Dietary assessment has been used for certification to receive food supplements or other nutrition services and to provide feedback for educational purposes. The proportion of individuals correctly certified as eligible is a function of the amount of error that exists in the dietary measures and the level of dietary intake used to establish eligibility. Whether individuals are correctly counselled to increase or decrease the consumption of selected foods or nutrients is a function of the same factors. It is not clear, however, what percentage of individuals would be correctly classified under what circumstances. The objective of this study is to demonstrate the extent to which measurement error and eligibility criteria affect the accuracy of classification.

Hypothetical distributions of dietary intake were generated with varying degrees of measurement error. Different eligibility criteria were applied and the expected classification rates were determined using numerical methods.

Simulation study.

Cut points of dietary intake at decreasing levels below the 50th percentile of true intake were associated with lower sensitivity and predictive value positive rates, but higher specificity and predictive value negative rates. The correct classification rates were lower when two cut points of dietary intake were used. Using a single cut point that was higher than the targeted true consumption resulted in higher sensitivity but lower predictive value positive, and lower specificity but higher predictive value negative.

Current methods of dietary assessment may not be reliable enough to attain acceptable levels of correct classification. Policy-makers and educators must consider how much misclassification error they are willing to accept and determine whether more intensive methods are necessary.

To identify consumer attitudes and beliefs about (liquid) milk that may be barriers to consumption.

Two random-quota telephone surveys conducted in Auckland one year apart. Respondents were questioned about their usual milk intake and their attitudes to milk. The questionnaire included attitude items that reflected the main themes of consumer interest in milk.

New Zealand.

Seven hundred and thirteen respondents in the baseline survey and a separate sample of 719 respondents in the follow-up survey.

At least one-third of the respondents consumed less than a glass (250ml) of milk a day. Non-consumption was highest in young women (15%). People's concerns about milk related to what was important in their lives; what threatens them physically and emotionally. Women held more positive attitudes but they were concerned about the fat content of milk. Men were less aware of milk's nutritional benefits and as a result were less appreciative of its value.

There is an opportunity to develop public health initiatives to address the barriers to drinking milk. Industry–health alliances may be an effective means to provide positive nutrition messages about milk and to engage the support of health professionals.

To examine the prevalence and dietary, sociodemographic and lifestyle risk factors of low iron intake and poor iron status in British young people.

National Diet and Nutrition Survey of young people aged 4–18 years.

Great Britain, 1997.

In total, 1699 young people provided 7-day weighed dietary records, of which 11% were excluded because the participant reported being unwell with eating habits affected. Blood was obtained from 1193 participants, with iron status indicated by haemoglobin, serum ferritin and transferrin saturation.

Iron intakes were generally adequate in most young people aged 4–18 years. However, low iron intakes (below the Lower Reference Nutrient Intake) occurred in 44% of adolescent girls (11–18 years), being less prevalent with high consumption of breakfast cereals. Low haemoglobin concentration (<115 gl−1, 4–12 years; <120 or <130 gl−1, 13+ years for girls and boys, respectively) was observed in 9% of children aged 4–6 years, pubertal boys (11–14 years) and older girls (15–18 years). Adolescent girls who were non-Caucasians or vegetarians had significantly poorer iron status than Caucasians or meat eaters, independent of other risk factors. The three iron status indices were correlated significantly with haem, but not non-haem, iron intake.

Adolescent girls showed the highest prevalence of low iron intake and poor iron status, with the latter independently associated with non-Caucasian ethnicity and vegetarianism. Risk of poor iron status may be reduced by consuming (particularly lean red) meat or enhancers of non-haem iron absorption (e.g. fruit or fruit juice) in vegetarians.

To identify consumer perceptions of whole milk, reduced-fat milk and soy milk, and to investigate demographic influences on perceptions and types of milk consumption.

Questionnaires covering nutritional and sensory perceptions of three types of milk.

Three hundred and sixty-one randomly selected shoppers in Melbourne, Australia.

Generally, respondents held positive perceptions about milk. Milk was considered as having good sensory properties, providing a good source of nutrients, and being a convenient and safe product. However, despite these findings, misperceptions and unawareness about the nutrient content of milk were prevalent. Negative perceptions were most common for whole milk and were mostly related to its perceived high fat, cholesterol and energy contents. Soy milk received lower ratings on sensory quality and convenience than dairy milk. There were few sociodemographic differences in consumers' perceptions. Although reduced-fat milk consumption was more frequent among elderly people and type of milk consumption was related to parenthood, no other significant effects of demographic variables were found on the consumption of specific milk types.

Although positive perceptions were common, negative perceptions and misperceptions appear to be prevalent, presenting a challenge for nutrition education. Sociodemographic factors were not shown to be important predictors of perceptions and type of milk consumption.

To estimate the intake of refined sugar in Australian children and adolescents, aged 2–18 years.

Foods contributing to total sugar intake were identified using data from the National Nutrition Survey 1995 (NNS95), the most recent national dietary survey of the Australian population. The top 100 foods represented means of 85% (range 79–91%) and 82% (range 78–85%) of total sugar intake for boys and girls, respectively. Using published Australian food composition data (NUTTAB95), the proportion of total sugar being refined sugar was estimated for each food. Where published food composition data were not available, calculations from ingredients and manufacturer's information were used.

The NNS95 assessed the dietary intake of a random sample of the Australian population, aged 2–18 years (n = 3007).

Mean daily intakes of refined sugar ranged from 26.9 to 78.3 g for 2–18-year-old girls, representing 6.6–14.8% of total energy intake. Corresponding figures for boys were 27.0 to 81.6 g and 8.0–14.0%, respectively. Of the 10 highest sources of refined sugar for each age group, sweetened beverages, especially cola-type beverages, were the most prominent.

Refined sugar is an important contributor to dietary energy in Australian children. Sweetened beverages such as soft drinks and cordials were substantial sources of refined sugar and represent a potential target for campaigns to reduce refined sugar intake. Better access to information on the amounts of sugar added to processed food is essential for appropriate monitoring of this important energy source.

To examine associations of changes in dietary intake with education in young black and white men and women.

The Coronary Artery Risk Development in Young Adults (CARDIA) study, a multi-centre population-based prospective study. Dietary intake data at baseline and year 7 were obtained from an extensive nutritionist-administered diet history questionnaire with 700 items developed for CARDIA.

Participants were recruited in 1985–1986 from four sites: Birmingham, Alabama; Chicago, Illinois; Minneapolis, Minnesota; and Oakland, California.

Participants were from a general community sample of 703 black men (BM), 1006 black women (BW), 963 white men (WM) and 1054 white women (WW) who were aged 18–30 years at baseline. Analyses here include data for baseline (1985–1986) and year 7 (1992–1993).

Most changes in dietary intake were observed among those with high education (≥ 12 years) at both examinations. There was a significant decrease in intake of energy from saturated fat and cholesterol and a significant increase in energy from starch for each race-gender group (P < 0.001). Regardless of education, taste was considered an important influence on food choice.

The inverse relationship of education with changes in saturated fat and cholesterol intakes suggests that national public health campaigns may have a greater impact among those with more education.

To calculate the sensitivity, specificity and agreement of body mass index (BMI) values proposed by Cole et al. (Br. Med. J. 2000; 320: 1) and Must et al. (Am. J. Clin. Nutr. 1991; 53: 839 & 54: 773) with weight-for-height index in the nutritional evaluation of children.

Criterion standards for diagnostic tests.

North-east and south-east Brazil.

Two thousand nine hundred and twenty children studied in Life Pattern Research performed by the Brazilian Institute of Geography and Statistics in 1997. Main outcome measures are the sensitivity, specificity and agreement of BMI values proposed by Must et al. (1991) and Cole et al. (2000).

Sensitivity of values proposed by both authors was around 90%. Specificity was almost 100% considering weight-for-height index as the gold standard. The agreement of both values with weight-for-height index, based on kappa results, was good and in pre-school children it was excellent.

Values proposed by Cole et al. (2000) and Must et al. (1991) should be used carefully to screen obesity in childhood but can be used to ‘diagnose’ overweight children with a very low chance of having false-positive results. Although the values proposed by both authors performed similarly, use of Cole et al.'s values should be encouraged. The latter cover children from 2 to 6 years old; their values are presented for six-month age intervals; they are based on a larger sample from six different countries; and they are related to the definition of adult obesity.

To investigate the attitudes, experiences and beliefs of advanced-level public health nutritionists with respect to public health nutrition workforce composition, core functions, competency requirements and existing workforce capacity.

Qualitative study using structured interviews.

Australia.

Forty-one advanced-level public health nutritionists employed in academic and senior technocratic positions in state health systems.

Advanced-level public health nutritionists recognise the diversity of the public health nutrition workforce but clearly identify the need for a specialist public health nutrition workforce tier to provide workforce leadership. Nominated core functions for public health nutrition reflect broader public health core functions but, in the context of nutrition, specific problem resolution. Opinions about competency needs were similar to many of the cross-cutting competencies identified in the public health field but with specific application to nutrition problems. Competency in the scientific underpinning of nutrition was considered particularly important and delineated this public health nutrition workforce from the broader public health workforce. Public health nutrition was identified as a specialisation within public health and dietetics. Workforce capacity assessments by this group indicate a need for workforce development.

Qualitative data from a large proportion of the Australian public health nutrition leadership group have identified core functions, competencies and workforce development priorities that can be a basis for further systematic research and workforce strategy development.

To develop a nutritional dietary intake database based on available reliable international nutritional databases adapted to the local needs of a specific population.

The Negev Nutritional Study (NNS) is a survey of a random sample of the Negev population regarding their dietary intake using 24-hour dietary recalls. A nutritional database for the Israeli population was developed based on adaptation and modification of the US Department of Agriculture's database. A data-entry system was developed based on the logic of the US Food Information Analysis System. The system was designed as bilingual (English and Hebrew). Local foods and recipes were collected during the NNS, which included 1465 24-hour diet interviews.

During the course of the NNS, 383 basic Israeli recipes were constructed. In total 1362 Israeli products were added to the database, and each was given a code, specific gravity and portion size. Most of the added products were cereals and grains and dairy products. The added recipes were collected from the interviewees in the NNS and from the most popular cookbooks.

This paper describes the process undertaken to develop an Israeli food composition database as well as the data-entry system. This knowledge may aid other research groups in developing a computerised, nation-specific nutritional database and data-entry system adapted to their own specific local needs.

Availability of confectionery from vending machines in secondary schools provides a convenient point of purchase. There is concern that this may lead to ‘over-indulgence’ and hence an increase in susceptibility to obesity and poor ‘dietary quality’. The study objective was to investigate the association between the frequency of consumption of confectionery purchased from vending machines and other sources and related lifestyle factors in adolescent boys and girls.

A secondary school-based, cross-sectional study.

A total of 504 subjects were investigated (age range 12–15 years), from three schools in southern and northern England. Using a lifestyle questionnaire, frequency of confectionery consumption (CC) from all sources (AS) and vending machines (VM) was recorded for a typical school week. Subjects were categorised into non-consumers, low, medium and high consumers using the following criteria: none, 0 times per week; low, 1–5 times per week; medium, 6–9 times per week; high, 10 times per week or greater.

No differences were found in the frequency of CC from AS or VM between those who consumed breakfast and lunch and those who did not. No differences were found in the frequency of fruit and vegetable intake in high VM CC vs. none VM CC groups, or in any of the VM CC groups. Confectionery consumption from AS (but not VM) was found to be higher in subjects who were physically active on the journey to school (P <0.01) but also higher in those who spent more time watching television and playing computer games (P <0.01). No associations were found between smoking habits or alcohol consumption and frequency of CC.

These results do not show a link between consumption of confectionery purchased from vending machines and ‘poor’ dietary practice or ‘undesirable’ lifestyle habits. Findings for total confectionery consumption showed some interesting trends, but the results were not consistent, either for a negative or positive effect.

For proper interpretation of results from epidemiological studies that use food-frequency questionnaires (FFQs), it is necessary to know the relationship between reported intakes from the FFQ and true usual intake. In this paper, we report a calibration study conducted to investigate the performance of the FFQ used in a cohort study, the Canadian Study of Diet, Lifestyle and Health.

Over a 1-year period, 151 men and 159 women completed a full set of questionnaires including a self-administered baseline FFQ, three 24-hour diet recalls administered by telephone, and a second FFQ self-administered subsequently. The association between the nutrient estimates derived from the FFQs and the diet recalls was evaluated by calculating deattenuated Pearson's correlation coefficients.

The FFQs estimated mean daily nutrient intakes higher than the diet recalls. When the log-transformed and energy-adjusted nutrient intakes from the average of three 24-hour recalls were compared against the baseline FFQ, the following deattenuated correlations were obtained in men and women, respectively: total energy 0.44 and 0.32, total fat 0.64 and 0.68, saturated fat 0.68 and 0.70, dietary fibre 0.65 and 0.44, vitamin E 0.32 and 0.37, vitamin C 0.40 and 0.37, β-carotene 0.34 and 0.29, alcohol 0.74 and 0.67, caffeine 0.81 and 0.76, with a median correlation of 0.49 and 0.53. Correlations between the second FFQ and diet recalls were similar. The correlations between the two FFQs as a test of reliability had a median value 0.64 for men and 0.63 for women for selected nutrients.

The study suggests that the FFQ method gives acceptable levels of nutrients or food component estimates, as assessed by this calibration study against diet recalls, when limited to energy-adjusted and deattenuated values.

To compare different statistical methods for assessing the relative validity of a self-administered, 150-item, semi-quantitative food-frequency questionnaire (FFQ) with 4-day weighed diet records (WR).

Subjects completed the Scottish Collaborative Group FFQ and carried out a 4-day WR. Relative agreement between the FFQ and WR for energy-adjusted nutrient intakes was assessed by Pearson and Spearman rank correlation coefficients, the percentages of subjects classified into the same and opposite thirds of intake, and Cohen's weighted kappa.

Forty-one men, mean age 36 (range 21-56) years, and 40 women, mean age 33 (range 19-58) years, recruited from different locations in Aberdeen, Scotland.

Spearman correlation coefficients tended to be lower than Pearson correlation coefficients, and were above 0.5 for 10 of the 27 nutrients in men and 17 of the 27 nutrients in women. For nutrients with Spearman correlation coefficients above 0.5, the percentage of subjects correctly classified into thirds ranged from 39 to 78%, and weighted kappa values ranged from 0.23 to 0.66.

Both Spearman correlation coefficients and weighted kappa values are useful in assessing the relative validity of estimates of nutrient intake by FFQs. Spearman correlation coefficients above 0.5, more than 50% of subjects correctly classified and less than 10% of subjects grossly misclassified into thirds, and weighted kappa values above 0.4 are recommended for nutrients of interest in epidemiological studies.

Intake of sugars is restricted in most international food guides. However, in recent recommendations quantified limits of added sugars intake have not been given, although deemed necessary by those who criticised the recommendations.

Two approaches to derive a scientifically based quantified limit of added sugars intake for German children and adolescents are suggested. For the first dietary survey approach, 5120 three-day weighed dietary records from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study were used. Added sugars intakes in records of high vs. low dietary quality, measured by a nutrient intake score, were compared. For the second approach, a total dietary concept for German children and adolescents developed and evaluated by the Research Institute of Child Nutrition – the Optimised Mixed Diet – was used.

Whereas in the latter dietary concept an added sugars intake of about 6% of energy intake is tolerated, the dietary survey approach resulted in only small differences between high and low dietary quality, with a median added sugars intake of 12% of energy in records with high dietary quality.

A reasonable dietary quality is possible within higher ranges of added sugars intake than derived from the dietary concept approach. Therefore we suggest a range of intake of added sugars for German children and adolescents, from 6% to 12% of energy.

To assess the level of agreement amongst a panel of public health nutrition leaders regarding the key descriptors used to define the field of public health nutrition.

Cross-sectional survey requiring quantitative and qualitative responses representing the first round of a consensus development Delphi technique.

International.

Expert panel of 24 public health nutrition leaders from nine countries in the European Union, the USA and Australia.

All but one of the panel agreed it was important to have a consensus definition for public health nutrition to describe the field consistently. Opinion about the length and complexity of this definition tended to vary depending on the intended use of the definition. The large majority (18/24) supported the inclusion of specific reference to physical activity in a definition of public health nutrition, although there was not consensus (>83% agreement as criterion) on this point. Consensus descriptors regarded as important in a definition of public health nutrition included: population-based, focus on health promotion, food and nutrition systems focus, wellness maintenance, primary prevention, applies public health principles, education, environmental and political descriptors. Treatment as a descriptor was rated as unimportant by a majority (14/24) of panellists, delineating public health nutrition from clinical practice.

There is strong international agreement amongst public health nutrition leaders in Europe, the USA and Australia about a range of descriptors that can be used to define public health nutrition. The limitations of using word-for-word definitions between and within countries may be overcome by explicit use of the consensus descriptors identified in this process.

To examine associations between breakfast cereal consumption and the dietary habits, nutrient intakes and nutritional status of young people, considering both nutrient adequacy and safety issues (fortification).

Using archived data from 1688 children in the (British) National Diet and Nutrition Survey of Young People aged 4 to 18 years, nutrient intakes and status were compared across thirds of breakfast cereal consumption (T1 to T3), adjusted for age and energy intake. Cereals provided on average 2%, 6% and 12% of energy in T1, T2 and T3, respectively, for boys; 1%, 4% and 10%, respectively, for girls.

Intakes of iron, B vitamins and vitamin D were around 20–60% higher in T3 compared with T1, with significant linear relationships observed for iron, thiamin, riboflavin and folate (T1 < T2 < T3). After excluding low energy reporters and the unwell, 14% of girls had iron intakes below the Lower Reference Nutrient Intake and this varied fivefold between T1 and T3 (27%, 12% and 5%; P = 0.0001). High consumers of breakfast cereals (T3) had better folate, vitamin B12 and riboflavin status and lower total and low-density lipoprotein cholesterol. There was also an association with thiamin and vitamin B6 status in girls. However, iron status (haemoglobin, ferritin and transferrin saturation) was not significantly different between groups, possibly due to lower meat intakes in T3. Total iron intakes were within tolerable levels (maximum of 32 mg day−1 in one girl taking supplements).

The nutritional benefits of breakfast cereals are demonstrated in status measurements as well as in nutrient intakes in this study. Concerns about excessive iron intakes from fortification appear unjustified.

The aim of this study was to evaluate the effectiveness of a widespread vitamin A supplementation programme and to describe indicators of compliance with the programme in Indonesia.

Prospective cohort study. Children's anthropometric data were gathered at baseline (June 2000) and 4 months later (2 months after supplementation in August 2000). Serum retinol, haemoglobin, ferritin, α1-acid glycoprotein and C-reactive protein were measured at baseline and at follow-up. Caregivers of the children were interviewed using a questionnaire.

Semi-urban and rural areas of Semarang district, Central Java, Indonesia.

Children (n = 400) aged 1–5 years.

After the supplementation, the proportion of children with a low concentration of retinol decreased in recipients from 18.8 to 14.5%. However, in non-recipients, the prevalence of vitamin A deficiency increased from 31.9 to 37.5%, this prevalence being significantly higher than in recipients. A significant decrease occurred in the proportion of recipients with low ferritin (26.5 to 16.2%) and haemoglobin (25.7 to 15.3%), whereas the proportions did not show a significant change after supplementation for non-recipients. Modest linear growth was detected in recipients after supplementation but there was no effect on ponderal growth. The coverage rate of the supplementation in the study areas was 60%. There was an association between compliance of the caregivers and their knowledge about the potential benefit of vitamin A supplementation, the place where sick children were taken and age of the children.

The vitamin A supplementation programme marginally decreased the proportion of vitamin A deficiency and had a marginal effect on the nutritional status of recipients. More than one micronutrient intervention is needed to increase the effectiveness of the supplementation programme. To increase compliance and coverage in the supplementation programme, nutrition communication and private healthcare practices need to be included in the programme.

To assess the reproducibility and validity a 127-item, habitual intake, food-frequency questionnaire (FFQ), developed for low-income and low-literacy Brazilian workers, by comparison with a 24-hour dietary recall (24-HDR).

The FFQ and 24-HDR were interviewer-administered at the local workplace to each subject twice, with a period of 6 months between estimates; and four 24-HDRs were conducted during the 4-month period between the two FFQs (FFQ1 and FFQ2). Reproducibility was tested by comparing mean nutrient intakes from the two FFQs. Validity was determined by comparing the mean nutrient intakes from the FFQs with the corresponding averages of the six 24-HDRs (reference method).

Goiânia City, in Central West Brazil.

The study was based on 104 (62 women and 42 men) subjects, aged 18 to 60 years, who were randomly selected.

Dietary intake from the FFQ was higher than from the 24-HDR. Reproducibility was assessed by Pearson correlation coefficients for nutrients from FFQ1 and FFQ2, and ranged from 0.23 for retinol to 0.69 for total energy (mean 0.52). Intra-class coefficients for nutrients averaged by the 24-HDRs ranged from 0.29 for vitamin C to 0.76 for total energy; retinol was not significant. In the validation study, correlation between the FFQ and the 24-HDR ranged between 0.21 for vitamin C and 0.70 for total energy (mean 0.50). Adjusting for total energy lowered the coefficients, except for calcium, retinol and vitamin C. Coefficients increased with attenuation, ranging from 0.35 for carbohydrate to 0.65 for calcium.

Results indicate that this questionnaire had satisfactory reproducibility and reasonable validity.

To examine associations of biomarkers of nutrient intake with overall diet quality.

A convenience sample of 102 healthy postmenopausal women in Seattle, Washington (USA).

Participants attended a study centre where they provided fasting blood specimens and completed a 122-item validated food-frequency questionnaire (FFQ). Data from the FFQ were used to calculate Diet Quality Index (DQI) scores and categorise women as having diets of excellent, good, fair or poor quality. The blood specimens were analysed for nine phospholipid fatty acids (as percentage of total) and serum concentrations of vitamin C, α-tocopherol, γ-tocopherol, vitamin B12, folate and six carotenoids. Multivariate linear regression was used to model associations of the nutrient biomarkers with DQI scores.

Compared with women with poor-quality diets, women with excellent diets, as measured by the DQI, had higher plasma concentrations of vitamin C (P for trend = 0.01), α-tocopherol (P for trend = 0.02) and β-cryptoxanthin (P for trend = 0.03). Women with excellent diets also had lower proportions of plasma phospholipid fatty acids of two potentially atherogenic fatty acids: stearic acid (P for trend = 0.01) and behenic acid (P for trend = 0.03). A group of six biomarkers explained a moderate proportion of the total variability in DQI scores (36%).

These objective measures of dietary intake support the use of the DQI as a useful tool to measure dietary patterns.

An extensive dataset on individual food consumption was analysed in order to study all pairwise correlations between the consumption rates of 11 major food groups. Additionally, the project aimed to examine and quantify the accuracy of a recently proposed estimator of total food consumption to be used for the estimation of radiation exposure by food. Such an inquiry seems justified, because the proposed estimator implicitly presumes an essentially positive correlation structure in food consumption rates.

Statistical analysis using representative data gathered in Germany in a nation-wide food consumption survey.

Germany.

Individuals aged between 4 and 94 years namely 10901 males and 12308 females.

The consumption rates of 11 major food categories showed several significantly positive, but also a number of significantly negative, correlations. Negative associations between cereal and potato products persisted consistently over all age groups, independent of sex. Other significantly negative correlations were limited to certain age groups. Reflecting these negative correlations, a subsequent analysis of relative ranks of consumption revealed that no person in the sample had the highest consumption rates in all food groups simultaneously. Based on representative samples, overestimations of 34 to 53% were obtained if – as recently suggested in the context of radiation exposure prediction – the 95th percentiles of total food consumption were determined as sums of the corresponding percentiles of the food groups.

The complex correlation structure of food group consumption rates, as identified in this study, bears important implications for various health-related issues. Ignoring them could lead to overly conservative estimations of radiation exposure due to food ingestion or to confounding effects in epidemiological studies on nutritional risk factors of diseases. The results also indicate that a distinction into different dietary patterns might be useful in characterising different consumption habits.

To assess the validity and repeatability of a simple index designed to rank participants according to their energy expenditure estimated by self-report, by comparison with objectively measured energy expenditure assessed by heart-rate monitoring with individual calibration.

Energy expenditure was assessed over one year by four separate episodes of 4-day heart-rate monitoring, a method previously validated against whole-body calorimetry and doubly labelled water. Cardio-respiratory fitness was assessed by four repeated measures of sub-maximum oxygen uptake. At the end of the 12-month period, participants completed a physical activity questionnaire that assessed past-year activity. A simple four-level physical activity index was derived by combining occupational physical activity together with time participating in cycling and other physical exercise (such as keep fit, aerobics, swimming and jogging).

One hundred and seventy-three randomly selected men and women aged 40 to 65 years.

The repeatability of the physical activity index was high (weighted kappa = 0.6, P < 0.0001). There were positive associations between the physical activity index from the questionnaire and the objective measures of the ratio of daytime energy expenditure to resting metabolic rate (P = 0.003) and cardio-respiratory fitness (P = 0.001). As an indirect test of validity, there was a positive association between the physical activity index and the ratio of energy intake, assessed by 7-day food diaries, to predicted basal metabolic rate.

The summary index of physical activity derived from the questions used in the European Prospective Investigation into Cancer and Nutrition (EPIC) study suggest it is useful for ranking participants in terms of their physical activity in large epidemiological studies. The index is simple and easy to comprehend, which may make it suitable for situations that require a concise, global index of activity.