Data about vitamin B12 (B12) deficiency in the general population are scarce. The present study was performed to determine the prevalence of B12 deficiency in the general population of the Principality of Liechtenstein, as well as to identify sub-populations potentially at high risk.

Retrospective study.

Ambulatory setting, population of the Principality of Liechtenstein.

Seven thousand four hundred and twenty-four patients seeking medical attention whose serum samples were referred for routine work-up in an ambulatory setting were consecutively enrolled. Serum total B12 was determined in all patients in this cohort. In addition, for a subgroup of 1328 patients, serum holotranscobalamin was also measured. Prevalence of B12 deficiency was calculated. Further, multivariate logistical regression models were applied to identify covariates independently associated with B12 deficiency and depletion.

Nearly 8 % of the general population was suffering from either B12 depletion or deficiency. The ratio between B12 depletion and deficiency was 2:1 for all age ranges. Pathological changes were detected predominantly in older people. Female gender was a significant predictor of B12 depletion. In the cohort, nearly 40 % exhibited either depletion or deficiency of B12.

B12 depletion and deficiency are common in Liechtenstein, a Central European country. The measurement of biochemical markers represents a cost-efficient and valid assessment of the B12 state. When a deficiency of B12 is diagnosed at an early stage, many cases can be treated or prevented, with beneficial effects on individual outcomes and subsequent potential reductions in health-care costs.

Lycopene is a potent antioxidant, and it has been suggested that intake of tomatoes and tomato products containing lycopene is associated with a decreased risk of various chronic diseases. The aim of the present study was to evaluate the distribution of dietary lycopene intake in the Belgian population and to determine the most important contributors to lycopene intake.

Cross-sectional study.

National food consumption data from the Belgian Food Consumption Survey (BFCS) 2004 were used for the intake assessment. Determination of the lycopene content in foods was performed with HPLC-UV. Individual food consumption data were multiplied by the actual mean concentrations of lycopene per food.

Individuals (n 3083) aged 15 years and older participated in the study and provided two 24 h recalls.

The mean lycopene intake among Belgian adults was 4·1 (sd 2·3) mg/d or 0·059 (sd 0·033) mg/kg body weight per d. Lycopene intake among men (4·6 (sd 2·6) mg/d) was higher than among women (3·6 (sd 2·1) mg/d), and was higher in the younger compared with the older age groups. Cis-lycopene intake represented about one-third of the total lycopene intake. Tomatoes and tomato products (43 %) and sauces and ready-to-eat meals containing tomato sauces (41 %) were the main contributors to lycopene intake in Belgium.

The lycopene intake of the Belgian adult population was comparable to intakes reported in neighbouring countries and was below the acceptable daily intake.

To examine whether the recent increasing prevalence of obesity was accompanied by variations in energy and macronutrient intakes by weight status.

Time series of cross-sectional surveys.

National Health and Nutrition Examination Surveys (NHANES) in the USA.

Adult participants of NHANES I (1971–1974), II (1976–1980), III (1988–1994) and continuous (1999–2004).

Daily energy intake increased over time for men (9832 to 11 652 kJ, P < 0·01) and women (6418 to 8142 kJ, P < 0·01) in all BMI classes. Percentage of energy intake from carbohydrate increased over time (men: 42·7 % to 48·0 %, P < 0·01; women: 45·4 % to 50·6 %, P < 0·01), whereas percentage of energy intake from fat (men: 36·7 % to 33·1 %, P < 0·01; women: 36·1 % to 33·8 %, P < 0·01) and protein (men: 16·4 % to 15·1 %, P < 0·01; women: 16·9 % to 14·7 %, P < 0·01) decreased. With surveys combined, daily energy intake varied among BMI classes for women (underweight/normal weight: 7460 kJ; overweight: 6799 kJ; obese I: 7033 kJ; obese II/III: 7401 kJ; P < 0·01) but not men. Percentage of energy intake from carbohydrate decreased with increasing BMI class (men: 46·6 % to 45·5 %, P < 0·01; women: 49·0 % to 48·6 %, P < 0·01) whereas percentage of energy intake from fat (men: 34·3 % to 36·5 %, P < 0·01; women: 34·4 % to 35·4 %, P < 0·01) and protein (men: 15·3 % to 16·5 %, P < 0·01; women: 15·2 % to 16·0 %, P < 0·01) increased. Interactions of survey period and BMI class were not statistically significant.

Time trends in energy and macronutrient intakes were similar across BMI classes. Research examining how individuals respond differently to varying dietary compositions may provide greater insight about contributors to the rise in obesity.

To compare, specifically by age group, proxy-reported food group estimates obtained from the food frequency section of the Children's Eating Habits questionnaire (CEHQ-FFQ) against the estimates of two non-consecutive 24 h dietary recalls (24-HDR).

Estimates of food group intakes assessed via the forty-three-food-group CEHQ-FFQ were compared with those obtained by a computerized 24-HDR. Agreement on frequencies of intakes (equal to the number of portions per recall period) between the two instruments was examined using crude and de-attenuated Pearson's correlation coefficients, cross-classification analyses, weighted kappa statistics (κw) and Bland–Altman analysis.

Kindergartens/schools from eight European countries participating in the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) Study cross-sectional survey (2007–2008).

Children aged 2–9 years (n 2508, 50·4 % boys).

The CEHQ-FFQ provided higher intake estimates for most of the food groups than the 24-HDR. De-attenuated Pearson correlation coefficients ranged from 0·01 (sweetened fruit) to 0·48 (sweetened milk) in children aged 2–<6 years (mean = 0·25) and from 0·01 (milled cereal) to 0·44 (water) in children aged 6–9 years (mean = 0·23). An average of 32 % and 31 % of food group intakes were assigned to the same quartile in younger and older children, respectively, and classification into extreme opposite quartiles was ≤12 % for all food groups in both age groups. Mean κw was 0·20 for 2–<6-year-olds and 0·17 for 6–9-year-olds.

The strength of association estimates assessed by the CEHQ-FFQ and the 24-HDR varied by food group and by age group. Observed level of agreement and CEHQ-FFQ ability to rank children according to intakes of food groups were considered to be low.

Adequate assessment of energy balance-related behaviours in adolescents is essential to develop and evaluate effective obesity prevention programmes. The present study examined the test–retest reliability and construct validity of a questionnaire assessing energy balance-related behaviours in adolescents during the evaluation of the DOiT (Dutch Obesity Intervention in Teenagers) intervention.

To assess test–retest reliability, adolescents filled in the questionnaire twice (n 111). To assess construct validity, the results from the first test were compared with data collected in a personal cognitive interview (n 20, independent from the reliability study). For both reliability and validity, intraclass correlation coefficients for continuous data or Cohen's kappa coefficients for categorical data were calculated as well as percentage agreement.

Data were collected during school time from February to May 2010.

Study participants were Dutch adolescents aged 12–14 years attending pre-vocational secondary schools.

In more than three-quarters of the ninety-five questionnaire items the test–retest reliability appeared to be good to excellent. Moderate reliability was found for all other twenty-one items. Fifty-one items (of ninety-five items) showed good to excellent construct validity. Construct validity appeared moderate in twenty-three items and poor in twenty-one items. Most items with poor construct validity concerned consumption of sugar-containing beverages and high-energy snacks/sweets.

Our study showed good test–retest reliability and largely moderate to good construct validity for the majority of items of the DOiT questionnaire. Items with poor construct validity (most of them found for items concerning energy intake-related behaviours) should be revised and tested again to improve the questionnaire for future use.

To evaluate the reliability and relative validity of a semi-quantitative FFQ for assessing the habitual intake of multiple nutrients in New Zealand (NZ) adults over the past 12 months.

A 154-item FFQ was developed. After initial pre-testing, reliability was assessed using intra-class correlations. Relative validity was assessed by comparing nutrient intakes derived from the FFQ v. those from an 8 d diet record (8dWDR) collected over 12 months and selected blood biomarkers, using Spearman correlations. Supplementary cross-classification and Bland–Altman analyses were performed to assess validity of the FFQ v. the 8dWDR.

Dunedin, NZ.

One hundred and thirty-two males and females aged 30–59 years who completed all FFQ and 8dWDR and provided a blood sample.

Reliability coefficients ranged from 0·47 for Ca to 0·83 for alcohol, with most values falling between 0·60 and 0·80. The highest validity coefficients for energy-adjusted data were observed for alcohol (0·74), cholesterol (0·65) and β-carotene (0·58), and the lowest for Zn (0·24) and Ca (0·28). For all energy-adjusted nutrients mean percentage correct classification was 77·9 % and gross misclassification was 4·5 %. Results of Bland–Altman analyses showed wide limits of agreement for all micronutrients but high agreement was observed for most macronutrients (99 % for protein, 103 % for total fat). When compared with biomarkers, energy-adjusted coefficients were 0·34 for β-carotene and 0·33 for vitamin C.

The FFQ provides highly repeatable measurements and good validity in ranking individuals’ intake, suggesting that it will be a useful tool to assess nutrient intake of NZ adults in future research.

To validate a brief FFQ developed for capturing short-term antioxidant intake in a sample of US college students.

A seventy-four-item antioxidant FFQ was developed based on major antioxidant sources in the American diet. The FFQ was validated against 30 d food records (FR) and plasma antioxidant concentrations. The reliability of the FFQ was evaluated by two FFQ administered at a 1-month interval.

University of Connecticut, CT, USA.

Sixty healthy college students.

Estimates of dietary antioxidants from the FFQ were moderately to highly correlated with those estimated from the 30 d FR (r = 0·29–0·80; P < 0·05) except for γ-tocopherol and β-cryptoxanthin. Total antioxidant capacity from diet only or from diet and supplements estimated by the 30 d FR and FFQ were highly correlated (r = 0·67 and 0·71, respectively; P < 0·0001). The FFQ categorized 91 % of participants into the same or adjacent tertiles of antioxidant intake as the 30 d FR. Most dietary carotenoids estimated from the FFQ were correlated with plasma levels (P < 0·05). Correlation coefficients for test–retest reliability ranged from 0·39 to 0·86. More than 94 % of the participants were classified in the same or adjacent tertiles between the two administrations of the FFQ.

The brief FFQ demonstrated reasonable validity for capturing a comprehensive antioxidant intake profile. This FFQ is applicable in epidemiological or clinical studies to capture short-term antioxidant intake or to simply document the variations of antioxidant intake in intervention trials. Cross-validation studies are warranted in other target populations.

To examine associations among diet quality and dairy group membership, membership duration and non-member status for women and school-aged children in rural Kenya.

A cross-sectional survey, using chain referral sampling, was conducted and diet quality indices and prevalence of inadequate intake (PII) were estimated using the ‘estimated average requirement’ cut-off point method from single 24 h recalls, using a Kenyan nutrient database. PII was compared among members and non-members and among membership-duration groups.

Women and children of dairy group members (n 88), across membership-duration groups (1–3, 4–6, 7–9 and 10+ years), and non-members (n 23) living among members.

Small farms in central Kenya.

Members had higher energy, percentage of energy from animal-source foods and dietary diversity. Member women and children had lower PII for respectively seven and three of eleven micronutrients. Reduced PII for milk-source micronutrients was associated with membership duration for women. Many member women (38 %) had inadequate vitamin A intake and 39 % of member children had inadequate Zn intake. Members’ PII was also high (>45 %) for Fe, Ca and vitamin B12. A higher prevalence of being overweight among member women compared with non-member women suggested nutrition transition effects of higher farm productivity.

Dairy group membership was positively associated with adequate quantity and quality of diets for women and children. Long-term membership was insufficient to address micronutrient deficiencies. Understanding and addressing barriers to better diet quality and strategies to mitigate negative nutrition transition effects are needed to optimize nutritional outcomes of dairy group membership.

To examine whether home availability of energy-dense snack foods mediates the association between television (TV) viewing and energy-dense snack consumption among adolescents.

Cross-sectional.

Secondary schools in Victoria, Australia.

Adolescents (n 2984) from Years 7 and 9 of secondary school completed a web-based survey, between September 2004 and July 2005, assessing their energy-dense snack food consumption, school-day and weekend-day TV viewing and home availability of energy-dense snack foods.

School-day and weekend-day TV viewing were positively associated with energy-dense snack consumption among adolescent boys (β = 0·003, P < 0·001) and girls (β = 0·03, P < 0·001). Furthermore, TV viewing (school day and weekend day) were positively associated with home availability of energy-dense snack foods among adolescent boys and girls and home availability of energy-dense snack foods was positively associated with energy-dense snack food consumption among boys (β = 0·26, P < 0·001) and girls (β = 0·28, P < 0·001). Home availability partly mediated the association between TV viewing and energy-dense snack consumption.

The results of the present study suggest that TV viewing has a significant role to play in adolescent unhealthy eating behaviours. Future research should assess the efficacy of methods to reduce adolescent energy-dense snack food consumption by targeting parents to reduce home availability of energy-dense foods and by reducing TV viewing behaviours of adolescents.

While socio-economically disadvantaged adolescents tend to have poor dietary intakes, some manage to eat healthily. Understanding how some disadvantaged adolescents restrict high-energy foods and beverages may inform initiatives promoting healthier diets among this population. The present investigation aimed to: (i) identify disadvantaged adolescents’ high-energy food and beverage intakes; and (ii) explore cross-sectional and longitudinal associations between intrapersonal, social and environmental factors and disadvantaged adolescents’ high-energy food intakes.

Longitudinal online surveys were completed at baseline (2004–2005) and follow-up (2006–2007), each comprising a thirty-eight-item FFQ and questions examining intrapersonal, social and environmental factors.

Thirty-seven secondary schools in metropolitan and non-metropolitan Victoria, Australia.

Of 1938 adolescents aged 12–15 years participating at both time points, 529 disadvantaged adolescents (whose mothers had low education levels) were included in the present investigation.

At baseline and follow-up, respectively 32 % and 39 % of adolescents consumed high-energy foods less frequently (≤2 high-energy food meals/week); 61 % and 65 % consumed high-energy beverages less frequently (≤1 time/d). More girls than boys had less frequent high-energy food intakes, and baseline consumption frequency predicted consumption frequency at follow-up. Adolescents with less frequent consumption of high-energy foods and beverages seldom ate fast food for main meals, reported reduced availability of high-energy foods at home and were frequently served vegetables at dinner.

Nutrition promotion initiatives could help improve disadvantaged adolescents’ eating behaviours by promoting adolescents and their families to replace high-energy meals with nutritious home-prepared meals and decrease home availability of high-energy foods in place of more nutritious foods.

To determine the association of beverage consumption with obesity in Mexican American school-aged children.

Cross-sectional study using the baseline data from a cohort study. Mothers and children answered questions about the frequency and quantity of the child's consumption of soda, diet soda, other sugar-sweetened beverages, 100 % fruit juice, milk and water. The questions were adapted from the Youth/Adolescent FFQ. Children were weighed and measured. Data were collected on the following potential confounders: maternal BMI, household income, maternal education, maternal occupational status, maternal acculturation, child physical activity, child screen time and child fast-food consumption. Logistic regression was used to examine the association between servings (240 ml) of each beverage per week and obesity (BMI ≥ 95th percentile).

Participants were recruited from among enrolees of the Kaiser Permanente Health Plan of Northern California. Data were collected via an in-home assessment.

Mexican American children (n 319) aged 8–10 years.

Among participants, 20 % were overweight and 31 % were obese. After controlling for potential confounders, consuming more servings of soda was associated with increased odds of obesity (OR = 1·29; P < 0·001). Consuming more servings of flavoured milk per week was associated with lower odds of obesity (OR = 0·88; P = 0·004). Consumption of other beverages was not associated with obesity in the multivariate model.

Discouraging soda consumption among Mexican American children may help reduce the high obesity rates in this population.

The aim of the present study was to compare BMI and anthropometric indicators of abdominal obesity in Brazilian adolescents from public schools between 2003 and 2008.

A comparison of anthropometric indicators in adolescents was done based on two cross-sectional surveys conducted in 2003 (n 530) and in 2008 (n 498). BMI (= weight/height2), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were evaluated. The age-adjusted means were compared between the two studies by linear regression and the percentile values were compared by quantile regression. A P value <0·05 was adopted for statistical significance.

Metropolitan area of Rio de Janeiro, Brazil.

Two probabilistic samples of students aged 15–19 years old, from public schools.

There was a decrease in boys’ mean WC (72·9 cm v. 70·9 cm, P = 0·01) and an increase in girls’ mean BMI (21·1 kg/m2 v. 22·0 kg/m2, P = 0·03). Among boys, the WC, HC and WHtR percentiles were lower whereas the WHR percentiles were higher in 2008 than in 2003. Among girls, the percentiles of all measures were higher in 2008, except for WHR.

Anthropometric measures among boys tended to decrease, while among girls there was a tendency to increase from 2003 to 2008, indicating an important gender effect and a higher morbidity risk associated with excess body fat in girls. The school setting offers opportunities for interventions to address this situation.

The present study aimed to evaluate the prevalence of meeting health recommendations on diet and physical activity (having breakfast, eating fruit and vegetables, consumption of milk/yoghurt, performing moderate-to-vigorous physical activity, limiting television watching) and to assess junk snack food consumption in adolescents from southern Italy. The association between healthy behaviours and abdominal adiposity was also examined.

In a cross-sectional protocol, anthropometric data were measured by trained operators while other data were collected through a structured interview.

Three high schools in Naples, Italy.

A sample of 478 students, aged 14–17 years, was studied.

The proportion of adolescents who met each of the health recommendations varied: 55·4 % had breakfast on ≥6 d/week; 2·9 % ate ≥5 servings of fruit and vegetables/d; 1·9 % had ≥3 servings of milk/yoghurt daily; 13·6 % performed moderate-to-vigorous physical activity for ≥60 min/d; and 46·3 % watched television for <2 h/d. More than 65 % of adolescents consumed ≥1 serving of junk snack foods/d. Only 5 % fulfilled at least three recommendations. Healthy habits tended to correlate with each other. As the number of health recommendations met decreased, the percentage of adolescents with high abdominal adiposity (waist-to-height ratio ≥0·5) increased. The trend was not significant when the proportion of overweight/obese adolescents was considered. Logistic regression analysis indicated that male gender and watching television for ≥2 h/d were independently associated with a higher waist-to-height ratio.

Most adolescents failed to meet the five health recommendations considered. Male gender and excessive television watching were associated with abdominal adiposity.

Identifying risk factors for insulin resistance in adolescence could provide valuable information for early prevention. The study sought to identify risk factors for changes in insulin resistance and fasting blood glucose levels.

Prospective cohort of girls participating in the National Heart, Lung, and Blood Institute Growth and Health Study.

USA.

Adolescent girls (n 774) assessed at the ages of 16–17 and 18–19 years. Over a 3-year period, measurements of fasting blood glucose and insulin and serum cotinine were taken, and dietary intake (3 d food diary), smoking status and physical activity levels were self-reported.

Improvements in homeostasis model assessment of insulin resistance (HOMA-IR) were associated with increases in the percentage of energy intake from polyunsaturated fats (β = −3·33, 95 % CI −6·28, −0·39, P = 0·03) and grams of soluble fibre (β = −5·20, 95 % CI −9·81, −0·59, P = 0·03) between the ages of 16–17 and 18–19 years; with similar findings for insulin. Transitioning into obesity was associated with an increase in insulin (β = 6·34, 95 % CI 2·78, 9·91, P < 0·001) and HOMA-IR (β = 28·77, 95 % CI 8·13, 49·40, P = 0·006). Serum cotinine concentrations at 16–17 years, indicating exposure to tobacco, were associated with large increases (β = 15·43, 95 % CI 6·09, 24·77, P < 0·001) in fasting blood glucose concentrations.

Increases in the percentage of energy from polyunsaturated fat and fibre, and avoidance of excess weight gain and tobacco exposure, could substantially reduce the risk of insulin resistance in late adolescence.

To identify behavioural patterns of protective and risk factors for non-communicable diseases (NCD) and to explore the association between these patterns and sociodemographic characteristics.

Principal component analysis was used to identify behavioural patterns from a list of twelve protective and risk factors for NCD. Linear regression was used to explore the association between the patterns and sociodemographic characteristics.

Participants from the Brazilian Surveillance System of Risk and Protective Factors for NCD through Telephone Interviews (VIGITEL) from the years 2009 and 2010 were included.

A sample of 108 706 adults was included in the analysis.

Two behavioural patterns were identified in the analysis, a ‘prudent pattern’ and a ‘risky pattern’. The first involved mostly protective behaviours, while the second one involved essentially the risky ones. Both the less prudent and the more risky behaviour patterns were concentrated in younger men, with lower education, from the more developed region.

Public policies to decrease NCD should be aware of the possible tendency towards behavioural patterns in order to be more effective.

To assess the role of sociodemographic and nutritional factors in the incidence of births affected by neural tube defects (NTD) in the North Indian population.

Case–control study.

Government hospitals of Delhi, India.

Subjects comprised 284 mothers of NTD children (cases) and 568 mothers of healthy children (controls).

Significant differences were found between case and control mothers with respect to maternal age (P = 0·005), type of drinking water (P = 0·03) and consumption of milk (P = 0·01). Univariate and multivariate analysis suggested an association of unpasteurized milk use, low consumption of vegetables, low consumption of fruits and vegetarian dietary habits with NTD births. Further, variation in the risk factors for upper and lower NTD types was also observed, pointing towards phenotypic heterogeneity in the aetiology.

The results of the present study suggest an increased risk of NTD infants in mothers with low consumption of vegetables, fruits and milk and having vegetarian dietary habits. So, in order to reduce these devastating birth defects in future offspring, better nutritional care should be provided to mothers by suggesting dietary modifications and augmenting additional micronutrient supplementation during the periconceptional period.

The incidence of osteoporosis increases with age and is most frequently observed in postmenopausal women. The objective of the present population-based cohort study was to assess the influence of Ca intake from dairy sources on hip bone mineral density and hip fracture incidence in a group of Polish women over 55 years of age.

The main outcome measures included: bone mineral density, the number of previous fractures and the reported Ca intake from dairy sources, assessed by a diet questionnaire.

The RAC-OST-POL Study was conducted in the District of Raciborz in the south of Poland.

The study was carried out in a group of 625 women, randomly recruited from the general population of women aged >55 years.

Median Ca intake from dairy products was lower in the group of women with femoral neck T-score ≤–2·5 than in the group with T-score >–2·5 (275 v. 383 mg/d; P = 0·0019). For total hip score, the difference was close to borderline significance (P = 0·0698). Median Ca intake from dairy products was lower in the group of women with previous fractures than in those without fracture history (336 v. 395 mg/d; P = 0·0254). The main dairy source of Ca in the analysed group included milk drinks, rennet cheese and milk.

Higher dairy Ca intake is recommended, since a number of the women analysed were unable to satisfy their Ca requirement exclusively from their diet.

The aim of the present study was to examine the association between nutritional status and the incidence of disability regarding instrumental activities of daily living (IADL) among older adults.

The study is part of the longitudinal SABE (Saúde, Bem-Estar e Envelhecimento; Health, Wellbeing and Ageing) Study that began in 2000 (first wave) with a multistage, clustered, probabilistic sample (n 2143) of older adults (≥60 years). The second wave was carried out in 2006, when 1115 elders were re-interviewed. The dependent variable was the occurrence of disability in 2006 (report of difficulty on ≥1 IADL). Nutritional status (measured at baseline) was classified on the basis of BMI: ≤23·0 kg/m2 (underweight); >23·0 and <28·0 kg/m2 (ideal range – reference); ≥28·0 and <30·0 kg/m2 (overweight); and ≥30·0 kg/m2 (obesity).

São Paulo, Brazil.

One thousand and thirty-four individuals without difficulties regarding IADL in 2000 were selected, 611 of whom were re-interviewed in 2006.

In the multiple logistic regression analysis adjusted for baseline variables (gender, age, number of chronic diseases, stroke, osteoarthritis and cognitive status), underweight (OR = 2·03; P = 0·034) and obesity (OR = 1·79; P = 0·022) remained associated with disability.

Both underweight and obesity are associated with an increased risk of developing disability regarding IADL among older adults, in an independent fashion of other risk factors. Thus, adequate nutritional status is a key point to consider in the establishment of preventive measures.

Studies on the effects of Ramadan fasting on weight changes have been contradictory. We brought together all published data to comprehensively examine the effects in a systematic review and meta-analysis.

Relevant studies were obtained through searches of PubMed and CINAHL and by independent screening of reference lists and citations without any time restriction. All searches were completed between October and November 2011.

Changes in body weight during and after Ramadan were extracted from thirty-five English-language studies and were meta-analysed. Most of the studies were conducted in West Asia (n 19); the remainder were conducted in Africa (n 7), East Asia (n 3) and North America/Europe (n 4).

Healthy adults.

Fasting during Ramadan resulted in significant weight loss (−1·24 kg; 95 % CI −1·60, −0·88 kg). However, most of the weight lost was regained within a few weeks and only a slight decrease in body weight was observed in the following weeks after Ramadan compared with that at the beginning of Ramadan. Weight loss at the end of Ramadan was significant in both genders (−1·51 kg for men and −0·92 kg for women); but again the weight loss lasted no longer than 2 weeks after Ramadan. Weight loss during Ramadan was greater among Asian populations compared with Africans and Europeans.

Weight changes during Ramadan were relatively small and mostly reversed after Ramadan, gradually returning to pre-Ramadan status. Ramadan provides an opportunity to lose weight, but structured and consistent lifestyle modifications are necessary to achieve lasting weight loss.

The aim of the present study was to review the methodological literature regarding evaluation methods for complex public health interventions broadly and, based on such methods, to critically reflect on the evaluation of contemporary community-based obesity prevention programmes.

A systematic review of the methods and community-based literature was performed by one reviewer.

The review identified that there is considerable scope to improve the rigour of community-based obesity prevention programmes through: prospective trial registration; the use of more rigorous research designs, particularly where routine databases including an objective measure of adiposity are available; implementing strategies to quantify and reduce the risk of selective non-participation bias; the development and use of validated instruments to assess intervention impacts; reporting of intervention process and context information; and more comprehensive analyses of trial outcomes.

To maximise the quality and utility of community-based obesity prevention evaluations, programme implementers and evaluators need to carefully examine the strengths and pitfalls of evaluation decisions and seek to maximise evaluation rigour in the context of political, resource and practical constraints.