpensive plastic graduated cylinder in determining amounts of food consumed. Traditional visual estimation of reported intakes had higher estimates compared to the volumetric method estimates using water and a graduated cylinder. Volumetric method using colored and clear water had good agreement especially for liquid foods (68%-79%) and porridge (44%-76%) and had the strongest correlations for mushy foods (r=0.96) and porridge (r=0.94). Colored water provided a better sense of volume and eased the reporting of portion sizes by those who provide the surrogate recalls.  We conclude that the volumetric method using colored water and a graduated cylinder is a feasible, low-cost, practical approach to quantifying food consumption when conducting dietary surveys in rural communities.

  Scholarly Journals--Published
  • Segovia-Siapco, G., Pribis, P., Messina, M., Oda, K., & Sabaté, J. (2014). Is soy intake related to age at onset of menarche? A cross-sectional study among adolescents with a wide range of soy food consumption. Nutrition J, 13 (1): 54.  DOI: 10.1186/1475-2891-13-54. Open access journal 13:54 http://www.nutritionj.com/content/13/1/54.

    ( 6/2014 )
    Full article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4051381/pdf/1475-2891-13-54.pdf
  • Siapco, G., Singh, P., Haddad, E., & Sabaté, J. (2008). Relative validity of a food frequency questionnaire used to assess food intake during a dietary intervention study. Nutrition & Cancer, 60(5):603–611. DOI: 10.1080/01635580802065294 ( 9/2008 )
    Abstract: To develop a cost-effective alternative for evaluating dietary intake in large-scale intervention trials of cancer and cardiovascular disease outcomes, we designed and validated a semiquantitative food frequency questionnaire (FFQ). We collected 6 to 8 of the 24-hr dietary recalls from 87 adults (ages 30-72 yr) who were randomly assigned to a walnut-supplemented diet or a control diet in a 6-mo dietary intervention trial. Relative validity of a 171-item FFQ in assessing intake of selected foods and the prescribed intervention (intake ≥25 g/day or intake < 2 g of walnuts) was determined using 24-h dietary recalls as the reference. De-attenuated correlations between FFQ and dietary recalls were .82 for walnuts, .80 for fruits, .79 for grains, .77 for vegetables, .63 for water, .44 for sweets, and .36 for dairy/eggs. High within-person variation did not allow de-attenuation for the remaining foods, but uncorrected correlations were high (> .7) for the beverage variables. The FFQ correctly classified 86 out of 87 subjects in the 2 prescribed intervention groups. The FFQ can provide an accurate measure of a food-based intervention (i.e., walnut supplementation) in a trial setting and can also accurately estimate a number of other food groups consumed during the trial.
  • Segovia-Siapco, G. (2007). A study of the health status of Filipino workers in selected Seventh-day Adventist institutions in the Philippines. International Forum, 10(2): 65-91. ( 10/2007 ) Link...
  • Segovia-Siapco, G., Singh, P., Jaceldo-Siegl, K., & Sabaté, J. (2007). Validation of a food frequency questionnaire for measurement of nutrient intake in a dietary intervention study. Public Health Nutr, 10(2): 177-184. doi:10.1017/S1368980007226047 ( 2/2007 ) Link...
    http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=648668 Objective To validate a 171-item semi-quantitative food-frequency questionnaire (FFQ) for measurement of nutrient intake in an intervention trial based on walnut supplementation. Design and setting Free-living adults from Southern California were randomly assigned to either an intervention (walnut-supplemented) or a control diet. The prescribed 6-month intervention was ≥ 28 g of walnuts per day for the walnut-supplemented group and ≤ 2 g of walnuts per day for the control group. Participants provided at least six 24-hour dietary recalls and completed a self-administered FFQ. Subjects Eighty-seven adults aged 30–72 years (48 females, 39 males). Results Our findings from validation (by correlation with six diet recall measures) of the measurement of 32 nutrients by the FFQ are as follows. We found significant positive correlations (corrected for measurement error) between the FFQ and diet recalls for total energy (r = 0.34), total carbohydrate (r = 0.42), vegetable protein (r = 0.43), total fat (r = 0.51), polyunsaturated fat (r = 0.77), total fibre (r = 0.60), linoleic acid (r = 0.78) and α-linolenic acid (r = 0.79) – the last nutrient being an excellent nutrient biomarker of the intervention (walnut supplementation). Significant positive correlations were also found for vitamin C (r = 0.96) and certain minerals (r = 0.46–0.80 for calcium, phosphorus, magnesium, iron and potassium). Uncorrected correlations were also high (r>0.40) for retinol, β-carotene, folate and alcohol. Both diet recalls and FFQ showed a similar significant difference in α-linolenic acid content between the walnut-supplemented and control diets. Conclusions The FFQ demonstrated good relative validity in the estimation intake of some of the major nutrients in a dietary intervention trial and was a particularly valid estimate of an important nutrient biomarker of walnut supplementation.
  • SabatéJ., Cordero-MacIntyre Z., Siapco, G., Torabian S., & Haddad E. (2005). Does walnut consumption lead to weight gain? British J of Clin Nutr, 94: 859-864. ( 9/2005 ) Link...