To validate an automated food image identification system, DietCam, which has not been validated, in identifying foods with different shapes and complexities from passively taken digital images.

Participants wore Sony SmartEyeglass that automatically took three images per second, while two meals containing four foods, representing regular- (i.e., cookies) and irregular-shaped (i.e., chips) foods and single (i.e., grapes) and complex (i.e., chicken and rice) foods, were consumed. Non-blurry images from the meals’ first 5 min were coded by human raters and compared with DietCam results. Comparisons produced four outcomes: true positive (rater/DietCam reports yes for food), false positive (rater reports no food; DietCam reports food), true negative (rater/DietCam reports no food) or false negative (rater reports food; DietCam reports no food).

Laboratory meal.

Thirty men and women (25·1 ± 6·6 years, 22·7 ± 1·6 kg/m2, 46·7 % White).

Identification accuracy was 81·2 and 79·7 % in meals A and B, respectively (food and non-food images) and 78·7 and 77·5 % in meals A and B, respectively (food images only). For food images only, no effect of food shape or complexity was found. When different types of images, such as 100 % food in the image and on the plate, <100 % food in the image and on the plate and food not on the plate, were analysed separately, images with food on the plate had a slightly higher accuracy.

DietCam shows promise in automated food image identification, and DietCam is most accurate when images show food on the plate.

To assess whether disparities in energy consumption and insufficient energy intake in India have changed over time across socio-economic status (SES).

This cross-sectional, population-based survey study examines the relationship between several SES indicators (i.e. wealth, education, caste, occupation) and energy consumption in India at two time points almost 20 years apart. Household food intake in the last 30 d was assessed in 1993–94 and in 2011–12. Average dietary energy intake per person in the household (e.g. kilocalories) and whether the household consumed less than 80 % of the recommended energy intake (i.e. insufficient energy intake) were calculated. Linear and relative risk regression models were used to estimate the relationship between SES and average energy consumed per day per person and the relative risk of consuming an insufficient amount of energy.

Rural and urban areas across India.

A nationally representative sample of households.

Among rural households, there was a positive association between SES and energy intake across all four SES indicators during both survey years. Similar results were seen for energy insufficiency vis-à-vis recommended energy intake levels. Among urban households, wealth was associated with energy intake and insufficiency at both time points, but there was no educational patterning of energy insufficiency in 2011–12.

Results suggest little overall change in the SES patterning of energy consumption and percentage of households with insufficient energy intake from 1993–94 to 2011–12 in India. Policies in India need to improve energy intake among low-SES households, particularly in rural areas.

Early childhood factors can have persisting effects on development and cognition in children. We propose to explore the trends of Fe deficiency and Pb toxicity in early childhood and their association with child development at 2 years of age and cognition at 5 years.

Longitudinal birth cohort study.

Urban slum, Vellore, India.

Children enrolled at birth were followed up regularly in the first 2 years with developmental and cognitive assessments at 2 and 5 years of age, respectively.

The birth cohort enrolled 251 children with 228 children followed up at 2 years and 212 at 5 years of age. Fe deficiency (ID) was highest at 15 months of age and improved subsequently at 24 months. Blood Pb levels (BLL) remained high at all age groups with an increasing trend with age; 97 % at 36 months having high BLL. Persistent high mean BLL at 15 and 24 months had negative association with both cognition and expressive language raw scores of 24 months, while high mean BLL at 15, 24 and 36 months had no significant association with any of the domains of cognition at 5 years of age. Early childhood cumulative body Fe status at 7, 15 and 24 months did not show any association with child development at 2 years, but was associated with verbal, performance and processing speed components of cognition at 5 years.

Optimising body Fe status and limiting Pb exposure in early childhood can augment child development and school entry cognition.

The aim of the study was to assess the potential association between serum 25-hydroxyvitamin D (25(OH)D) and whole-body bone mineral density (BMD) among 16-year-old adolescents and to study the prevalence of 25(OH)D insufficiency, defined as concentration under 50 nmol/l.

A cross-sectional study.

Reykjavik, Iceland, latitude 64°08′N. Measurements took place in the Icelandic Heart Association's research lab during April–June 2015.

In total, 411 students in Reykjavik, Iceland, were invited to participate, 315 accepted the invitation (76·6 %) and 289 had valid data (mainly Caucasian).

25(OH)D < 50 nmol/l was observed in 70 % of girls and 66·7 % of boys. 25(OH)D ≥ 50 nmol/l was significantly associated with higher whole-body BMD after adjusting for the influence of sex, height, fat mass and lean mass. A linear relationship between 25(OH)D and whole-body BMD was significant for 25(OH)D < 50 nmol/l (n 199, P < 0·05) but NS for 25(OH)D ≥ 50 nmol/l (n 86, P = 0·48).

Our results are in line with some but not all previous studies on the relationship between BMD and 25(OH)D in adolescents. The observed difference in BMD between those with above v. below a 25(OH)D concentration of 50 nmol/l was of about a fifth of one SD, which may have a clinical relevance as one SD decrease in volumetric BMD has been associated with a 89 % increase in 2 years risk of fracture. Icelandic adolescents should be encouraged to increase their vitamin D intake as it is possible that their current intake is insufficient to achieve optimal peak bone mass.

We aimed to assess the validity of maternal recall of exclusive breastfeeding (EBF) at 3 months obtained 12 months after childbirth.

A population-based birth cohort study. The gold standard is maternal report of EBF at the age of 3 months (yes or no) and age of introduction of other foods in the infant’s diet. EBF was considered when the mother reported that no liquid, semi-solid or solid food was introduced up to that moment. The variable to be validated was obtained at 12 months after childbirth when the mother was asked about the age of food introduction. The prevalence of EBF at 3 months, and sensitivity, specificity, positive (PPV) and negative predictive values (NPV), and accuracy of 12-month recall with 95 % CI were calculated.

Pelotas, Brazil.

3700 mothers of participants of the Pelotas 2004 Birth Cohort.

The prevalence of EBF at 3 months was 27·8 % (95 % CI 26·4, 29·3) and 49·0 % (95 % CI 47·4, 50·6) according to gold standard and maternal recall, respectively. The sensitivity of maternal recall at 12 months was 98·3 % (95 % CI 97·4, 99·0), specificity 70·0 % (95 % CI 68·2, 71·7), PPV 55·8 % (95 % CI 53·4, 58·1), NPV 99·1 % (95 % CI 98·6, 99·5) and accuracy 77·9 % (95 % CI 76·6, 79·2). When the analyses were stratified by maternal and infant characteristics, the sensitivity remained around 98 %, and the specificity ranged from 64·4 to 81·8 %.

EBF recalled at the end of the first year of infant’s life is a valid measure to be used in epidemiological investigations.

The present study aimed to evaluate the validity and reproducibility of a thirteen-item FFQ regarding identification of dietary conditions in a rural population in China.

A reproducibility study repeated the first FFQ (FFQ1) approximately 4 weeks later (FFQ2). A validity study evaluated the mean of three consecutive 24 h diet recalls as the reference measure.

Cross-sectional study.

Residents of a rural area in Henan Province, which is located in the central region of China.

A total of 295 individuals participated in the reproducibility study. In addition, 123 people agreed to participate in the validity study. Spearman’s correlation coefficients between the two FFQ ranged from 0·06 (vegetables) to 0·58 (eggs). Spearman’s correlation coefficients between the two methods of collection ranged from 0·01 for cereal to 0·49 for staple foods. The mean of the intraclass correlation coefficients of the two FFQ (FFQ1 v. FFQ2) was 0·19. Bland–Altman analysis indicated good agreement for most food groups across the range of intake for the two studies.

The study demonstrated that our FFQ design could be used as a representative tool to conduct a dietary evaluation of a rural population.

Even though sub-Saharan African women spend millions of person-hours per day fetching water and pounding grain, to date, few studies have rigorously assessed the energy expenditure costs of such domestic activities. As a result, most analyses that consider head-hauling water or hand pounding of grain with a mortar and pestle (pilão use) employ energy expenditure values derived from limited research. The current paper compares estimated energy expenditure values from heart rate monitors v. indirect calorimetry in order to understand some of the limitations with using such monitors to measure domestic activities.

This confirmation study estimates the metabolic equivalent of task (MET) value for head-hauling water and hand-pounding grain using both indirect calorimetry and heart rate monitors under laboratory conditions.

The study was conducted in Nampula, Mozambique.

Forty university students in Nampula city who recurrently engaged in water-fetching activities.

Including all participants, the mean MET value for head hauling 20 litres (20·5 kg, including container) of water (2·7 km/h, 0 % slope) was 4·3 (sd 0·9) and 3·7 (sd 1·2) for pilão use. Estimated energy expenditure predictions from a mixed model were found to correlate with observed energy expenditure (r2 0·68, r 0·82). Re-estimating the model with pilão use data excluded improved the fit substantially (r2 0·83, r 0·91).

The current study finds that heart rate monitors are suitable instruments for providing accurate quantification of energy expenditure for some domestic activities, such as head-hauling water, but are not appropriate for quantifying expenditures of other activities, such as hand-pounding grain.

(i) Describe the development of a multipurpose Cardio-Med survey tool (CMST) comprising a semi-quantitative FFQ designed to measure dietary intake in multicultural patients with or at high risk of CVD and (ii) report pilot evaluation of test–retest reliability and validity of the FFQ in measuring energy and nutrient intakes.

The CMST was developed to identify CVD risk factors and assess diet quality over 1 year using an FFQ. Design of the ninety-three-item FFQ involved developing food portion photographs, and a list of foods appropriate for the Australian multicultural population allowing the capture of adherence to a Mediterranean diet pattern. The FFQ was administered twice, 2 weeks apart to assess test–retest reliability, whilst validity was assessed by comparison of the FFQ with a 3-d food record (3DFR).

The Northern Hospital and St Vincent’s Hospital, Melbourne, Australia.

Thirty-eight participants aged 34–81 years with CVD or at high risk.

Test–retest reliability of the FFQ was good: intraclass correlation coefficient (ICC) ranged from 0·52 (Na) to 0·88 (alcohol) (mean 0·79), with energy and 70 % of measured nutrients being above 0·75. Validity was moderate: ICC ranged from 0·08 (Na) to 0·94 (alcohol) (mean 0·59), with energy and 85 % of measured nutrients being above 0·5. Bland–Altman plots demonstrated good levels of agreement between the FFQ and 3DFR for carbohydrates, protein, alcohol, vitamin D and Na.

The CMST FFQ demonstrated good test–retest reliability and moderate validity for measuring dietary energy and nutrients in a multicultural Australian cardiology population.

To assess the relationship between malnutrition, socioeconomic status (SES) and ethnicity in Chilean adult population.

Nationally representative survey (ENS) conducted in 2016–2017. Sociodemographic information, weight, height and hemoglobin (Hb) were measured (2003 ENS). Excess weight was defined as BMI ≥25 kg/m2. Undernutrition included underweight (BMI <18·5 kg/m2), short stature (height <1·49 m in women and <1·62 m in men) or anaemia (Hb <12 g/l). Education and household income level were used as indicators of SES; ethnicity was self-reported. We applied linear combinations of estimators to compare the prevalence of excess weight and undernutrition by SES and ethnicity.

Chile.

In total, 5082 adults ≥20 years (64 % women) and 1739 women ≥20 years for anaemia analyses.

Overall, >75 % of women and men had excess weight. Low SES women either by income or education had higher excess weight ((82·0 (77·1, 86·1) v. 65·0 (54·8, 74·1)) by income; (85·3 (80·6, 89·0) v. 68·2 (61·6, 74·1) %) by education) and short stature (20–49 years; 31(17·9, 48·2) v. 5·2 (2·2,11·4) by education); obesity was also more frequent among indigenous women (20–49 years; 55·8 (44·4, 66·6) v. 37·2 (32·7, 42·0) %) than non-indigenous women. In men, excess weight did not significantly differ by SES or ethnicity, but short stature concentrated in low SES (20–49 years; 47·6 (24·6, 71·6) v. 4·5 (2·1, 9·5) by education) and indigenous men (21·5 (11·9, 5·5, 11·9) v. 8·2 (5·5, 11·9)) (P < 0·05 for all).

In Chile, malnutrition is disproportionately concentrated among women of low SES and indigenous origin; these inequalities should be considered when implementing prevention policies.

In the past decade, South Africa’s obesity epidemic has increased in both children and adults, and being overweight is becoming the norm. Several contributing factors lead to the normalisation of obesity. One of these is the culturally entrenched likeness of larger body sizes or shapes within a milieu of easily accessible unhealthy food and beverages. This qualitative study advances knowledge about the influence of socio-cultural norms and obesogenic environments on weight under estimation and ‘obesity normalisation’ amongst black South Africans living in an urban setting.

A theory-based qualitative study used focus group discussions (FGDs) with a semi-structured interview guide. FGDs were transcribed verbatim and analysed thematically using a constant comparison method.

Soweto, Johannesburg, South Africa, is a setting which has undergone rapid urbanisation and nutrition transition with ubiquitous availability of processed and fast-foods.

Adults older than 18 years living in Soweto (n 57).

There is a wide misperception about obesity amongst black Africans living in an urban setting in Soweto. Participants who admitted to being fat or overweight did not view themselves as such. This could be attributed to unchanging socio-cultural factors that reinforce the acceptability of bigger bodies and living in obesogenic environment.

Without addressing socio-cultural norms that attribute bigger bodies to beauty and wealth, motivating individuals to address weight gain will prove difficult especially for populations living in obesogenic environments. A multi-faceted strategy is required to address obesity in urban South African settings.

The aim of the current study was to evaluate the accuracy of the new software eAT24 used to assess dietary intake in the National Food, Nutrition and Physical Activity Survey (IAN-AF) against urinary biomarkers: N (nitrogen), K (potassium) and Na (sodium).

We conducted a cross-sectional study. Two non-consecutive 24-h dietary recalls (24-HDR) were applied, and a 24-h urine sample was collected. We examined differences between estimates from dietary and urine measures, Pearson correlation coefficients were calculated and the Bland–Altman plots were drawn. Multiple linear regression was used to evaluate the factors associated with the difference between estimates.

Sub-sample from the Portuguese IAN-AF sampling frame.

Ninety-five adults (men and women) aged 18–84 years.

The estimated intake calculated using the dietary recall data was lower than that estimated from urinary excretion for the three biomarkers studied (protein 94·3 v. 100·4 g/d, K 3212 v. 3416 mg/d and Na 3489 v. 4003 mg/d). Considering 2 d of recall, the deattenuated correlation coefficients were 0·33, 0·64 and 0·26 for protein, K and Na, respectively. For protein, differences between dietary and urinary estimates varied according to BMI (β = −1·96, P = 0·017). The energy intake and 24-h urine volume were significantly associated with the difference between estimates for protein (β = 0·03, P < 0·001 and β = −0·02, P = 0·002, respectively), K (β = 0·71, P < 0·001 and β = −0·42, P = 0·040, respectively) and Na (β = 1·55, P < 0·001 and β = −0·81, P = 0·011, respectively).

The new software eAT24 performed well in estimating protein and K intakes, but lesser so in estimating Na intake, using two non-consecutive 24-HDR.

To deepen understanding of the relationship between food insecurity, acculturation, and diagnosis of CHD and related health outcomes among immigrant adults.

Using cross-sectional, nationally representative data from the National Health Interview Survey 2011 to 2015, we address two research questions. First, what is the relationship of household food insecurity and acculturation with: CHD, angina pectoris, heart attack, self-rated poor health and obesity? Second, what is the association of food insecurity with these health outcomes over years of living in the USA? We estimate multivariate logistic regressions without (question 1) and with (question 2) an interaction term between food insecurity and acculturation for CHD and related health outcomes.

USA.

Low-income immigrant adults.

Food insecurity and acculturation are both associated with diagnosis of CHD and related health outcomes among immigrant adults. Food insecurity and acculturation are associated with the health of female immigrants more than males. Also, the differences by food security status in the probability of having several poor health outcomes (self-rated heath, obesity, women’s angina pectoris) are largest for those in the USA for less than 5 years, decrease for those who have lived in the USA for 5–14 years, and are larger again for those in the USA for 15 or more years.

Recent and long-term food-insecure immigrants are more vulnerable to CHD and related health outcomes than those in the USA for 5–14 years. Further research is needed to understand why.

To evaluate the validity and reproducibility of a 152-item semi-quantitative FFQ (SFFQ) for estimating flavonoid intakes.

Over a 1-year period, participants completed two SFFQ and two weighed 7-d dietary records (7DDR). Flavonoid intakes from the SFFQ were estimated separately using Harvard (SFFQHarvard) and Phenol-Explorer (SFFQPE) food composition databases. 7DDR flavonoid intakes were derived using the Phenol-Explorer database (7DDRPE). Validity was assessed using Spearman’s rank correlation coefficients deattenuated for random measurement error (r s ), and reproducibility was assessed using rank intraclass correlation coefficients.

This validation study included primarily participants from two large observational cohort studies.

Six hundred forty-one men and 724 women.

When compared with two 7DDRPE, the validity of total flavonoid intake assessed by SFFQPE was high for both men and women (r s = 0·77 and r s = 0·74, respectively). The r s for flavonoid subclasses ranged from 0·47 for flavones to 0·78 for anthocyanins in men and from 0·46 for flavonols to 0·77 for anthocyanins in women. We observed similarly moderate (0·4–0·7) to high (≥0·7) validity when using SFFQHarvard estimates, except for flavonesHarvard (r s = 0·25 for men and r s = 0·19 for women). The SFFQ demonstrated high reproducibility for total flavonoid and flavonoid subclass intake estimates when using either food composition database. The intraclass correlation coefficients ranged from 0·69 (flavonolsPE) to 0·80 (proanthocyanidinsPE) in men and from 0·67 (flavonolsPE) to 0·77 (flavan-3-ol monomersHarvard) in women.

SFFQ-derived intakes of total flavonoids and flavonoid subclasses (except for flavones) are valid and reproducible for both men and women.

This study aimed to assess the validity of a portable anthropometer against the gold standard among 2-year-old infants from the 2015 Pelotas (Brazil) Birth Cohort.

Birth cohort study.

A fixed Harpenden® infant anthropometer was considered as the gold standard for measuring infant length due to its greater precision and stability. The portable SANNY® (model ES2000) anthropometer was the instrument to be validated. The acceptable mean difference in length between the anthropometers was 0·5 cm. In order to compare length estimates, the interviewers carried out two length measures for each of the anthropometers (fixed and portable) and for each child. The mean of the two lengths was calculated for each anthropometer, and their difference was calculated.

A subsample of 252 24-month-old members of the 2015 Pelotas (Brazil) birth cohort study.

Children’s mean age was 23·5 months. According to Bland–Altman plot, there were no differences in overall lengths between the portable and the fixed anthropometers, or in lengths according to sex. There was a high overall concordance between the length estimates of the fixed and portable anthropometers (ρ = 0·94; 95 % CI 0·92, 0·95).

The portable anthropometer proved to be accurate to measure the length of 24-month-old infants, being applicable to studies using the same standardised protocol used in the present study.

To identify sex-specific cut-off points for waist circumference (WC) in the definition of metabolic syndrome (MetS) for the Chilean adult population.

MetS was defined as the presence of at least two out of four of the following criteria: TAG ≥1·7 mmol/l; HDL-cholesterol: <1·3 mmol/l in women and <1·0 mmol/l in men; systolic blood pressure ≥130 mmHg and/or diastolic blood pressure ≥85 mmHg; and fasting glucose ≥ 5·6 mmol/l or current treatment for diabetes. The receiver operating characteristics curve and the AUC were computed to derive the specificity and sensitivity using bootstrapping (10 000 iterations restricted to have at least between 40 and 60 % of the original population). The optimal cut-off point for the Chilean population was computed by sex.

A representative sample of the Chilean population aged ≥15 years.

8182 participants (60 % women) from the three available Chilean National Health Surveys conducted in 2003, 2009–2010 and 2016–2017.

WC had a good predictive ability for MetS (AUC for men 0·74 (95 % CI 0·72, 0·76); AUC for women 0·71 (95 % CI 0·68, 0·73)). The optimal cut-off points for WC, in the definition of MetS, were 92·3 cm (95 % CI 90·5, 94·4) and 87·6 cm (95 % CI 85·8, 92·1) for men and women, respectively.

The mentioned cut-off points should be used for WC in the definition of MetS in Chile. As a result, the current recommendation (WHO/International Diabetes Federation) for WC, in the identification of MetS, is not supported by these findings in a representative sample of the Chilean adult population.

The aim of this study was to assess the validity and reliability of a self-administered nutrition knowledge (NK) questionnaire for Italian university students.

The NK questionnaire included ninety questions on experts’ nutritional recommendations, nutritional content of food, health aspects of food and diets, relationship between diet and diseases, and proper food choices. It was administered to the same population under the same conditions on two different occasions with a time interval of 3 weeks between the two administrations.

The survey was carried out at the University of Parma (Italy) during the 2018–2019 academic year.

Data were collected for 132 bachelor and master degree students attending the University of Parma, either attending or not nutrition classes during their studies (19–30 years, 29·5 % males, 57·6 % with an academic nutrition background).

The questionnaire revealed high overall internal consistency reliability (Cronbach’s α > 0·8) and a good temporal stability with high correlation of the total score (r = 0·835, P < 0·001). Moreover, it showed a good ability to discriminate between subjects with potentially different NK.

This NK questionnaire proved to be a reliable, valid and easy-to-use tool for assessing the NK of Italian university students, either with or without nutrition background.

To estimate latent dietary profiles in a community-dwelling sample of older Americans and identify associations between dietary profile membership and individual demographic, socio-economic and health characteristics.

Secondary analysis of the 2012 Health and Retirement Study (HRS) and linked 2013 Health Care and Nutrition Study (HCNS). Latent profile analysis identified mutually exclusive subgroups of dietary intake and bivariate analyses examined associations between dietary profile membership, participant characteristics and nutrient intakes.

USA.

An analytic sample of 3558 adults aged 65 years or older.

Four dietary profiles were identified with 15·5 % of the sample having a ‘Healthy’ diet, 42·0 % consuming a ‘Western’ diet, 29·7 % having a diet consisting of high intake of all food groups and 12·7 % reporting relatively low intake of all food groups. Members of the ‘Healthy’ profile reported the greatest socio-economic resources and health, and members of the ‘Low Intake’ profile had the fewest resources and worst health outcomes. Macronutrient and micronutrient intakes varied across profile although inadequate and excessive intakes of selected nutrients were observed for all profiles.

We identified dietary patterns among older Americans typified by either selective intake of foods or overall quantity of foods consumed, with those described as ‘Low Intake’ reporting the fewest socio-economic resources, greatest risk of food insecurity and the worst health outcomes. Limitations including the presence of measurement error in dietary questionnaires are discussed. The causes and consequences of limited dietary intake among older Americans require further study and can be facilitated by the HRS and HCNS.

To determine if a global mid-upper arm circumference (MUAC) cut-off can be established to classify underweight in adults (men and non-pregnant women).

We conducted an individual participant data meta-analysis (IPDMA) to explore the sensitivity (SENS) and specificity (SPEC) of various MUAC cut-offs for identifying underweight among adults (defined as BMI < 18·5 kg/m2). Measures of diagnostic accuracy were determined every 0·5 cm across MUAC values from 19·0 to 26·5 cm. A bivariate random effects model was used to jointly estimate SENS and SPEC while accounting for heterogeneity between studies. Various subgroup analyses were performed.

Twenty datasets from Africa, South Asia, Southeast Asia, North America and South America were included.

All eligible participants from the original datasets were included.

The total sample size was 13 835. Mean age was 32·6 years and 65 % of participants were female. Mean MUAC was 25·7 cm, and 28 % of all participants had low BMI (<18·5 kg/m2). The area under the receiver operating characteristic curve for the pooled dataset was 0·91 (range across studies 0·61–0·98). Results showed that MUAC cut-offs in the range of ≤23·5 to ≤25·0 cm could serve as an appropriate screening indicator for underweight.

MUAC is highly discriminatory in its ability to distinguish adults with BMI above and below 18·5 kg/m2. This IPDMA is the first step towards determining a global MUAC cut-off for adults. Validation studies are needed to determine whether the proposed MUAC cut-off of 24 cm is associated with poor functional outcomes.