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To systematically review the design, implementation and effectiveness of mass media and nutrition education interventions for improving infant and young child feeding (IYCF) practices and related psychosocial factors.
Design
A search of PubMed, Embase and PsycINFO databases, a Google search, and a consultation with experts in the field of IYCF performed in July 2016.
Setting
Low- and middle-income countries, as defined by the World Bank Group.
Subjects
Eligible studies: included a mass media component (with or without nutrition education); conducted a pre–post evaluation (with or without a control group); assessed IYCF knowledge, attitudes, beliefs and/or practices; and were published in English between 2000 and present.
Results
Eighteen unique studies were identified that examined the effect of mass media (types included: television; print; voice and/or SMS (text) messages; radio; megaphones/loudspeakers; videos; social media; songs/dramas) and nutrition education interventions on IYCF practices within thirteen countries. Of these, fifteen studies reported improvements in breast- and/or complementary feeding practices, using indicators recommended by the WHO, and six studies reported improvements in related psychosocial factors. However, little detail was provided on the use of formative research, a formal behaviour change theory and behaviour change techniques. Few studies reported both dose delivered and participants’ exposure to the intervention.
Conclusions
Despite evidence of effectiveness, few common elements in the design of interventions were identified. Future research should consistently report these details to open the ‘black box’ of IYCF interventions, identify effective design components and ensure replicability.
To develop and validate a child and adolescent version of the Three-Factor Eating Questionnaire (CTFEQr17) and to assess its psychometric properties and factor structure. We also examined associations between the CTFEQr17 and BMI and food preferences.
Design
A two-phase approach was utilized, employing both qualitative and quantitative methodologies.
Setting
Primary and secondary schools, UK.
Subjects
In phase 1, seventy-six children (thirty-nine boys; mean age 12·3 (sd 1·4) years) were interviewed to ascertain their understanding of the original TFEQr21 and to develop accessible and understandable items to create the CTFEQr17. In phase 2, 433 children (230 boys; mean age 12·0 (sd 1·7) years) completed the CTFEQr17 and a food preference questionnaire, a sub-sample (n 253; 131 boys) had their height and weight measured, and forty-five children (twenty-three boys) were interviewed to determine their understanding of the CTFEQr17.
Results
The CTFEQr17 showed good internal consistency (Cronbach’s α=0·85) and the three-factor structure was retained: cognitive restraint (CR), uncontrolled eating (UE) and emotional eating (EE). Qualitative data demonstrated a high level of understanding of the questionnaire (95 %). High CR was found to be significantly associated with a higher body weight, BMI and BMI percentile. High UE and EE scores were related to a preference for high-fat savoury and high-fat sweet foods. The relationships between CTFEQr17, anthropometry and food preferences were stronger for girls than boys.
Conclusions
The CTFEQr17 is a psychometrically sound questionnaire for use in children and adolescents, and associated with anthropometric and food preference measures.
Measurement of mean population Na and K intakes typically uses laboratory-based assays, which can add significant logistical burden and costs. A valid field-based measurement method would be a significant advance. In the current study, we used 24 h urine samples to compare estimates of Na, K and Na:K ratio based upon assays done using the field-based Horiba twin meter v. laboratory-based methods.
Design
The performance of the Horiba twin meter was determined by comparing field-based estimates of mean Na and K against those obtained using laboratory-based methods. The reported 95 % limits of agreement of Bland–Altman plots were calculated based on a regression approach for non-uniform differences.
Setting
The 24 h urine samples were collected as part of an ongoing study being done in rural China.
Subjects
One hundred and sixty-six complete 24 h urine samples were qualified for estimating 24 h urinary Na and K excretion.
Results
Mean Na and K excretion were estimated as 170·4 and 37·4 mmol/d, respectively, using the meter-based assays; and 193·4 and 43·8 mmol/d, respectively, using the laboratory-based assays. There was excellent relative reliability (intraclass correlation coefficient) for both Na (0·986) and K (0·986). Bland–Altman plots showed moderate-to-good agreement between the two methods.
Conclusions
Na and K intake estimations were moderately underestimated using assays based upon the Horiba twin meter. Compared with standard laboratory-based methods, the portable device was more practical and convenient.
We have shown that nutrient intakes of rural and urban black Africans in the North West Province (NWP) of South Africa (SA) followed the typical nutrition transition pattern upon urbanization and modernization. The current study aimed to examine and report on the changes in food intakes from 2005 to 2010 in rural and urban black South Africans participating in the PURE-NWP-SA study.
Design/Setting/Subjects
The PURE-NWP-SA study recruited 2010 volunteers aged 35–70 years in 2005, from which detailed food intakes, measured with a validated quantified FFQ, for 1858 participants were available. In 2010, food intakes of a cohort of 1154 of these participants were measured.
Results
Median energy intake increased in men and women in both rural and urban areas from 2005 to 2010. Changes in food intake were interpreted keeping these changes in energy intake and the contribution of foods and food groups to total energy intake in mind. No ‘new’ foods were eaten in 2010, but more participants consumed certain foods and products in 2010 than in 2005. Beneficial changes were increased intakes of vegetables, fruit and milk in most groups. The contribution of cooked staple porridges and bread made from fortified maize and bread flour decreased and therefore also did their contribution to micronutrient intakes.
Conclusions
By promoting and supporting observed beneficial changes such as increased intakes of milk, vegetables and fruit by appropriate policies and educational interventions, it should be possible to steer the nutrition transition in this population into a positive direction.
To compare the contributions of UVB exposure and diet to total vitamin D among Asians living in Kuala Lumpur (KL) and Aberdeen (AB).
Design
Longitudinal study.
Setting
UVB exposure (using polysulfone film badges) and skin colour and dietary vitamin D intake (by web-based questionnaire) were measured at each season in AB and during south-west (SWM) and north-east monsoons (NEM) in KL.
Subjects
One hundred and fifteen Asians in KL and eighty-five Asians in AB aged 20–50 years.
Results
Median summer UVB exposure of Asians in AB (0·25 SED/d) was higher than UVB exposure for the KL participants (SWM=0·20 SED/d, P=0·02; NEM= 0·14 SED/d, P<0·01). UVB exposure was the major source of vitamin D in KL year-round (60%) but only during summer in AB (59%). Median dietary vitamin D intake was higher in AB (3·50 µg/d (140 IU/d)), year-round, than in KL (SWM=2·05 µg/d (82 IU/d); NEM=1·83 µg/d (73 IU/d), P<0·01). Median total vitamin D (UVB plus diet) was higher in AB only during summer (8·45 µg/d (338 IU/d)) compared with KL (SWM=6·03 µg/d (241 IU/d), P=0·04; NEM=5·35 µg/d (214 IU/d), P<0·01), with a comparable intake across the full year (AB=5·75 µg/d (230 IU/d); KL=6·15 µg/d (246 IU/d), P=0·78).
Conclusions
UVB exposure among Asians in their home country is low. For Asians residing at the northerly latitude of Scotland, acquiring vitamin D needs from UVB exposure alone (except in summer) may be challenging due to low ambient UVB in AB (available only from April to October).
To analyse trends in sweetened beverages consumption among adults in Brazil between 2007 and 2016.
Design
A time-series analysis, with data from the Surveillance System of Risk and Protection Factors for Chronic Diseases by Telephone Survey (VIGITEL). The prevalence of regular consumption (≥5 d/week), the average daily consumption (millilitres) and the prevalence of non-consumption of these beverages were analysed. The temporal variations of the indicators were calculated by linear regression. The analyses were performed for the complete set of the evaluated population and stratified by sociodemographic characteristics.
Setting
Brazilian capitals and Federal District.
Subjects
Brazilian adults aged ≥18 years (n 519 641).
Results
There was a reduction in both regular and average daily consumption of sugar- and artificially sweetened beverages (−1·28 percentage points (pp)/year, P=0·001 and −9·63 ml/year, P=0·001, respectively). The same result regarding regular consumption was found when only sugar-sweetened beverages were analysed (−1·11 pp/year, P=0·011). Similar trends were identified in the stratified analyses, with a greater magnitude of reduction among males, young adults, those with higher schooling and residents of more developed regions. Coincidentally, there was an increase in the prevalence of adults who did not consume sweetened beverages (1·54 pp/year, P=0·005).
Conclusions
The consumption of sweetened beverages decreased during the period. However, a significant portion of the population still referred a daily consumption of these beverages.
To study the magnitude and predictors of underweight, incident underweight and recovery from underweight among rural Indian adults.
Design
Prospective cohort study. Each participant’s BMI was measured in 2008 and 2012 and categorized as underweight (BMI<18·5 kg/m2), normal (BMI=18·5–22·9 kg/m2) or overweight/obese (BMI ≥23·0 kg/m2). Incident underweight was defined as a transition from normal weight or overweight/obese in 2008 to underweight in 2012, and recovery from underweight as a transition from underweight in 2008 to normal weight in 2012. Bivariate and multivariable logistic regression analyses were employed.
Setting
The Birbhum Health and Demographic Surveillance System, West Bengal, India.
Subjects
Predominantly rural individuals (n 6732) aged ≥18 years enrolled in 2008 were followed up in 2012.
Results
In 2008, the prevalence of underweight was 46·5 %. From 2008 to 2012, 25·8 % of underweight persons transitioned to normal BMI, 12·9 % of normal-weight persons became underweight and 0·1 % of overweight/obese persons became underweight. Multivariable models reveal that people aged 25–49 years, educated and wealthier people, and non-smokers had lower odds of underweight in 2008 and lower odds of incident underweight. Odds of recovery from underweight were lower among people aged ≥36 years and higher among educated (Grade 6 or higher) individuals.
Conclusions
The current study highlights a high incidence of underweight and important risk factors and modifiable predictors of underweight in rural India, which may inform the design of local nutrition interventions.
To assess household availability of NOVA food groups in nineteen European countries and to analyse the association between availability of ultra-processed foods and prevalence of obesity.
Design
Ecological, cross-sectional study.
Setting
Europe.
Subjects
Estimates of ultra-processed foods calculated from national household budget surveys conducted between 1991 and 2008. Estimates of obesity prevalence obtained from national surveys undertaken near the budget survey time.
Results
Across the nineteen countries, median average household availability amounted to 33·9 % of total purchased dietary energy for unprocessed or minimally processed foods, 20·3 % for processed culinary ingredients, 19·6 % for processed foods and 26·4 % for ultra-processed foods. The average household availability of ultra-processed foods ranged from 10·2 % in Portugal and 13·4 % in Italy to 46·2 % in Germany and 50·4 % in the UK. A significant positive association was found between national household availability of ultra-processed foods and national prevalence of obesity among adults. After adjustment for national income, prevalence of physical inactivity, prevalence of smoking, measured or self-reported prevalence of obesity, and time lag between estimates on household food availability and obesity, each percentage point increase in the household availability of ultra-processed foods resulted in an increase of 0·25 percentage points in obesity prevalence.
Conclusions
The study contributes to a growing literature showing that the consumption of ultra-processed foods is associated with an increased risk of diet-related non-communicable diseases. Its findings reinforce the need for public policies and actions that promote consumption of unprocessed or minimally processed foods and make ultra-processed foods less available and affordable.
To assess the association between food insecurity and depression symptom severity stratified by sex, and test for evidence of effect modification by social network characteristics.
Design
A population-based cross-sectional study. The nine-item Household Food Insecurity Access Scale captured food insecurity. Five name generator questions elicited network ties. A sixteen-item version of the Hopkins Symptom Checklist for Depression captured depression symptom severity. Linear regression was used to estimate the association between food insecurity and depression symptom severity while adjusting for potential confounders and to test for potential network moderators.
Setting
In-home survey interviews in south-western Uganda.
Subjects
All adult residents across eight rural villages; 96 % response rate (n 1669).
Results
Severe food insecurity was associated with greater depression symptom severity (b=0·4, 95 % CI 0·3, 0·5, P<0·001 for women; b=0·3, 95 % CI 0·2, 0·4, P<0·001 for men). There was no evidence of effect modification by social network factors for women. However, for men who are highly embedded within in their village social network, and (separately) for men who have few poor contacts in their personal network, the relationship between severe food insecurity and depression symptoms was stronger than for men on the periphery of their village social network, and for men with many poor personal network contacts, respectively.
Conclusions
In this population-based study from rural Uganda, food insecurity was associated with mental health for both men and women. Future research is needed on networks and food insecurity-related shame in relation to depression symptoms among food-insecure men.
To assess the relative validity of a new, web-based, self-administered 24 h dietary recall, the R24W, for assessment of energy and nutrient intakes among French Canadians.
Design
Each participant completed a 3d food record (FR) and the R24W on three occasions over a 4-week period. Intakes of energy and of twenty-four selected nutrients assessed by both methods were compared.
Setting
Québec City metropolitan area.
Subjects
Fifty-seven women and fifty men (mean (sd) age: 47·2 (13·3) years).
Results
Equivalent proportions of under-reporters were found with the R24W (15·0%) and the FR (23·4%). Mean (sd) energy intake from the R24W was 7·2% higher than that from the FR (10 857 (3184) kJ/d (2595 (761) kcal/d) v. 10 075 (2971) kJ/d (2408 (710) kcal/d); P<0·01). Significant differences in mean nutrient intakes between the R24W and the FR ranged from –54·8% (i.e. lower value with R24W) for niacin to +40·0% (i.e. higher value with R24W) for alcohol. Sex- and energy-adjusted deattenuated correlations between the two methods were significant for all nutrients except Zn (range: 0·35–0·72; P<0·01). Cross-classification demonstrated that 40·0% of participants were classified in the same quartile with both methods, while 40·0% were classified in the adjacent quartile and only 3·6% were grossly misclassified (1st v. 4th quartile). Analysis of Bland–Altman plots revealed proportional bias between the two assessment methods for 8/24 nutrients.
Conclusions
These data suggest that the R24W presents an acceptable relative validity as compared with the FR for estimating usual dietary intakes in a cohort of French Canadians.
The WHO encourages the virtual elimination of artificial trans-fatty acids (TFA), which increase CHD risk. Our UK analysis explores whether voluntary reformulation results in differential TFA intakes among socio-economic groups by determining characteristics of high TFA consumers before and after product reformulation.
Design
Food intake was collected by 7d weighed records pre-reformulation and 4d diaries post-reformulation. Sociodemographic characteristics of TFA consumers above the WHO limit, and of the top 10 % of TFA consumers as a percentage food energy, were compared with those of lower TFA consumers. Multivariate logistic regression determined independent socio-economic predictors of being a top 10 % consumer.
Subjects
UK National Diet and Nutrition Surveys (NDNS) for adults aged 19–64 years pre-reformulation (2000/01; N 1724) and post-reformulation (2010/11–2011/12; N 848).
Results
Post-reformulation 2·5 % of adults exceeded the WHO limit, v. 57 % pre-reformulation. In unadjusted analyses, high TFA consumption was associated with lower income, lower education and long-term illness/disability pre- but not post-reformulation. In adjusted pre-reformulation analyses, degree holders were half as likely as those without qualifications to be top 10 % consumers (OR=0·51; 95 % CI 0·28, 0·92). In adjusted post-reformulation analyses, those with higher income were 2·5–3·3 times more likely to be top 10 % consumers than lowest income households. Pre-reformulation, high consumers consumed more foods containing artificial TFA, whereas ruminant TFA were more prominent post-reformulation.
Conclusions
High TFA consumption was associated with socio-economic disadvantage pre-reformulation, but evidence of this is less clear post-reformulation. Voluntary reformulation appeared effective in reducing TFA content in many UK products with mixed effects on dietary inequalities relating to income and education.
HOT TOPIC: Beverage industry: role, responsibilities, and impacts
To assess the effectiveness of the self-regulatory Canadian Children’s Food and Beverage Advertising Initiative (CAI) in limiting advertising of unhealthy foods and beverages on children’s preferred websites in Canada.
Design/Setting/Subjects
Syndicated Internet advertising exposure data were used to identify the ten most popular websites for children (aged 2–11 years) and determine the frequency of food/beverage banner and pop-up ads on these websites from June 2015 to May 2016. Nutrition information for advertised products was collected and their nutrient content per 100 g was calculated. Nutritional quality of all food/beverage ads was assessed using the Pan American Health Organization (PAHO) and UK Nutrient Profile Models (NPM). Nutritional quality of CAI and non-CAI company ads was compared using χ2 analyses and independent t tests.
Results
About 54 million food/beverage ads were viewed on children’s preferred websites from June 2015 to May 2016. Most (93·4 %) product ads were categorized as excessive in fat, Na or free sugars as per the PAHO NPM and 73·8 % were deemed less healthy according to the UK NPM. CAI-company ads were 2·2 times more likely (OR; 99 % CI) to be excessive in at least one nutrient (2·2; 2·1, 2·2, P<0·001) and 2·5 times more likely to be deemed less healthy (2·5; 2·5, 2·5, P<0·001) than non-CAI ads. On average, CAI-company product ads also contained (mean difference; 99 % CI) more energy (141; 141·1, 141·4 kcal, P<0·001, r=0·55), sugar (18·2; 18·2, 18·2 g, P<0·001, r=0·68) and Na (70·0; 69·7, 70·0 mg, P<0·001, r=0·23) per 100 g serving than non-CAI ads.
Conclusions
The CAI is not limiting unhealthy food and beverage advertising on children’s preferred websites in Canada. Mandatory regulations are needed.
To understand caregivers’ perceptions of children’s linear growth and to identify the cultural meanings and perceptions of risk associated with poor height attainment.
Design
Three investigators from Bangladesh conducted twelve focus group discussions.
Setting
The study was conducted in rural and slum settings in Bangladesh.
Subjects
Participants included mothers and alternative caregivers (n 81) who were recruited by household screening. No eligible, recruited subjects refused participation.
Results
Caregivers reported limited experience with growth monitoring services from the health system. Caregivers mainly use visual cues and developmental milestones to understand if children are growing properly, and recognize that children normally experience both weight gain and linear growth with age. Mothers expressed concern over children’s malnutrition and short stature, but did not discuss children’s failure to attain a ‘growth potential’ or distinguish inherited short stature from stunting. Caregivers interpret the consequences of poor height attainment as primarily social and economic and cite few health risks.
Conclusions
Linear growth interpretation is determined more by community norms than by guidance from nutrition programming or the health system. Interventions to prevent or reduce linear growth failure may be perceived to have limited value where appropriate linear growth in children is determined by comparison to peers and siblings. Such perceptions may be significant barriers to programmes addressing stunting prevention in settings where many children are stunted. Efforts to raise awareness about the risks of linear growth faltering may need to consider delivering messages to caregivers that emphasize the social and economic consequences of stunting.
We aimed to evaluate the association between household food insecurity and maternal depression in Ethiopia.
Design/Setting/Subjects
In 2014, we conducted a cross-sectional study in southern Ethiopia, including 591 food-secure and 2500 food-insecure households. We measured depression status of women using the Patient Health Questionnaire-9 validated for Ethiopia, with a cut-off of ≥5. We evaluated household-level food insecurity using a validated Household Food Insecurity Access Scale. We applied Bayesian modelling to evaluate the relationship between food insecurity and maternal depression accounting for other observed characteristics.
Results
Among the analytic sample, 80·8 (95 % CI 79·4, 82·2) % of women were living in food-insecure households. The overall prevalence of probable depression (mild and moderate forms) was 4·7 (95 % CI 4·1, 5·6) %. All individual depressive symptoms had a significantly higher prevalence in the food-insecure group, except for suicidal ideation (but small numbers; P<0·001). In the Bayesian model adjusting for paternal characteristics, there was a significant dose–response linear relationship (trend) between household food insecurity and maternal depression (P<0·01). The adjusted OR (95 % Bayesian credible interval) for depression for differing levels of food insecurity were: mild food insecurity, 3·29 (1·63, 6·18); moderate, 3·82 (1·91, 7·45); severe, 12·50 (3·38, 32·70).
Conclusions
The study documented a high burden of depression among women who lived in food-insecure households. Given this finding, we recommend integrating mental health in the livelihood programmes in areas suffering from food insecurity.
Mobile phones can replace traditional self-monitoring tools through cell phone-based ecological momentary assessment (CEMA) of lifestyle behaviours and camera phone-based images of meals, i.e. photographic food records (PFR). Adherence to mobile self-monitoring needs to be evaluated in real-world treatment settings. Towards this goal, we examine CEMA and PFR adherence to the use of a mobile app designed to help mothers self-monitor lifestyle behaviours and stress.
Design/Setting
In 2012, forty-two mothers recorded CEMA of diet quality, exercise, sleep, stress and mood four times daily and PFR during meals over 6 months in Los Angeles, California, USA.
Subjects
A purposive sample of mothers from mixed ethnicities.
Results
Adherence to recording CEMA at least once daily was higher compared with recording PFR at least once daily over the study period (74 v. 11 %); adherence to both types of reports decreased over time. Participants who recorded PFR for more than a day (n 31) were more likely to be obese v. normal- to overweight and to have higher blood pressure, on average (all P<0·05). Based on random-effects regression, CEMA and PFR adherence was highest during weekdays (both P<0·01). Additionally, PFR adherence was associated with older age (P=0·04). CEMA adherence was highest in the morning (P<0·01). PFR recordings occurred throughout the day.
Conclusions
Variations in population and temporal characteristics should be considered for mobile assessment schedules. Neither CEMA nor PFR alone is ideal over extended periods.
To determine the prevalence and correlates of healthy vitamin D status in lactating Inuit women living in remote regions of the Arctic.
Design
Cross-sectional.
Setting
Households were selected randomly in thirty-six communities of Nunavut, Nunatsiavut and Inuvialuit Settlement Region. Dietary intake was assessed using a 24 h recall and an FFQ. Anthropometric measurements, household living conditions, supplement use and health status were assessed. In fasting samples, serum 25-hydroxyvitaimn D (25(OH)D) was measured using a chemiluminescent assay (LIAISON; Diasorin Inc.).
Subjects
Lactating Inuit women participating in the 2007–2008 International Polar Year Inuit Health Survey conducted in the months of August to October.
Results
Among participants (n 34), 8·8, 26·5 and 50·0 % had 25(OH)D concentrations at or above 75, 50 and 40 nmol/l, respectively. More than one-third of participants did not consume traditional foods during the previous day and only 11·3 % of total energy intake was derived from traditional foods. Only 14·7 % of the sample consumed the daily number of milk servings recommended by Canada’s Food Guide (two servings) for First Nations, Inuit and Métis. Using multivariable logistic regression to examine 25(OH)D≥40 nmol/l, only higher body fat was inversely correlated with 25(OH)D concentration.
Conclusions
The present study is the first to assess simultaneously vitamin D status and other known factors that affect it among lactating Inuit women living in remote communities in the Arctic. Healthy maternal vitamin D status was observed in 25 % of participants during the late summer and early autumn. This requires further assessment in a larger sample spanning more seasons.
The present study set out to determine whether morning spot urine samples can be used to monitor Na (and K) intake levels in South Africa, instead of the ‘gold standard’ 24 h urine sample.
Design
Participants collected one 24 h and one spot urine sample for Na and K analysis, after which estimations using three different formulas (Kawasaki, Tanaka and INTERSALT) were calculated.
Setting
Between 2013 and 2015, urine samples were collected from different population groups in South Africa.
Subjects
A total of 681 spot and 24 h urine samples were collected from white (n 259), black (n 315) and Indian (n 107) subgroups, mostly women.
Results
The Kawasaki and the Tanaka formulas showed significantly higher (P≤0·001) estimated Na values than the measured 24 h excretion in the whole population (5677·79 and 4235·05 v. 3279·19 mg/d). The INTERSALT formula did not differ from the measured 24 h excretion for the whole population. The Kawasaki formula seemed to overestimate Na excretion in all subgroups tested and also showed the highest degree of bias (−2242 mg/d, 95 % CI−10 659, 6175) compared with the INTERSALT formula, which had the lowest bias (161 mg/d, 95 % CI−4038, 4360).
Conclusions
Estimations of Na excretion by the three formulas should be used with caution when reporting on Na intake levels. More research is needed to validate and develop a specific formula for the South African context with its different population groups. The WHO’s recommendation of using 24 h urine collection until more studies are carried out is still supported.
The present communication demonstrates that even if individuals are answering a pre/post survey at random, the percentage of individuals showing improvement from the pre- to the post-survey can be surprisingly high. Some simple formulas and tables are presented that will allow analysts to quickly determine the expected percentage of individuals showing improvement if participants just answered the survey at random. This benchmark percentage, in turn, defines the appropriate null hypothesis for testing if the actual percentage observed is greater than the expected random answering percentage.
Design
The analysis is demonstrated by testing if actual improvement in a component of the US Department of Agriculture’s (USDA) Expanded Food and Nutrition Education Program is significantly different from random answering improvement.
Setting
USA.
Subjects
From 2011 to 2014, 364320 adults completed a standardized pre- and post-survey administered by the USDA.
Results
For each year, the statement that the actual number of improvements is less than the expected number if the questions were just answered at random cannot be rejected. This does not mean that the pre-/post-test survey instrument is flawed, only that the data are being inappropriately evaluated.
Conclusions
Knowing the percentage of individuals showing improvement on a pre/post survey instrument when questions are randomly answered is an important benchmark number to determine in order to draw valid inferences about nutrition interventions. The results presented here should help analysts in determining this benchmark number for some common survey structures and avoid drawing faulty inferences about the effectiveness of an intervention.