Validation of triple pass 24-hour dietary recall in Ugandan children by simultaneous weighed food assessment
- Helen Nightingale†1,
- Kevin J. Walsh†1,
- Peter Olupot-Olupot2, 3,
- Charles Engoru4,
- Tonny Ssenyondo3,
- Julius Nteziyaremye3,
- Denis Amorut4,
- Margaret Nakuya4,
- Margaret Arimi4,
- Gary Frost1Email author and
- Kathryn Maitland5, 6Email authorView ORCID ID profile
© The Author(s). 2016
Received: 1 June 2016
Accepted: 11 August 2016
Published: 24 August 2016
Undernutrition remains highly prevalent in African children, highlighting the need for accurately assessing dietary intake. In order to do so, the assessment method must be validated in the target population. A triple pass 24 h dietary recall with volumetric portion size estimation has been described but not previously validated in African children. This study aimed to establish the relative validity of 24-h dietary recalls of daily food consumption in healthy African children living in Mbale and Soroti, eastern Uganda compared to simultaneous weighed food records.
Quantitative assessment of daily food consumption by weighed food records followed by two independent assessments using triple pass 24-h dietary recall on the following day. In conjunction with household measures and standard food sizes, volumes of liquid, dry rice, or play dough were used to aid portion size estimation. Inter-assessor agreement, and agreement with weighed food records was conducted primarily by Bland-Altman analysis and secondly by intraclass correlation coefficients and quartile cross-classification.
Nineteen healthy children aged 6 months to 12 years were included in the study. Bland-Altman analysis showed 24-h recall only marginally under-estimated energy (mean difference of 149 kJ or 2.8 %; limits of agreement −1618 to 1321 kJ), protein (2.9 g or 9.4 %; −12.6 to 6.7 g), and iron (0.43 mg or 8.3 %; −3.1 to 2.3 mg). Quartile cross-classification was correct in 79 % of cases for energy intake, and 89 % for both protein and iron. The intraclass correlation coefficient between the separate dietary recalls for energy was 0.801 (95 % CI, 0.429–0.933), indicating acceptable inter-observer agreement.
Dietary assessment using 24-h dietary recall with volumetric portion size estimation resulted in similar and acceptable estimates of dietary intake compared with weighed food records and thus is considered a valid method for daily dietary intake assessment of children in communities with similar diets. The method will be utilised in a sub-study of a large randomised controlled trial addressing treatment in severe childhood anaemia.
This study was approved by the Mbale Research Ethics committee (Reference: 2013–050). Transfusion and Treatment of severe Anaemia in African Children: a randomized controlled Trial (TRACT) registration: ISRCTN84086586.
KeywordsDietary assessment Validation Children Portion size estimation Uganda Undernutrition
Undernutrition, estimated to affect 100,000,000 children in the developing world, is implicated in approximately 45 % of childhood mortality globally [1, 2] and its reduction has been one of the United Nations Millennium Development Goals since 2000 s . Aside from affecting mortality, poor nutrition in the first 1000 days of life is also associated with impaired cognitive ability, and reduced school and work performance . Nutritional intake is fundamentally important to the health of the child and there is an intimate relationship between nutritional intake, nutritional status and infection. In order to develop and assess nutritional strategies and policies aimed at reducing childhood undernutrition, evaluation and validation of reliable methods of quantifying an individual’s macro- and micronutrient intakes are therefore of critical importance.
Several studies in African countries have used single methods for assessing diet including household consumption surveys , weighed food records , food frequency questionnaires [7, 8], and 24-h dietary recall (24hDR) [5–7, 9] with variable success. Common methodologies, such as food frequency questionnaires and retrospective information on dietary history, are largely qualitative and considered as poor barometers of daily intake due to their imprecision [10–12]. Quantitative methods, measuring individual foods consumed (weighed food records, WFR) are the most precise methods for providing quantitative dietary data . These are, however, time-consuming to conduct that results often in a small sample size, as they have been found to be burdensome and disruptive to the respondents. Interactive dietary recall is a potential substitute for a weighed food record. This has been investigated in Ghanaian children  and in Malawian children  in studies using a single 24hDR the day following independent weighed food assessment. This method of dietary recall could only be considered partially validated in the study groups due to some biases and imprecision. The Ghanaian study reported that averaged 24hDR assessments tended to underestimate energy and nutrient intake compared with WFR, while the Malawian study reported the opposite. The over- and under-estimation of energy and nutrients may be reduced by the modifying the triple pass method for 24hDR, which has been shown to maximise recall accuracy for quantitation [16–18] by including volumetric portion size estimation, but this has yet to be evaluated in African children.
The current pilot study sought to establish the relative validity of an interactive 24hDR method with volumetric portion size estimation, compared to concurrent WFR in children in rural Uganda. The tool is intended for future use to assess the impact of daily dietary intake on outcome for a controlled trial of children hospitalised with severe anaemia (Transfusion and Treatment of severe anaemia in African children: a randomised controlled Trial (TRACT), ISRCTN84086586) .
The study’s aims were first, to establish the relative validity of a 24hDR method compared to a weighed food record in estimating intakes of macro- and selected micro-nutrients in children in rural Uganda. Second, to ensure the recall method is feasible and culturally acceptable in this population.
Dietary data from a weighed food record carried out by an independent researcher in the home of the subject was compared to estimated intakes from 24hDR assessments carried out by two other independent researchers the following day, to assess the relative validity of 24hDR. These researchers (clinicians and nurses) were not aware of the outcome of either the weighed food record or the other dietary recall. We opportunistically recruited 24 well children aged 6 months to 12 years attending Mbale and Soroti Regional Referral Hospitals over a two-week period in May 2014. We excluded infants who were entirely breastfed and children currently unwell. Prospective consent was sought from parents or guardians.
Pre-study training involved role-play simulations of data collection including recall and weighed food interviews with non-study child–parent pairs attending hospital to consolidate clinician and nurse training.
Portion size estimation
Methodology of dietary data collection and portion size estimation
Portion Size Estimation
Weighed food record
24-h dietary recall
Volume of play dougha
Standardised food item sizec
Dietary data collection
Dietary data collection occurred in three stages: weighed food record (WFR) and two dietary recalls (DR) each carried out by a separate member of the research team following published protocols [14, 15]. Each researcher completed only one stage with each child and guardian in the home of the child and were blinded to details recorded by other observers. The details of each stage are summarised in Table 1.
For all measures the specific time frame was from the time the child awoke in the morning to the time they slept at night. Any food taken after this time was not included in either WFR or DR since it was not realistic to expect researchers to remain in participants’ houses overnight.
The triple pass 24-h recall, shown to maximise recall accuracy for quantitation , used the following algorithm. The first pass encourages the respondent (guardian/parent) to freely report all food and drink intake for the prior day uninterrupted; in the second pass the interviewer probes for greater details on the exact time, type and quantity of food or drink taken; in the third and final pass the interviewer reviews all food reported in order, prompting for omissions and clarifying ambiguities. Completion of both DR used the same methodology and the same guardian and child to provide information about inter-assessor reliability and reproducibility. Interviews and assessments were carried out English or local languages to ensure accuracy.
Calculation of estimated requirements
Total daily energy and protein requirements were estimated using the methods recommended by the relevant World Health Organization (WHO), Food and Agriculture Organisation of the United Nations (FAO), United Nations University (UNU) or joint publications [21, 22]. Iron requirements were based on the age and gender specific recommended daily allowances presented by Food and Nutrition Board of the US Institute of Medicine .
Data entry and analysis
Data from WFR, DR1 and DR2 were entered into Dietplan 6 (Forestfield Software Limited), and energy, macro- and micronutrient intakes were automatically computed for most foods using McCance and Widdowstone’s ‘The Composition of Foods (Food Standards Agency)’ . These were supplemented, when recipes or foods were not available, by the Ugandan Food Tables (UFT)  which are derived from the United States Department of Agriculture National Nutrient Database for Standard Reference. For food items, such as milk, meat and flour, where composition may vary geographically, both UFT and The Composition of Foods values were compared, and generally the lower of the two values used. Some foods such as oil, and maize and wheat flours are fortified in Uganda with vitamin A, and iron respectively, however this does not appear to be consistent . Since the current study is concerned with method validation only and as such, unfortified values have been used.
We could find no data of direct nutrient analysis of food in Uganda or East Africa therefore some uncertainty remains regarding the accuracy of food composition data in this setting. It is recognised that neither US based UFT values , nor the UK Composition of Foods  may reflect actual nutrient composition of Ugandan foods.
Weight-for-age z-scores (WAZ) were calculated with WHO Anthro using the WHO reference population  and compared to the Uganda Demographic and Health Survey (UDHS), which use the median of the National Centre for Health Statistics , Centres for Disease Control and Prevention (CDC) , and WHO reference populations . All other statistical analysis was completed using IBM SPSS Statistics for Windows v22 (IBM). Prior to statistical tests, Kolmogorov-Smirnov statistic and Q-Q plots were used to assess data distribution. Only estimated energy requirements were non-normally distributed, therefore Wilcoxon signed-rank test was used when comparing estimated energy requirements and estimated intakes and variability was assessed using interquartile range (IQR, 25-75th centiles). Bland-Altman analysis was conducted for a range of macro- and micronutrients, to compare each individual assessment of 24hDR (DR1 and DR2) and then to compare these with WFR . Mean difference and standard deviation of the difference between each DR, and DR and reference method were generated for energy, protein and iron consumption, and reported as mean difference and limits of agreement (i.e. ± 1.96*standard deviation of mean difference).
The relationship between estimated intakes of energy, protein and iron were explored using intraclass correlation coefficients (ICC) and by quartile cross-classification. ICCs compared absolute agreement of average measures, using a two-way random model. Classification was defined as correct (same quartile), adjacent (±1 quartile), or grossly misclassified by 2 or more quartiles. Differences between estimated requirements and estimated intakes by WFR, DR1, and DR2 were analysed using paired t-tests. Initial analysis was completed between WFR, DR1 and DR2 in pairs. Statistical significance was defined as p < 0.05.
Demographics and anthropometry
Of 24 children recruited (14 in Mbale and 10 in Soroti), two did not complete the dietary assessment and three were excluded due to recurring or new illness. Of the remaining 19, 12 were female (61.9 %), mean age (±SD) was 3.4 years (±2.6), and mean weight (±SD) was 14.0 kg (±5.6). The mean WAZ score (±SD) was −0.19 (±1.75). Three children were moderately or severely underweight defined as WAZ scores ≤ −2.0. The majority (n = 13) had WAZ scores between −2 and 2. Three children had high WAZ scores ≥2. Four children were partially breastfed therefore were not included in comparisons with estimated requirements as determining a reliable ‘portion size’ was impossible. A post hoc power analysis showed that with 19 participants, this study has 80 % power to detect a difference of 16.7 % or 1097 kJ in energy intake at a significance level of 0.05, using the mean energy consumption of 6563 kJ and SD of 1706 kJ.
Comparability of WFR and 24-h dietary recall methods
Intraclass and bivariate correlation coefficients comparing estimated intakes by weighed food records and 24-h dietary recallsa
Weighed Food Record
Combined Dietary Recalls
ICC (95 % CI)
Cross-classification of children to quartiles according to intake estimates
Classified correctly (%)
Classified adjacently (%)
Grossly misclassified (by ≥2 quartiles) (%)
Cohen’s Kappa k (p-value)
Estimated requirements and intake
The median estimated requirement for energy was 4602 kJ/day (IQR 25-75th centile = 3836–5208 kJ), and intake was estimated at 6544 kJ (IQR 25-75th centile = 5330–7448 kJ) by the WFR, showing a significant surplus of 1942 kJ (p = 0.001). Mean estimated protein requirement was 14.2 g (±5.1), while WFR-estimated intake was 40.0 g (±12.9)/day, 26.8 g in excess of requirements (p < 0.001). Mean iron requirement was 8.3 mg (±1.6)/day, while WFR-estimated intake was 6.6 mg (±2.6) (p = 0.004).
The 24-h multi-pass recall method described compared favourably to a weighed food records, with regards to energy, protein and iron intakes. Bland-Altman analyses showed overall agreement for energy, protein and iron intakes between two separate interviewers, suggesting high inter-assessor reproducibility, which is further reinforced by high intraclass correlation coefficients. Classification of energy intake into quartiles showed substantial agreement for energy and almost perfect agreement for protein and iron intakes.
High intraclass correlation coefficients, and low mean differences for energy, protein and iron with weighed food records suggest the triple-pass 24 h recalls are comparable for assessing daily intakes. The method suggested by Gibson & Ferguson  was adapted to the local setting and validated in this pilot. Using play-dough and volume displacement generally worked well, and was intuitive for both researchers and subjects. The estimated nutrient intakes must be interpreted with caution owing to wide limits of agreement; in the case of iron particularly, only gross differences in intake can be inferred. For iron one extreme outlier was noted with 4.99 mg lower estimated intake by recalls compared to WFR. The cause of this large discrepancy was found to be due to inaccuracy in the portion size estimation of a ready-to-use nutrient-dense nutritional supplement, which contributed over 6 mg of iron alone to intake, the only instance in this pilot where this supplement was noted. Studies involving severely malnourished children are likely to encounter ready-to-use feed or calorie enhanced milks, and particular care in estimating the portion size is advised due to nutrient density, for the future study (TRACT), where it is intended to be used the numbers of children with severe malnutrition are anticipated to be few.
Although inter-assessor variability was assessed, this study did not address intra-observer repeatability, which must be borne in mind when the method is used. One limitation of only assessing the preceding 24-h period is that a habitual identical intake cannot be assumed. Both dietary recalls were undertaken on the same day, which may have introduced bias in parental recall, for example memory of information provided during the first recall may have been reinforced for the second recall, whether accurate or not, thus artificially reducing the inter-assessor variability. Noteworthy, is that whilst the results presented using the mean of two 24-h dietary recalls will technically reduce the observed variability, the inter-assessor variability was low, therefore conducting a single recall should not have a substantive effect.
Although method validation was the main aim of this study, it is prudent to comment on the intakes observed. Energy intake was higher than in previous reported studies, at 6563 kJ compared to 5606 kJ . Intakes of energy and protein were also in excess of requirements by a factor of 1.39 for energy and 2.97 for protein. Similar high protein intakes of 41.0 g/day have been reported in children in other regions of Uganda . Another potential reason for the difference is variation over the week in energy consumption, which is not reflected on a single day recall assessment. Two reasons are suggested for this observation. Firstly, although it was explained to participants that the priority was to observe the children’s intake unbiased, the effect of the researchers’ presence is difficult to estimate. Secondly, while these were healthy children, all had had recent contact with healthcare services, and as such may be experiencing catch-up growth and provided with additional food for recuperation. Indeed, WAZ scores observed showed that 16 % were severely or moderately underweight, and is similar to the most recent UDHS 2011 census for the Eastern Uganda region , where prevalence was 15.4 %. In contrast to the UDHS results which showed only 0.1 % had WAZ scores >2, compared to 15.8 % (n = 3) of subjects in this pilot.
The methods we have described and validated in children in Uganda appear consistent and correlate satisfactorily with quantitative assessment of dietary intake. A study comparing a single pass 24DR to assess dietary intake with a subsequent 7-day weighed food record in Sri Lankan adults found that 24DR tended to underestimate mean energy levels and macronutrients however the difference in the energy percentages were not statistically different . Underestimation using single pass 24DR has been previously reported and is improved by triple-pass 24DR [17, 18]. We consider that the method we have assessed to be valid for an on going a factorial treatment trial of African children presenting to hospital with severe anaemia (TRACT trial) . The method will be used to assess nutritional intake as a surrogate marker of general wellbeing and the association of acute nutritional intake with severity of anaemia, impaired gut barrier function and susceptibility to infection. The TRACT study combines sequential dietary intake assessment using the multi-pass method at each follow-up visit to estimate macro and micro nutrient intake and will be subsequently linked to biomarkers of gut barrier function, gut microbiome, immunity and hormonal appetite control.
24 h dietary recall
Centres for disease control and prevention
Food and agricultural organisation of the united nations
Intraclass correlation coefficient
Level of agreement
Transfusion and treatment of severe anaemia in African children: a randomised controlled trial
Ugandan demographic and health survey
Ugandan food tables
United nations university
Weighed food record
World health organisation
This research was funded by a grant (MR/J012483/1) from the Medical Research Council, United Kingdom (provided through the MRC DFID concordat). The MRC was not involved in the study design, collection, analysis, interpretation, or manuscript preparation.
Availability of data and materials
The dataset supporting the conclusions of this article is included within the article and its additional files.
HN, GF, KM, POO, and CE designed and planned the study. HN, TS, JN, CM, MN, MA, DA developed the method and carried out data collection. KJW analysed and interpreted the data. HN and KJW drafted the manuscript, and all authors commented on the manuscript. All authors read and approved the final manuscript.
The authors declare that they have no competing interests.
Consent for publication of individual data
Ethics approval and consent to participate
This study was approved by the Mbale Research Ethics committee (Reference: 2013–050). Verbal consent was sought from parents or guardians for researchers to measure the child’s weight, observe and weigh the child’s food intake over 1 day, and for two separate 24 h dietary recalls to be undertaken the following day. The child’s assent and ongoing verbal parental/guardian consent was also sought prior to each activity.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
- Black RE, Victora CG, Walker SP, et al. Maternal and child undernutrition and overweight in low-income and middle-income countries. Lancet. 2013;382(9890):427–51.View ArticlePubMedGoogle Scholar
- Black RE, Allen LH, Bhutta ZA, et al. Maternal and child undernutrition: global and regional exposures and health consequences. Lancet. 2008;371(9608):243–60.View ArticlePubMedGoogle Scholar
- The Millennium Development Goals. New York: United Nations, 2010. http://www.un.org/millenniumgoals/bkgd.shtml.
- Improving Child Nutrition. The achievable imperative for global progress. New York: United Nations Children’s Fund (UNICEF); 2011.Google Scholar
- Jariseta ZR, Dary O, Fiedler JL, et al. Comparison of estimates of the nutrient density of the diet of women and children in Uganda by Household Consumption and Expenditures Surveys (HCES) and 24-h recall. Food Nutr Bull. 2012;33(3 Suppl):S199–207.View ArticlePubMedGoogle Scholar
- Kigutha HN. Assessment of dietary intake in rural communities in Africa: experiences in Kenya. Am J Clin Nutr. 1997;65(4 Suppl):1168S–72S.PubMedGoogle Scholar
- Amare B, Moges B, Moges F, et al. Nutritional status and dietary intake of urban residents in Gondar, Northwest Ethiopia. BMC Public Health. 2012;12:752.View ArticlePubMedPubMed CentralGoogle Scholar
- Lin CA, Boslaugh S, Ciliberto HM, et al. A prospective assessment of food and nutrient intake in a population of Malawian children at risk for kwashiorkor. J Pediatr Gastroenterol Nutr. 2007;44(4):487–93.View ArticlePubMedGoogle Scholar
- Alemayehu AA, Abebe Y, Gibson RS. A 24-h recall does not provide a valid estimate of absolute nutrient intakes for rural women in southern Ethiopia. Nutrition. 2011;27(9):919–24.View ArticlePubMedGoogle Scholar
- Block G, Thompson FE, Hartman AM, et al. Comparison of two dietary questionnaires validated against multiple dietary records collected during a 1-year period. J Am Diet Assoc. 1992;92(6):686–93.PubMedGoogle Scholar
- Block G, Woods M, Potosky A, et al. Validation of a self-administered diet history questionnaire using multiple diet records. J Clin Epidemiol. 1990;43(12):1327–35.View ArticlePubMedGoogle Scholar
- Kipnis V, Subar AF, Midthune D, et al. Structure of dietary measurement error: results of the OPEN biomarker study. Am J Epidemiol. 2003;158(1):14–21. discussion 22–6.View ArticlePubMedGoogle Scholar
- Ferguson EL, Gadowsky SL, Huddle JM, et al. An interactive 24-h recall technique for assessing the adequacy of trace mineral intakes of rural Malawian women; its advantages and limitations. Eur J Clin Nutr. 1995;49(8):565–78.PubMedGoogle Scholar
- Ferguson EL, Gibson RS, Opare-Obisaw C. The relative validity of the repeated 24 h recall for estimating energy and selected nutrient intakes of rural Ghanaian children. Eur J Clin Nutr. 1994;48(4):241–52.PubMedGoogle Scholar
- Thakwalakwa CM, Kuusipalo HM, Maleta KM, et al. The validity of a structured interactive 24-h recall in estimating energy and nutrient intakes in 15-month-old rural Malawian children. Matern Child Nutr. 2012;8(3):380–9.View ArticlePubMedGoogle Scholar
- Gibson R, Ferguson E. An interactive 24-h recall for assessing the adequacy of iron and zinc intakes in developing countries. Washington: International Food Policy Research Institute (IFPRI) and International Centre for Tropical Agriculture (CIAT); 2008.Google Scholar
- Bingham SA, Cassidy A, Cole TJ, et al. Validation of weighed records and other methods of dietary assessment using the 24 h urine nitrogen technique and other biological markers. Br J Nutr. 1995;73(4):531–50.View ArticlePubMedGoogle Scholar
- Ma Y, Olendzki BC, Pagoto SL, et al. Number of 24-h diet recalls needed to estimate energy intake. Ann Epidemiol. 2009;19(8):553–9.View ArticlePubMedPubMed CentralGoogle Scholar
- Mpoya A, Kiguli S, Olupot-Olupot P, et al. Transfusion and Treatment of severe anaemia in African children (TRACT): a study protocol for a randomised controlled trial. Trials. 2015;16(1):593.View ArticlePubMedPubMed CentralGoogle Scholar
- Nutrition Country Profile: The Republic of Uganda. Food and Agricultural Organization of the United Nations, 2010. Available at: http://www.fao.org/docrep/017/aq011e/aq011e.pdf.
- Joint WHO/FAO/UNU Expert Consultation. Protein and amino acid requirements in human nutrition. World Health Organ Tech Rep Ser. 2007;935:1–265.Google Scholar
- Human energy requirements: report of a Joint FAO/WHO/UNU Expert Consultation Rome, 17–24 October 2001. Food Nutr Bull. 2005;26(1):166. (http://www.fao.org/3/a-y5686e.pdf).
- Food and Nutrition Board. Institute of Medicine. Dietary reference intakes for vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc: a report of the panel on micronutrients. Washington DC: National Academy Press; 2001.Google Scholar
- MacCanc RA, Widdowson EM. Food Standards Agency. McCance and Widdowson’s The Composition of Foods. Seventh Summary Edition. Cambridge: The Royal Society of Chemistry, 2015.
- Hotz C, Abdelrahman L, Sison C, et al. A food composition table for central and eastern Uganda. Washington DC: HarvestPlus; 2011.Google Scholar
- Quality of Fortified Foods, Ministry Of Health Food Fortificatin Program, National Monitoring Report. 2007-2008. http://www.ffinetwork.org/monitor/Documents/Uganda.pdf Accessed 21 Aug 2016.
- WHO Child Growth Standards. Growth velocity based on weight, length and head circumference. Methods and development. Geneva: World Health Organization, 2009. Available at: http://www.who.int/childgrowth/publications. Accessed 14 Dec 2014.
- National Center for Health Statistics. Growth curves for children birth to 18 years: United States Department of Health Education and Welfare, Vital and Health Statistics. 1977: Series 11.
- Kuczmarski RJ, Ogden CL, Guo SS, et al. 2000 CDC growth charts for the United States: Methods and development. National Center for Health Statistics. Vital Health Stat 2002;11(246). ISBN 0-8406-0575-7.
- Bland JM, Altman DG. Measuring agreement in method comparison studies. Stat Methods Med Res. 1999;8(2):135–60.View ArticlePubMedGoogle Scholar
- McHugh ML. Inter-rater reliability: the kappa statistic. Biochem Med. 2012;22(3):276–82.View ArticleGoogle Scholar
- Bridge A, Kipp W, Raine K, et al. Nutritional status and food consumption patterns of young children living in Western Uganda. East Afr Med J. 2006;83(11):619–25.PubMedGoogle Scholar
- Uganda Bureau of Statistics (UBOS) and ICF International Inc. 2012. Uganda Demographic and Health Survey 2011. Kampala, Uganda: UBOS and Calverton, Maryland: ICF International Inc. 141–145. (https://dhsprogram.com/pubs/pdf/FR264/FR264.pdf).
- Jayawardena R. Comparison dietary assessment methods in Sri Lankan adults: use of 24-h dietary recall and 7-day weighed intake. BMC Nutrition 2016;2(1).