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THE EFFECT OF PLANT-BASED HOMESTEAD FOOD PRODUCTION WITH AND WITHOUT SMALL-SCALE AQUACULTURE ON DIETARY INTAKE OF WOMEN FARMERS AND THEIR CHILDREN IN PREY VENG, CAMBODIA by Vashti Carmell Verbowski B.Sc., The University of British Columbia, 2009 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Land and Food Systems) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) October 2015 © Vashti Carmell Verbowki, 2015 Abstract In 2011-2013, 15.4% of the Cambodian population was undernourished, compared to <5% in Canada. The Cambodian diet is rice-based and low in nutrient-dense animal-source foods. Homestead food production (HFP) and aquaculture are potential interventions to improve dietary intake. However, we lack comprehensive evidence that these interventions improve intake. Using a cluster randomized control trial, I aimed to determine whether women and children receiving HFP with or without aquaculture have higher intakes or lower prevalence of inadequate intakes of select nutrients, compared to controls in Prey Veng, Cambodia. Ninety villages of ten households each (n=900) were randomized to: HFP, HFP plus aquaculture, or control. After 22-months of intervention, interviewers collected 24-hour dietary recalls (24HRs) from women 18-50 y (n=429) and children 6 m-7 y (n=421). Repeat 24HRs were collected (n=139) to allow for adjustment of within-person variation in intake (using PC-SIDE software). Mean nutrient intakes were compared using generalized estimating equations (GEE) models. Prevalence of nutrient inadequacy was compared by applying the Estimated Average Requirement cut-point method or probability approach and using GEE models. After intervention, women in the HFP group had higher mean intakes of zinc (+1.0 mg) and vitamin A (+139 Retinol Activity Equivalent (RAE)), compared to controls (p<0.05). Women in the HFP plus aquaculture group had higher mean intakes of vitamin A (+191 RAE) and iron (+2.7 mg), and lower prevalence of inadequate vitamin A intake (-19%) and iron intake at 10% bioavailability (-7%) and 5% bioavailability (-2%) levels, compared to controls (p<0.05). Among groups of children and between the HFP and HFP plus aquaculture groups for both women and children, there were no significant differences in nutrient intakes or prevalence of nutrient inadequacy. This research provides evidence that intervention with HFP in Cambodia ii results in higher zinc and vitamin A intakes, and intervention with HFP plus aquaculture results in higher vitamin A and iron intakes and reduced prevalence of inadequate vitamin A and iron intakes among women, compared to controls. Future research should assess the impact of these changes on clinical outcomes, the effect of seasonal changes on intake, and the feeding relationship between women and children. iii Preface This research thesis is my original work and was completed with supervision from Dr. Tim Green and guidance from my committee members, Dr. Judy McLean, Dr. Susan Barr, and Dr. Larry Lynd. My research project is part of the Fish on Farms (FoF) project, which is funded by the International Development Research Centre (IDRC) and the government of Canada, provided through the Department of Foreign Affairs, International Trade, and Development (DFAITD). The FoF project is a collaboration between the Human Nutrition Graduate Program at the University of British Columbia (UBC), Helen Keller International (HKI) in Phnom Penh, Cambodia, Organization to Develop Our Villages (ODOV), Ministry of Agriculture, Forestry and Fisheries (MAFF), World Fish Centre, and the government of Cambodia. The principal investigators of the project are Dr. Tim Green and Dr. Zaman Talukder. Ethics approval was obtained in both Canada and Cambodia, from the UBC Research Ethics Board (approval number H12-00451) and the Cambodian Medial Ethics Board (approval number 010 NECHR). I have received funding to complete my thesis work from the Mary and David Macaree Fellowship, the Faculty of Land and Food Systems Graduate Award, the Indrajit and Manjula Desai Prize in Human Nutrition, and from the Fish on Farms project research fund. My thesis work began after the Fish on Farms project was initiated, and my involvement in the project was concentrated around endline data collection (May 26 – June 10, 2014). Along with the team of staff from HKI Cambodia, I was primarily involved with developing the endline 24-hour dietary recall (24HR) forms and data collection protocols. I trained eight interviewers (recruited by HKI Cambodia) to conduct 24HR interviews and I helped facilitate and supervise endline 24HR data collection. After the data were collected, the staff at HKI Cambodia was responsible for translating 24HRs (from Khmer to English) and I was responsible for analyzing iv the 24HRs from both baseline (collected prior to my involvement in the project) and endline. I maintained a close working relationship with HKI Cambodia staff (namely Sok Hoing Ly and Many Eath) while completing my research in Canada, to clarify discrepancies in the data and obtain local knowledge about Cambodian foods. With assistance from a paid student (Ingrid Chandra) and student volunteer (Mandy Behnia), I entered baseline and endline 24HR data and analyzed the data independently, with guidance from my thesis committee and statisticians, Kathy (Huiqing) Li from the UBC Faculty of Pharmaceutical Sciences and support staff from the UBC Library Research Commons. A research fellow from the University of Otago in New Zealand, Dr. Claire Smith, completed PC-SIDE statistical adjustment of dietary intake data. I have given oral presentations of my research in Edmonton at the International Food Security Dialogue in May 2014 titled, “Overcoming the challenges: analyzing Cambodian 24- hour dietary recalls,” which summarized the challenges I faced when analyzing 24HR data from Cambodia and potential solutions for researchers tackling similar obstacles, and in Vancouver at the UBC Land and Food Systems Graduate Student Conference in March 2015 titled, “An exploration of energy and nutrient intake among rural women farmers in Prey Veng, Cambodia (participants of the Fish on Farms project),” which compared my endline dietary intake results against Canadian dietary intake data. I also presented a poster in Winnipeg at the Canadian Nutrition Society Annual Conference in May 2015, titled “The effect of plant-based homestead food production with and without aquaculture on dietary intake of women farmers in Prey Veng, Cambodia,” which summarized and compared my endline dietary intake results across the intervention and control groups. I also intend to summarize results of this thesis for submission to peer reviewed journals for publication. v Table of Contents Abstract .......................................................................................................................................... ii Preface ........................................................................................................................................... iv Table of Contents ......................................................................................................................... vi List of Tables ..................................................................................................................................x List of Figures .............................................................................................................................. xii List of Abbreviations ................................................................................................................. xiii Acknowledgements ......................................................................................................................xv Introduction ..................................................................................................................1 Background on Cambodia.................................................................................................. 1 Undernutrition among women and children in Cambodia ................................................. 1 Causes of undernutrition: UNICEF conceptual framework ............................................... 4 The Cambodian diet ........................................................................................................... 5 Literature Review.........................................................................................................9 Overview of literature review ............................................................................................ 9 Evidence for an integrative approach ................................................................................ 9 Current research on homestead food production ............................................................. 10 Current research on fish consumption in Cambodia ........................................................ 12 Current dietary assessment research in Cambodia........................................................... 13 Review of the 24-hour dietary recall methodology ......................................................... 15 Strengths and limitations of the 24-hour dietary recall method ....................................... 18 Estimating prevalence of inadequacy .............................................................................. 20 Research questions and thesis hypotheses ......................................................................