Who are the 'low energy reporters' in the dietary and nutritional survey of British adults?

Comparaison de deux enquêtes nationales de consommations alimentaires (INCA 1 1998/99 et Baromètre santé nutrition 2002) au regard de cinq objectifs alimentaires du Programme national nutrition santé

BACKGROUND

Monitoring the dietary intake of the French population requires the implementation and regular renewal of representative national survey. As these surveys can use different methodologies (food frequency questionnaire, 24 hour recall, 3 or 7-day dietary record...), it seems useful to check whether they supply similar results. The aim of this study is to determine whether two representative national surveys with different methodologies can be used alternately to monitor changes in food consumption of the French population.

METHOD

Percentages of consumers aged 15-75 were compared between two national food surveys (Health Nutrition Barometer 2002 and INCA 1 1998-99) with respect to five food frequency recommendations of the French National Nutrition and Health Program.

RESULTS

The same public health priorities were found in both surveys: the food groups were graded according to the same hierarchy of adequate food intake prevalences (ascending: fruits and vegetables, dairy products, fish, starchy foods and meat-fish-egg products). On the other hand, significant statistical different elements were pointed out in a few food groups which may be explained by methodological patterns. Definitions of portions and food groups, survey duration and seasons are indeed important parameters to be considered when comparing surveys.

CONCLUSION

The results show the need to elaborate standardized methods for comparison of food consumption surveys, which can be useful for the evaluation of the national nutritional recommendations. The methodological limitations described in this study also indicate that the quantitative description of food intake trends should improve when established by the results of the same regularly repeated survey.

Evaluation of dietary intake data using the tolerable upper intake levels

We discuss the problem of assessing nutrient intake relative to the tolerable upper intake levels (UL) for the nutrient proposed by the Institute of Medicine and focus on 2 important topics: the estimation of usual nutrient intake distributions and the extent to which intakes above the UL can be considered risky. With the information that is currently available for most nutrients, it is not possible to estimate the proportion of individuals in a group with intakes that place them at risk. This is because the shape of the dose-response curve needed to carry out a risk assessment is unknown for most nutrients. Thus, intakes above UL cannot be declared to be unsafe. Intakes below the UL, however, are likely to pose no risk to individuals in the group. Because determining the proportion of individuals with intakes below the UL requires estimation of an upper-tail percentile of the intake distribution, the use of 1-d intake data or otherwise unadjusted intake data are likely to lead to severely biased estimates. It is important to remove within-individual variance in intakes from daily intakes so that the tails of the usual intake distribution are accurately estimated. Underreporting of the amount of nutrients consumed will tend to shift the estimated usual nutrient intake distribution downwards. In this case, the true proportion of individuals with intakes below the UL is likely to be overestimated.

The Psychosocial and Behavioral Characteristics Related to Energy Misreporting

Energy underreporting occurs in 2% to 85% and overreporting in 1% to 39% of various populations. Efforts are needed to understand the psychosocial and behavioral characteristics associated with misreporting to help improve the accuracy of dietary self-reporting. Past research suggests that higher social desirability and greater eating restraint are key factors influencing misreporting, while a history of dieting and being overweight are more moderately associated. Eating disinhibition, body image, depression, anxiety, and fear of negative evaluation may be related to energy misreporting, but evidence is insufficient. This review will provide a detailed discussion of the published associations among psychosocial and behavioral characteristics and energy misreporting.

Attainment of precision in implementation of 24 h dietary recalls: INTERMAP UK

Collection of complete and accurate dietary intake data is necessary to investigate the association of nutrient intakes with disease outcomes. A standardised multiple-pass 24 h dietary recall method was used in the International Collaborative Study of Macro- and Micronutrients and Blood Pressure (INTERMAP) to obtain maximally objective data. Dietary interviewers were intensively trained and recalls taped, with consent, for randomly selected evaluations by the local site nutritionist (SN) and/or country nutritionists (CN) using a twelve-criterion checklist marked on a four-point scale (1, retrain, to 4, excellent). In the Belfast centre, seven dietary interviewers collected 932 24 h recalls from 40-59-year-old men and women. Total scores from the 134 evaluated recalls ranged from thirty-four to the maximum forty-eight points. All twelve aspects of the interviews were completed satisfactorily on average whether scored by the SN (n 53, range: probing 3.25 to privacy of interview 3.98) or CN (n 19, range: probing 3.26 to pace of interview and general manner of interviewer 3.95); the CN gave significantly lower scores than the SN for recalls evaluated by both nutritionists (n 31, Wilcoxon signed rank test, P=0.001). Five evaluations of three recalls identified areas requiring retraining or work to improve performance. Reporting accuracy was estimated using BMR; energy intake estimates less than 1.2 x BMR identifying under-reporting. Mean ratios in all age, sex and body-mass groups were above this cut-off point; overall, 26.1 % were below. Experiences from the INTERMAP Belfast centre indicate that difficulties in collection of dietary information can be anticipated and contained by the systematic use of methods to prevent, detect and correct errors.

Energy density of diets reported by American adults: association with food group intake, nutrient intake, and body weight

OBJECTIVE

Recent reports suggest that dietary energy density may play a role in regulation of food intake. However, little is known about the energy density of diets consumed by free-living populations; therefore, the purpose of this study was to examine demographic, health, and nutritional correlates of energy density of self-reported diets.

RESEARCH METHODS AND PROCEDURES

Using data from the NHANES III (n=13 400), dietary energy density was defined three ways: (1) energy content (kJ/g) of all foods and beverages reported or ED1, (2) energy content (kJ/g) of all foods and energy yielding beverages or ED2, and (3) energy content (kJ/g) of all foods (no beverages) or ED3. Multiple linear or logistic regression methods were used to examine the association of energy density with intake of energy, nutrients, food groups, and body mass index (BMI). We computed the ratios of within- to between-person variance for the three energy density variables using the second recall obtained from the second exam subsample of NHANES III (n=1037).

RESULTS

The mean ED1, ED2, and ED3, respectively, were 3.84+/-0.02, 5.45+/-0.03, and 8.03+/-0.03. Dietary intakes of energy, fat, and low-nutrient-density foods were related positively, but amounts of micronutrients, fruit, and vegetables were related inversely with all types of energy density (P<0.0001). ED2 and ED3 were modest positive predictors of BMI in both men and women (P< or =0.03). The ratios of within- to between-person components of variance for ED1, ED2, and ED3 were 1.34, 2.05, and 1.53, respectively.

DISCUSSION

High-energy-density diets in the US were characterized by low fruit and vegetable intake, and high BMI.

Secular trends in under-reporting in young people

National survey data show that reported energy intake has decreased in recent decades despite a rise in the prevalence of obesity. This disparity may be due to a secular increase in under-reporting or a quantitatively greater decrease in energy expenditure. This study examines the extent of under-reporting of energy intake in the National Diet and Nutrition Survey (NDNS) in young people aged 4-18 years in 1997 using published equations to calculate estimated energy requirements. It explores secular changes by comparison with the Diets of British School Children (DBSC) survey in 10-11- and 14-15-year-olds in 1983. In the NDNS, under-reporting (estimated energy requirements--energy intake) represented 21 % of energy needs in girls and 20 % in boys. The magnitude of under-reporting increased significantly with age (P<0.001) and was higher in overweight than lean individuals over 7 years of age. To compare reported energy intake in DBSC and NDNS, the estimated physical activity level from dietary records (dPAL=reported energy intake/predicted BMR) was calculated. If there were no under-reporting, dPAL would represent the subject's true activity level. However, dPAL from the NDNS was significantly lower than that from the DBSC by 8 % and 9 % in boys and girls for those aged 10-11 years, and by 14 % and 11 % for 14-15-year-olds respectively, reaching physiologically implausible levels in the 14-15-year-old girls (dPAL=1.17). If activity levels have remained constant between the two surveys, under-reporting has increased by 8-14 %. The evidence supports a secular trend towards increased under-reporting between the two surveys, but the precise magnitude cannot be quantified in the absence of historical measures of energy expenditure.

Dietary patterns and lifestyle factors in the Norwegian EPIC cohort: The Norwegian Women and Cancer (NOWAC) study

OBJECTIVE

To identify different dietary patterns in Norway using a combination of cluster and factor analysis.

DESIGN

Cross-sectional study.

SETTING

Nation-wide, population-based study.

SUBJECTS

The Norwegian EPIC cohort is a subcohort of the Norwegian Women and Cancer study (NOWAC), and consist 37.226 women aged 41-56 y who answered a food frequency questionnaire (FFQ) in 1998.

INTERVENTIONS

The associations among 50 food variables were first investigated by using principal component analysis. Five important factors were found. The five principal components were then used as input in the cluster analysis. Different socioeconomic and lifestyle variables were examined.

RESULTS

Six clusters of dietary patterns were found, and were labelled accordingly: 'traditional fish eaters', 'healthy eaters', 'average, less fish, less healthy', 'Western', 'traditional bread eaters', and 'alcohol users'. The traditional fish eaters and the traditional bread eaters were both highly represented in the north and west of Norway and were more likely to be present among persons with lower income and lower education. The healthy and the alcohol drinkers were found mostly in the south and east and were more likely to have higher income. Persons in the alcohol group were more likely to be current smokers. The western group had the highest percentage of three or more persons in the household and the shortest time since last birth, indicating that families with children dominate this group.

CONCLUSION

Our data indicate six different dietary patterns in Norway, each with different socio-demographic and lifestyle characteristics.

SPONSORSHIP

The Norwegian Cancer Society (E 04038/006).

The relation between alcohol intake and physical activity and the fatty acids 14 : 0, 15 : 0 and 17 : 0 in serum phospholipids and adipose tissue used as markers for dairy fat intake

The relative contents of the fatty acids 14 : 0, 15 : 0 and 17 : 0 in serum and adipose tissue may be used as biological markers of dairy fat intake. However, the determinants of these fatty acids are not fully understood. This study investigates the relationship between these fatty acids and the intake of macronutrients and physical activity in a cross-sectional study of 301 healthy men aged 61-64 years. Dietary intake was assessed using a pre-coded 7 d food record, and physical activity during the previous year was recorded in an interview. Under-reporters of energy intake were identified by the Goldberg cut-off. Fatty acid composition was determined in serum phospholipids (PL) and subcutaneous adipose tissue (AT) from the upper buttock. The relative content of each of 14 : 0, 15 : 0 and 17 : 0 in PL and AT was positively associated with the intake of dairy fat. In addition, all three fatty acids were inversely correlated with alcohol intake, R ranging from -0.28 to -0.53 (P<0.001). The results were not markedly affected when under-reporters (n 88) were excluded from the analyses. In both PL and AT, the relative content of the fatty acids was approximately 5% higher in a group of high physical activity compared with a group of low physical activity, although significant trends were only seen for 14 : 0 in PL and 17 : 0 in AT. The findings suggest that adjustments should be made for alcohol intake when the fatty acids 14 : 0, 15 : 0 and 17 : 0 are applied as markers for dairy fat intake.

Associations between the intake of dairy fat and calcium and abdominal obesity

OBJECTIVE

This study evaluates the association between abdominal obesity and the intake of dairy fat and calcium using information from dietary data and the relative content of the fatty acids 14:0, 15:0, and 17 : 0 in serum phospholipids (PL) and adipose tissue (AT), which are suggested biological markers for dairy fat intake. This study also explores how the associations were affected when under-reporters (URs) were separated from the analyses.

DESIGN

Cross-sectional study.

SUBJECTS

In all, 301 healthy 63-y-old men with different degrees of fasting-insulin concentrations.

METHODS

Sagittal abdominal obesity (SAD), dietary intake assessed by a 7-day food registration, and the fatty acid composition in serum PL and AT were measured. URs (n=88) and non-under-reporters (non-URs, n=213) were identified by Goldberg's equation, which compares energy intake with energy expenditure, both expressed as multiples of the basal metabolic rate.

RESULTS

The intake of dairy fat, expressed as g/100 g fat, was inversely correlated with SAD; however, this association was only observed in the URs (r=-0.36, P=0.001) and not in the non-URs (r=-0.04, P=0.59). The intake of calcium was inversely correlated with SAD in both groups, although the association was weaker in the non-URs. The intake of dairy fat was related to the relative content of the fatty acids 14:0, 15:0, and 17 : 0 in serum PL and AT (r ranging between 0.32 and 0.55). When these fatty acids were correlated to SAD, inverse associations were seen except for 14:0 in PL (r ranging between -0.17 and -0.29.

CONCLUSION

If there is a true inverse association between the intake of dairy fat and SAD, it remains to explain why this association was not seen in the non-URs. The data gave some indications of an inverse association between SAD and the intake of calcium. The diverse findings observed when the URs and non-URs were separated highlight the question of how to use and interpret dietary data in URs when diet-disease relationships are investigated.

Adjustments to improve the estimation of usual dietary intake distributions in the population

We reexamined the current practice in estimating the distribution of usual dietary nutrient intakes from population surveys when using self-report dietary instruments, particularly the 24-h recall (24HR), in light of the new data from the Observing Protein and Energy Nutrition Study. In this study, reference biomarkers for energy (doubly labeled water) and protein [urinary nitrogen (UN)], together with multiple FFQs and 24HRs, were administered to 484 healthy volunteers. By using the reference biomarkers to estimate the distributions for energy and protein, the data confirmed previous reports that FFQs generally do not give an accurate impression of the distribution of usual dietary intake. The traditional method applied to 24HRs performed poorly because of underestimating the mean and overestimating the SD of the usual energy and protein intake distributions, and, although the National Research Council and the Iowa State University methods generally give better estimates of the shape of the distribution, they did not improve the estimates of the mean (10-15% underestimation for energy and 6-7% underestimation for protein). Results for urinary potassium, a putative biomarker for potassium intake, and reported potassium intake did not display this underestimation and may reflect either differential underreporting of foods or inadequacy of the potassium biomarker. A large controlled feeding study is required to validate conclusively the potassium biomarker. For energy intake, adjusting its 24HR-based distribution by using the UN biomarker appeared to capture the usual intake distribution quite accurately. Incorporating UN assessments into nutritional surveys, therefore, deserves serious consideration.

Psychosocial predictors of energy underreporting in a large doubly labeled water study

BACKGROUND

Underreporting of energy intake is associated with self-reported diet measures and appears to be selective according to personal characteristics. Doubly labeled water is an unbiased reference biomarker for energy intake that may be used to assess underreporting.

OBJECTIVE

Our objective was to determine which factors are associated with underreporting of energy intake on food-frequency questionnaires (FFQs) and 24-h dietary recalls (24HRs).

DESIGN

The study participants were 484 men and women aged 40-69 y who resided in Montgomery County, MD. Using the doubly labeled water method to measure total energy expenditure, we considered numerous psychosocial, lifestyle, and sociodemographic factors in multiple logistic regression models for prediction of the probability of underreporting on the FFQ and 24HR.

RESULTS

In the FFQ models, fear of negative evaluation, weight-loss history, and percentage of energy from fat were the best predictors of underreporting in women (R(2) = 0.09); body mass index, comparison of activity level with that of others of the same sex and age, and eating frequency were the best predictors in men (R(2) = 0.10). In the 24HR models, social desirability, fear of negative evaluation, body mass index, percentage of energy from fat, usual activity, and variability in number of meals per day were the best predictors of underreporting in women (R(2) = 0.22); social desirability, dietary restraint, body mass index, eating frequency, dieting history, and education were the best predictors in men (R(2) = 0.25).

CONCLUSION

Although the final models were significantly related to underreporting on both the FFQ and the 24HR, the amount of variation explained by these models was relatively low, especially for the FFQ.

Assessment of the influence of energy under-reporting on intake estimates of four food additives

Under-reporting has been identified as an important source of uncertainty in food chemical exposure assessments. The objective of the present study was to assess the influence of under-reporting on food additive intake estimates. Dietary survey data were derived from the North-South Ireland Food Consumption Survey (2001). Data from the Republic of Ireland (n = 958) were used. Energy under-reporters were identified using a ratio of energy intakes to estimated basal metabolic rate. First, food categories (n = 26) included in an assessment of exposure of four food additives were created and patterns of food intakes (i.e. likelihood of consumption, frequency of consumption and reported portion size) between acceptable and under-reporters compared. Second, for each food additive, deterministic intake estimates for the total sample (i.e. acceptable and under-reporters), under-reporters and acceptable reporters were calculated and compared. Differential reporting of the majority of food categories between acceptable and under-reporters was recorded. Under-reporters were less likely to record the consumption of a given food and more likely to under-report the frequency of consumption and portion size compared with acceptable reporters. Food additive intake estimates amongst acceptable reporters were higher than corresponding intake estimates amongst the total sample of reporters and amongst under-reporters. With the exception of one food additive (erythrosine), ratios of upper percentile additive intakes amongst acceptable reporters to corresponding intake estimates amongst the total sample of reporters did not exceed 1.06 when results were expressed as total population or consumer-only intakes. Findings illustrated that energy under-reporting does not materially influence estimates of food additive exposure based on the four food additives studied. However, a number of situations were identified where the under-reporting might exert a more significant impact on resulting exposure estimates.

Digital photography: a new method for estimating food intake in cafeteria settings

OBJECTIVE

The primary objective of this study was to test the comparability of digital photography and visual estimation procedures for estimating food intake.

RESEARCH METHODS AND PROCEDURES

The study sample included 71 breakfast meals and 59 lunch meals eaten in a university cafeteria during a single day. A total of 66 different foods were employed as test foods that could be selected by the students. Food selections and plate waste, as estimated by digital photography and visual estimation, were compared. For digital photography, three observers independently estimated portion sizes of each food item based upon digital photographs. One observer estimated portion sizes in the cafeteria setting, using visual estimation, a method that has been validated in other studies.

RESULTS

To test the accuracy of the two procedures for measuring food intake, the estimates of food weights derived from both procedures were compared using Bland-Altman regression. In comparison to visual estimation, the digital photography method yielded comparable estimates of food selections, plate waste, and total food intake for seven of nine comparisons. The two methods of estimating food portions yielded comparable results for most (78%) types of foods. The two methods also yielded similar variability.

DISCUSSION

These findings suggest that the digital photography method is an alternative to the traditional method of estimating food intake via direct observation.

Subnotificação da ingestão energética na avaliação do consumo alimentar

Informações válidas sobre o consumo de energia e nutrientes são um pré-requisito em muitas pesquisas de nutrição humana, principalmente nos estudos epidemiológicos sobre dieta e saúde. Até o advento da água duplamente marcada, não era possível validar as avaliações do consumo energético de forma externa e independente. Este marcador demonstrou a existência de significativa subnotificação da ingestão energética. Esta pesquisa objetiva discutir os principais aspectos relacionados a tal fenômeno: prevalência, determinantes, especificidade de nutrientes e formas de controle. O sub-relato parece estar associado à obesidade e a características psicossociais, como a restrição dietética e o desejo de ajuste social. Todos os métodos de avaliação do consumo possuem erros inerentes, sendo portanto suscetíveis à sub ou superestimação (menos comum). O sub-relato demonstra atingir predominantemente alimentos específicos, ricos em lipídeos e carboidratos, o que insere grande viés nas inferências baseadas em levantamentos do consumo alimentar. Este artigo também discute como controlar tal erro e recomenda que as estimativas do consumo energético sejam confrontadas com o gasto energético, a fim de detectar a subnotificação.

Comparison of digital photography to weighed and visual estimation of portion sizes

OBJECTIVE

The primary goal was to test the validity of digital photography for measuring food portion sizes compared with weighed foods and with direct visual estimation.

SAMPLES

A total of 60 test meals consisting of 10 different portion sizes from six different university cafeteria menus were prepared and weighed.

DESIGN

Food selections and plate waste, as estimated by digital photography and direct visual estimation, were compared with weighed foods. For each method, three observers independently estimated portion sizes of each food. Observers expressed the portion sizes as a percentage of a standard serving. These percentages were multiplied by the weight of the standard portion to yield estimated weights. Statistical analyses To test validity, the estimates of food weights derived from both methods were compared with weighed foods using correlations and were compared with each other using Bland-Altman regression analysis.

RESULTS

For the digital photography and direct visual estimation methods, estimates of the portion sizes for food selections, plate waste, and food intake were highly correlated with weighed foods. Both methods tended to yield small overestimates or underestimates. Bland-Altman regression found the two estimation methods to yield comparable results (bias less than 1.5 g).

APPLICATIONS/CONCLUSIONS

These findings support the validity of the digital photography method for measuring portion sizes. Digital photography may be most useful for measuring food intake in settings that allow for the direct observation of food selections and plate waste but require minimum disruption of the eating environment, and allow unhurried estimates of portion sizes.

Associations between diet and the metabolic syndrome vary with the validity of dietary intake data

BACKGROUND

Underreporting is a common problem in dietary surveys. Few studies have shown the implication of this when investigating diet-disease relations.

OBJECTIVE

We investigated how underreporting affects the associations between dietary factors and the metabolic syndrome.

DESIGN

Dietary intake measured with a 7-d food record, fasting insulin concentrations, and other variables of the metabolic syndrome were assessed in a cross-sectional study of 301 healthy men aged 63 y. Biological markers for intakes of protein, sodium, and potassium were measured in 24-h urine samples. Underreporters (URs, n = 88) were identified by Goldberg's equation, which compares energy intake with energy expenditure, both expressed as multiples of the basal metabolic rate. Physical activity level was estimated, and individual cutoffs were calculated.

RESULTS

The URs had higher nutrient and food densities in their diet than did the non-URs, which suggested that they followed a healthier diet. The URs had a higher prevalence of the metabolic syndrome than did the non-URs (18% and 9%, respectively; P = 0.029). The biological markers confirmed a low validity of the dietary data in the URs. The correlations between fasting insulin concentrations, a central component of the metabolic syndrome, and the intakes of polyunsaturated fats, n-6 fats, and fat from milk products were stronger in the URs than in the non-URs, which indicates that inaccurate data can introduce spurious associations.

CONCLUSION

The association between diet and fasting insulin differed between URs and non-URs in this study of 301 healthy men aged 63 y. If URs are not identified and excluded or treated separately in studies in nutritional epidemiology, spurious diet-disease relations may be reported.

Gender differences in dietary intakes, anthropometrical measurements and biochemical indices in an urban adult population: the Tehran Lipid and Glucose Study

BACKGROUND AND AIM

In order to investigate gender differences in health indices, dietary intakes and obesity in urban Iranian adults, we considered a sub-sample of the adult population of the Tehran Lipid and Glucose Study.

METHODS AND RESULTS

The randomly selected sub-sample consisted of 483 subjects aged 25-50 years (229 men and 254 women) and 153 aged more than 50 years (81 men and 72 women). Their anthropometrical variables were recorded, and their body mass index (BMI) and waist/hip ratio were calculated. Dietary intake was assessed by means of two-day dietary recall and the completion of dietary habit questionnaires during face-to-face interviews. Underreporting was defined as a ratio of energy intake (EI)/basal metabolic rate (BMR) < 1.27. The mean BMI of the women in both age groups was significantly higher than that of the men (p < 0.05). Central obesity was more frequent in the women and among older subjects. The women had higher plasma concentrations of high-density lipoprotein cholesterol, but lower levels of total and low-density lipoprotein cholesterol. Underreporting of EI was more frequent in the women than the men: 34.0% vs 15.4% in the younger group, and 40.3% vs 17.3% in the older group (p < 0.01). There were major gender differences in the mean daily intakes of energy, protein, carbohydrate, fat, fibre, cholesterol, iron, calcium and phosphorus. A higher proportion of women met the cholesterol intake guidelines. Data from the dietary habit questionnaires showed that more men than women usually sprinkle salt on their food.

CONCLUSIONS

The results of this study partially support the hypothesis of gender differences in dietary intakes, and the prevalence of obesity and some health-related indices, and suggest the need for gender-specific, targeted nutrition messages and behavioural interventions in developing prevention strategies for cardiovascular risk factors.

Markers of the validity of reported energy intake

Energy intake (EI) is the foundation of the diet, because all other nutrients must be provided within the quantity of food needed to fulfill the energy requirement. Thus if total EI is underestimated, it is probable that the intakes of other nutrients are also underestimated. Under conditions of weight stability, EI equals energy expenditure (EE). Because at the group level weight may be regarded as stable in the timescale of a dietary assessment, the validity of reported EI can be evaluated by comparing it with either measured EE or an estimate of the energy requirement of the population. This paper provides the first comprehensive review of studies in which EI was reported and EE was measured using the doubly labeled water technique. These conclusively demonstrate widespread bias to the underestimation of EI. Because energy requirements of populations or individuals can be conveniently expressed as multiples of the basal metabolic rate (BMR), EE:BMR, reported EI may also be expressed as EI:BMR for comparison. Values of EI:BMR falling below the 95% confidence limit of agreement between these two measures signify the presence of underreporting. A formula for calculating the lower 95% confidence limit was proposed by Goldberg et al. (the Goldberg cutoff). It has been used by numerous authors to identify individual underreporters in different dietary databases to explore the variables associated with underreporting. These studies are also comprehensively reviewed. They explore the characteristics of underreporters and the biases in estimating nutrient intake and in describing meal patterns associated with underreporting. This review also examines some of the problems for the interpretation of data introduced by underreporting and particularly by variable underreporting across subjects. Future directions for research are identified.

An evaluation of the sensitivity and specificity of energy expenditure measured by heart rate and the Goldberg cut-off for energy intake: basal metabolic rate for identifying mis-reporting of energy intake by adults and children: a retrospective analysis

OBJECTIVE

To identify adults and children as under- (UR), acceptable (AR), or over-reporters (OR) of energy intake (EI) using energy expenditure measured by doubly labelled water (DLW) (EE(DLW)), and to use this as a reference to determine the sensitivity and specificity of (i) EE measured by heart rate (EE(HR)), and (ii) the Goldberg cut-off technique for classifying subjects into the same categories.

DESIGN

Retrospective analysis of a dataset comprising concurrent measurements of EE(DLW), EE(HR), basal metabolic rate (BMR), and EI by weighed record (EI(WR)) on 14 adults and 36 children. EI by diet history (EI(DH)) was also measured in the children only. EI(WR):EE(DLW) provided the reference definition of subjects as UR, AR or OR. Three strategies for classifying mis-reporters based on EE(HR) and Goldberg cut-offs were then explored. Sensitivity and specificity were calculated respectively as the proportion of UR and non-UR correctly identified.

RESULTS

Approximately 80% of all subjects were AR. For EI(WR) and EI(DH) respectively, the sensitivity of EE(HR) was 0.50 and 1.00, and specificity was 0.98 and 1.00. Although designating subjects as having low, medium or high activity levels (EE(HR):BMR(meas)) and calculating cut-offs based on appropriate WHO physical activity level PALs did not change sensitivity, specificity dropped to 0.98 (EI(WR)) and 0.97 (EI(DH)). Cut-offs based on a PAL of 1.55 reduced sensitivity to 0.33 (EI(WR)) and 0.00 (EI(DH)), but specificity remained unchanged. The sensitivity of all cut-offs based on physical activity level (PALs) for EI(WR) was 0.50 (adults) and 0.25 (children).

CONCLUSIONS

If the precision of EE(HR) was improved, it may be useful for identifying mis-reporters of EI.

Estimation of usual intakes: What We Eat in America-NHANES

Usual intakes of nutrients are reliable indicators for making associations between diet and health or disease risks. Estimates of consumption of specific foods and food groups are also important for evaluating the progress in meeting key objectives in such national public health initiatives as Healthy People 2010. Reliable and valid estimates of intakes of particular foods, food ingredients, dietary supplements and other bioactive substances are also needed for dietary assessment and regulatory purposes. The ability to generate useful estimates of these constituents often requires much larger sample sizes than are needed for estimating nutrient intakes. Statistical methods recommended by the National Academy of Sciences are described that provide estimates of distributions of usual nutrient intakes and permit dietary assessment and planning at the population level. Statistical and modeling approaches for estimating intakes of foods, dietary supplements and other bioactive substances are also summarized. Based on the deliberations of discussion groups consisting of members of key stakeholder groups involved in the planning, implementation and utilization of national survey data, a high priority was placed on the need for more research to determine the best approaches for applying these methods to dietary data in the integrated What We Eat in America-National Health and Nutrition Examination Survey (NHANES).

Socio-economic status, dietary intake and 10 y trends: the Dutch National Food Consumption Survey

OBJECTIVE

To study differences in dietary intake between adults with different socioeconomic status (SES) and trends over time.

DESIGN

Cross-sectional study based on data of three Dutch National Food Consumption Surveys (DNFCS-1 1987/88; DNFCS-2 1992; DNFCS-3 1997/98), obtained from a panel by a stratified probability sample of the non-institutionalized Dutch population.

SUBJECTS

A total of 6008 men and 6957 women aged 19 y and over.

METHODS

Dietary intake was assessed with a 2 day dietary record. Background information was obtained by structured questionnaire. Sociodemographic variables were available from panel information. SES, based on educational level, occupation and occupational position was categorized into (very) low, middle and high. Analysis of variance with age as covariable was used to explore the effects of SES on dietary intake and anthropometry. Statistical tests for trend were carried out with models in which week-weekend-day effects and an interaction term of time with SES were also included.

RESULTS

The prevalence of obesity and skipping of breakfast was higher among people with a low SES. In all three surveys, subjects in the (very) low SES group reported having a higher consumption of potatoes, meat and meat products, visible fats, coffee and soft drinks (men only). Subjects with a high SES reported consuming more vegetables, cheese and alcohol. As regards nutrients, in all surveys a higher SES was associated with higher intake of vegetable protein, dietary fibre and most micronutrients. A higher SES was also associated with a lower fat intake but the differences between social classes were rather small and not consistent when the contribution of alcohol to energy intake was taken into account.

CONCLUSION

In general, dietary intake among subjects in higher SES groups tended to be closer to the recommendations of the Netherlands Food and Nutrition Council and this phenomenon was quite stable over a period of 10 y.

Procedures for screening out inaccurate reports of dietary energy intake

OBJECTIVE

To review existing methods and illustrate the use of a new, simple method for identifying inaccurate reports of dietary energy intake (rEI).

DESIGN

Comparison of rEI with energy requirements estimated by using total energy expenditure predicted (pTEE) from age, weight, height and sex using a previously published equation. Propagation of error calculations was performed and cut-offs for excluding rEI at plus or minus two standard deviations (+/-2 SD) and +/-1 SD for the agreement between rEI and pTEE were established.

SETTING

Dietary survey in a US national cohort: the Continuing Survey of Food Intakes by Individuals (CSFII), 1994-96.

SUBJECTS

Men and non-pregnant, non-lactating women aged 21-45 years in the CSFII who provided two multiple-pass 24-hour recalls, height and weight (n = 3755).

RESULTS

Average rEI was 77% of pTEE in men, and 64% of pTEE in women. Calculated cut-offs were rEI <40% or >160% of pTEE (+/-2 SD) and <70% or >130% of pTEE (+/-1 SD), respectively. Use of only the +/-1 SD cut-offs, not the +/-2 SD cut-offs, resulted in a relationship between rEI and body weight similar to what was expected (based on an independently calculated relationship between rEI and measured TEE). Exclusion of rEI outside either the +/-2 SD (11% of subjects) or +/-1 SD (57% of subjects) cut-offs did not affect mean reported macronutrient intakes, but did markedly affect relationships between dietary composition and body mass index.

CONCLUSIONS

When examining relationships between diet and health, use of +/-1 SD cut-offs may be preferable to +/-2 SD cut-offs for excluding inaccurate dietary reports.

A methodological report from the Malmö Diet and Cancer study: development and evaluation of altered routines in dietary data processing

BACKGROUND

In the Malmö Diet and Cancer study, information on dietary habits was obtained through a modified diet history method, combining a 7-day menu book for cooked meals and a diet questionnaire for foods with low day-to-day variation. Half way through the baseline data collection, a change of interview routines was implemented in order to reduce interview time.

METHODS

Changes concentrated on portion-size estimation and recipe coding of mixed dishes reported in the menu book. All method development and tests were carefully monitored, based on experiential knowledge, and supplemented with empirical data. A post hoc evaluation study using "real world" data compared observed means of selected dietary variables before and after the alteration of routines handling dietary data, controlling for potential confounders.

RESULTS

These tests suggested that simplified coding rules and standard portion-sizes could be used on a limited number of foods, without distortions of the group mean nutrient intakes, or the participants' ranking. The post hoc evaluation suggested that mean intakes of energy-adjusted fat were higher after the change in routines. The impact appeared greater in women than in men.

CONCLUSIONS

Future descriptive studies should consider selecting subsets assessed with either method version to avoid distortion of observed mean intakes. The impact in analytical studies may be small, because method version and diet assistant explained less than 1 percent of total variation. The distribution of cases and non-cases across method versions should be monitored.

Underreporting of energy intake is less common among pregnant women in Indonesia

OBJECTIVES

To evaluate the ratio of reported energy intake to basal metabolic rate (EI/BMR) among pregnant Indonesian women, as well as identifying risk factors for being an underreporter.

DESIGN

Longitudinal study of dietary intake, using six repeated 24-hour diet recalls each trimester. Basal metabolic rate was estimated from body weight and physical activity from occupation. The lower 95% confidence interval for plausible EI/BMR was calculated and the proportion of underreporters estimated. Risk factors for being an underreporter were assessed in multivariate logistic regression analyses.

SETTING

Purworejo District, central Java, Indonesia.

SUBJECTS

Pregnant women

RESULTS

For the three trimesters, EI/BMR ratio was and (mean+/-standard deviation), respectively. The proportion of underreporters was 29.7%, 16.2% and 17.6%. Characteristics significantly associated with underreporting in at least one trimester included high body mass index and low education.

CONCLUSIONS

Levels of underreporting were low among the pregnant Indonesian women during the second and third trimesters. The low EI/BMR ratio during the first trimester likely reflects a true low intake due to nausea, rather than underreporting. Risk factors for being an underreporter included those known from developed countries, i.e. obesity and low education.

Development, validation and utilisation of food-frequency questionnaires - a review

OBJECTIVE

The purpose of this review is to provide guidance on the development, validation and use of food-frequency questionnaires (FFQs) for different study designs. It does not include any recommendations about the most appropriate method for dietary assessment (e.g. food-frequency questionnaire versus weighed record).

METHODS

A comprehensive search of electronic databases was carried out for publications from 1980 to 1999. Findings from the review were then commented upon and added to by a group of international experts.

RESULTS

Recommendations have been developed to aid in the design, validation and use of FFQs. Specific details of each of these areas are discussed in the text.

CONCLUSIONS

FFQs are being used in a variety of ways and different study designs. There is no gold standard for directly assessing the validity of FFQs. Nevertheless, the outcome of this review should help those wishing to develop or adapt an FFQ to validate it for its intended use.

Nature of dietary reporting by adults in the third National Health and Nutrition Examination Survey, 1988-1994

OBJECTIVE

Low reporting of food intake is an acknowledged problem in dietary assessments; however, differences in food intake relative to reporting status are poorly understood. This study examined the relation of a measure of dietary reporting status with the nature of food intake reported by adults in the third National Health and Nutrition Examination Survey.

METHODS

Subjects were 6948 women and 6452 men, 20 years of age or older, with a complete and reliable 24-hour dietary recall. The ratio of reported energy intake to estimated basal energy expenditure (EI/BEE) was computed as a measure of dietary reporting status. The independent relation of EI/BEE ratio with 1) the amount, number, and energy density of nutrient-dense and low-nutrient-dense foods, 2) the number of reported eating occasions, 3) macro- and micronutrient intake and 4) serum concentrations of folate, ascorbate and carotenoids were examined using gender-specific multiple regression models.

RESULTS

The EI/BEE ratio related positively with the amount, number and energy density of both nutrient-dense and low-nutrient-dense foods, and grams of alcoholic beverages. The EI/BEE ratio was an independent negative predictor of serum folate, ascorbate and alpha-carotene concentrations confirming the underreporting of food sources of these nutrients. The relative odds of reporting < or = 30% of energy as fat or < 10% of energy as saturated fat decreased with ratio of EI/BEE; however, the odds of reporting all five food groups or meeting the recommended intake of selected micronutrients increased with EI/BEE.

CONCLUSIONS

The quantity and the quality of food intake reported in the 24-hour recall in NHANES III differed in relation to the ratio of EI/BEE.

Impact of interviewer's body mass index on underreporting energy intake in overweight and obese women

OBJECTIVE

To determine if overweight and obese women provide more accurate reports of their energy intake by 1) in-person recall with an obese interviewer, 2) in-person recall with a lean interviewer, or 3) telephone recall with an unknown interviewer.

RESEARCH METHODS AND PROCEDURES

Eighty-eight overweight and obese women participated in this study. Subjects completed one telephone-administered multiple-pass 24-hour recall (MP24R) with an unknown interviewer and were then randomly assigned to an in-person MP24R with either a lean or obese interviewer to gather reported energy intake (rEI). Basal metabolic rate (BMR) was measured using a Deltrac monitor, and physical activity (EEPA) was estimated using a Caltrac accelerometer. Therefore, estimated energy expenditure was determined by: estTEE = (BMR + EEPA) x 1.10.

RESULTS

No significant differences were found between the two in-person interview modes for subject age, weight, body mass index, percentage of body fat, total energy expenditure, rEI, and misreporting of energy intake. In-person recall data were combined for comparison with the telephone recalls. No significant difference was found between the in-person and telephone recalls for rEI and misreporting. Mean reported energy intake was significantly lower than estimated total energy expenditure for the telephone recalls and combined (lean and obese modes) in-person recalls.

CONCLUSIONS

This study found that interviewer body mass index had no impact on self-reported energy intake during an in-person MP24R, and that telephone recall data were comparable with in-person recalls. Underreporting was a widespread problem ( approximately 26%) for all modes in this sample.

Ten-year trends of dietary intake in a middle-aged French population: relationship with educational level

OBJECTIVE

To compare dietary intakes at a 10 y interval of a population aged 35-64 living in France. Trends in nutrient intake and food consumption were examined with a special emphasis on the relationships between educational level and dietary behaviour.

DESIGN

Two independent surveys conducted in 1985-1987 (S1) and 1995-1997 (S2) in the framework of the WHO MONICA project. Dietary intake was assessed with a 3-day record method and a food frequency questionnaire. The samples analysed included 416 men and 446 women for S1, 393 men and 409 women for S2.

RESULTS

A significant improvement of the quality of fat intake was observed between S1 and S2, independently of educational level, with an increase of the age adjusted P/S ratio from 0.42 to 0.50 in men (P=10(-4)) and from 0.41 to 0.50 in women (P=10(-4)), whereas the daily cholesterol intake dropped from 552.0 to 466.9 mg and from 447.2 to 384.6 mg in men and women, respectively (P=10(-4)). These variations were associated with a decrease in the consumption of high-fat foods and an increase in that of low-fat products (poultry, low-fat dairy foods, fish) in all educational classes. By contrast, the consumption of fruit and vegetables, which was highly associated with educational level, varied little over time.

CONCLUSIONS

Our results indicate slight improvement in fat quality, independently of educational level, while fruit and vegetable intake, which appeared more dependent on educational level, was only poorly modified over the 10 y interval.

Relation between mothers' child-feeding practices and children's adiposity

BACKGROUND

The prevalence of obesity in American children is currently estimated to be 25%. Poor nutritional habits during childhood have been directly related to pediatric obesity.

OBJECTIVE

Our objective was to evaluate the relation between mothers' child-feeding practices and children's adiposity in a sample of boys and girls from 2 ethnic groups.

DESIGN

A total of 74 white (25 boys and 49 girls) and 46 African American (22 boys and 24 girls) children ( plus minus SD age: 11 plus minus 1.7 y) and their mothers participated in this study. The children's body composition was assessed by dual-energy X-ray absorptiometry. The mothers' child-feeding practices were assessed with the Child Feeding Questionnaire. Dietary intake data were based on three 24-h dietary recalls conducted by use of the multiple-pass technique.

RESULTS

Two subscales of the Child Feeding Questionnaire, pressure to eat and concern for child's weight, explained 15% of the variance in total fat mass in both African American and white boys and girls (P < 0.001) after correction for total lean mass and energy intake (which explained 5% of the variance in total fat mass). Ethnicity, sex, and socioeconomic status did not contribute significantly to variance in total fat mass.

CONCLUSIONS

Child-feeding practices are key behavioral variables that explain more of the variance in total fat mass than does energy intake in a biethnic population of boys and girls. These findings have important implications for the prevention of obesity in children because they suggest that prevention programs need to focus on the feeding behaviors of parents in addition to the macronutrient and energy intakes of children.

Underreporting of energy intake in an elderly German population

OBJECTIVES

Within the longitudinal study on nutrition and health status in an aging population in Giessen, Germany (GISELA), the underreporters of energy intake (EI) were identified and characterized.

METHODS

EI was assessed in 238 female and 105 male participants of the GISELA study (age range = 60-89 y) by means of a 3-day estimated dietary record developed especially for this study. Resting metabolic rate (RMR) was measured by indirect calorimetry after an overnight fast. EI was expressed as a multiple of RMR and subjects with an EI:RMR ratio below 1.073 were classified as underreporters.

RESULTS

Mean EI:RMR was 1.62 +/- 0.46 in females and 1.53 +/- 0.46 in males; 7.6% of the females and 16.2% of the males were identified as underreporters. They showed lower levels of education and significantly greater body weight, body mass index, and fat mass than the adequate reporters. Further, underreporters stated more often than adequate reporters that they want to lose weight. Except for beta-carotene in males, reported nutrient intakes were significantly lower in underreporters than in adequate reporters. Carbohydrate and fat intake in both sexes, protein intake in females calculated as a percentage of EI, and vitamin and mineral densities were not affected by underreporting.

CONCLUSIONS

The results indicate that underreporting of EI is related to a low educational level and greater body weight, body mass index, and fat mass and affects all nutrients. These findings should be considered when the association between nutrition and health status is investigated in the elderly.

Alcohol drinkers overreport their energy intake in the BIRNH study: evaluation by 24-hour urinary excretion of cations. Belgian Interuniversity Research on Nutrition and Health

OBJECTIVE

Alcohol drinkers are generally considered to underreport their alcohol intake, but little is known about whether they correctly report their energy intake (EI). We assessed the validity of the reported energy intake of alcohol drinkers using the 24-hour urinary (U) excretion of potassium (K) and sodium (Na) as biomarkers.

METHODS

A total of 2,124 men and 1,998 women 25 to 74 years of age with a 24-hour urine collection, a random sample of the Belgian Interuniversity Research on Nutrition and Health (BIRNH). were studied. Dietary intake (D), including alcohol consumption, was assessed by a one-day food record. Basal metabolic rate (BMR) was predicted from age, gender and weight. As a measure for the degree of reporting error, D-K/U-K, D-Na/U-Na, EI/U-K, Non-alcohol EI/U-Na (NAEI/U-Na), EI/U-Na, EI/U-creatinine and EI/BMR ratios were calculated and compared among non-, moderate and heavy drinkers in both genders.

RESULTS

EI, NAEI and all seven ratios examined generally increased with the level of alcohol intake in both genders. After adjustment for age, body mass index, smoking and educational level, most ratios were significantly higher in moderate drinkers (p < 0.02 to p < 0.0001) and in heavy drinkers (all p < 0.0001) than in non-drinkers. These differences were most significant in male heavy drinkers. The exceptions were D-K/U-K, D-Na/U-Na and NAEI/U-Na in moderate and female heavy drinkers and EI/U-K in male moderate drinkers. The estimated amount of the overreporting of EI by heavy drinkers was 27.8% in men and 13.7% in women.

CONCLUSIONS

This study provides evidence that EI and NAEI obtained from the BIRNH study was overreported among alcohol drinkers, especially among male heavy drinkers. It also indicates that EI from alcohol replaced EI from food.

Underreporting of energy intake in repeated 24-hour recalls related to gender, age, weight status, day of interview, educational level, reported food intake, smoking habits and area of living

OBJECTIVE

The aims of the present study were (1) to evaluate the degree to which underreporting of energy intake by repeated 24-hour recalls was related to gender, age, weight status, day of interview, educational level, smoking habits and area of living, and (2) to compare the dietary characteristics of underreporters with those of others.

DESIGN

Cross-sectional study. Ten 24-hour recalls were performed during a one-year period.

SETTING

The Västerbotten intervention programme of cardiovascular disease and diabetes in Northern Sweden.

SUBJECTS

Ninety-four men and 99 women in four age groups: 30, 40, 50 and 60 years.

RESULTS

The prevalence of men and women with a food intake level (FIL; reported energy intake divided by estimated basal metabolic rate) below 1.2 was 44% and 47%, respectively. The youngest age group had higher FIL values than the oldest age group for both men (1.5 versus 1.1) and women (1.4 versus 1.1). The prevalence and magnitude of underreporting were directly related to body mass index (BMI; correlation coefficient: -0.47 (men) and -0.55 (women)). Smokers had a lower FIL value (1.1) than non-smokers (1.3). The nutrient density was lower for the group with high FIL values for protein and calcium and higher for fat and sucrose. The upper FIL group often had higher intake frequencies and larger portion sizes than the lower FIL group.

CONCLUSIONS

Underreporting of energy intake is prevalent when 24-hour recalls are used, but the prevalence differs between sub-groups in the population. BMI was the main predictor of underreporting but also old age and smoking seem to contribute in this aspect. Socially desirable food items were not underreported to the same extent as socially undesirable food items. The intake frequencies and portion sizes partly explained the differences in FIL.

Food and nutrient intake in a cohort of 8-month-old infants in the south-west of England in 1993

OBJECTIVE

To investigate food and nutrient intakes in 8-month-old infants.

DESIGN

Prospective study.

SETTING

Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC), south-west England.

SUBJECTS

A total of 1131 singleton Caucasian infants (82% of those invited) from a 10% random sample of ALSPAC, known as Children in Focus (CIF).

METHODS

Diet was assessed using a structured 3-day unweighed dietary record. Food and nutrient intakes were compared with intakes from the 6--9 month age group of a British infant feeding survey, which formed part of the National Diet and Nutrition Survey (NDNS). Nutrient intakes were compared with dietary reference values (DRV).

RESULTS

Intakes of energy and most nutrients were very similar between CIF and NDNS. The main difference was in the type of fat eaten resulting in a higher polyunsaturated to saturated fatty acid ratio in CIF (0.34) compared with NDNS (0.21). Other differences included the much lower calcium and iodine intakes in CIF compared with the NDNS. Differences in the proportion of consumers of formula and cow's milk accounted for most of the nutrient differences. Energy intakes were similar to the estimated average requirements (EAR), however, breastfed infants were slightly below and non-breastfed were slightly above the EAR. Mean intakes of zinc and vitamin D were below the Reference Nutrient Intakes.

CONCLUSIONS

The diets of 8-month-old infants in this study were adequate in most nutrients. Breastfed infants had slightly lower energy intakes than non-breastfed infants.

Does social deprivation in 1, 2, 3 and 4-year-old Scottish infants influence the frequency isolation of caries-associated micro-organisms?

OBJECTIVES

The aim of this study was to determine if there are associations between the level of social deprivation/affluence and the frequency isolation of caries-associated micro-organisms (Streptococcus mutans, Streptococcus sobrinus, lactobacilli and yeasts) in a large cohort of infants examined annually from 1 to 4 years of age.

METHODS

DEPCAT was used to measure the socio-economic status of all consented infants (n=1099--1392) born in Dundee during a 1 year period (total n=1974). Caries-associated micro-organisms were cultured from saliva when the infants were 1, 2, 3 and 4 years of age. Standardised dental examinations were also carried out annually. Log linear analysis, which controlled for caries, was used to look for associations between DEPCAT and the isolation frequency of caries-associated micro-organisms.

RESULTS

When controlling for caries, there was an association between DEPCAT and the isolation frequency of yeasts when the infants were 1 and 2 but not when 3 and 4 years old, whereas lactobacilli were associated only when the infants were 3 and 4 years old. Correlations between S. mutans and social deprivation were usually dependent on the caries status of the infants.

CONCLUSIONS

The relationship between social deprivation and the isolation frequencies of caries-associated micro-organisms is complex with lactobacilli developing an association when the infants were 3 and 4 years old in contrast to yeasts which were only associated when the infants were 1 and 2 years old. Streptococcus mutans was associated with social deprivation when the infants were 2 years old and older, but dependent on caries status in the 3 and 4 year olds.

Identification of groups who report similar patterns of diet among a representative national sample of British adults aged 65 years of age or more

OBJECTIVES

Using a national representative sample to identify groups within the UK male and female population over 65 years who report similar patterns of diet.

DESIGN

National representative dietary survey, using 4-day weighed dietary records of men and women aged over 65 years old and living in private households in Great Britain in 1994-1995. Cluster analysis was used to aggregate individuals into diet groups.

SETTING

United Kingdom.

SUBJECTS

558 women and 539 men.

MAIN OUTCOME MEASURES

Consumption of predefined food groups, nutrient intakes, socio-economic, demographic and behavioural characteristics.

RESULTS

Three large clusters comprising 86% of the male population and three large clusters comprising 83% of the female population were identified. Among men, the most prevalent cluster was a "mixed diet" with elements from a traditional diet and some elements from a healthy diet (48% of the male population); the second was a "healthy diet" (21% of the male population); and the third was a "traditional diet high in alcohol" (17% of the male population). Among women, the most prevalent diet was a "sweet traditional diet" (33% of the female population); the second was a "healthy diet" (32% of the female population); and the last was a "mixed diet" with elements of the traditional diet and the healthy diet (18% of the female population). There were important differences in average nutrient intakes, socio-demographic and behavioural characteristics across these diet clusters.

CONCLUSIONS

Cluster analysis identified three diet groups among men and three among women. These differed not only in terms of reported dietary intake, but also with respect to their nutrient content, social and behavioural profile. The groups identified could provide a useful basis for health promotion based upon the diet clusters.

Are the proposed limits of energy intake:basal metabolic rate and dietary nitrogen:urinary nitrogen ratios suitable for validation of food intake?

The validity of 7 d weighed records of diet obtained for pre-menopausal Mexican women was assessed by two independent methods: the energy intake:BMR (EI:BMR) and the dietary N:urinary N (DN:UN). For the latter, complete urine collections are required and completeness was assessed from measurements of para-aminobenzoic acid (PABA) excretion. There were forty-six adult female subjects in the study, thirty-four were from Mexico City and twelve were from a rural population in the Central Highlands, Mexico. However, data were rejected from five urban women for whom the PABA excretion data suggested incomplete urine collection on four or more days. BMR was measured with Oxylog portable O2 consumption meters, and physical activity level was assessed from a self-completed activity diary. An approximate relationship between the EI:BMR ratio and the DN:UN ratio suggested that the rejection limits on the EI:BMR ratio recommended by are wider than the limits on the DN:UN ratio recommended by. Using the recommended cut-off points for EI:BMR but wider limits for DN:UN, twenty-one and twenty-five women respectively had acceptable intake records by the two methods, and sixteen of them by both methods. In conclusion the modification of the DN:UN limits to 0.92 and 1.70 to set acceptable intake values makes the use of measurements of N and energy balance comparable. Urine values with PABA recoveries greater than should be rejected, as should UN values validated by less than 3 d.

Gender differences in the relation between food cravings and mood in an adult community: Results from the fleurbaix laventie ville santé study

OBJECTIVE

The aim of this survey was to study food cravings and its indulgence in community adults (538 women and 506 men) and to compare nutritional parameters, weight preoccupations, and weight history between cravers and noncravers.

METHOD

Cravers experienced a strong urge to eat specific foods more than once a week during the past 6 months. Food intake was estimated by a 3-day food record.

RESULTS

28% of women and 13% of men were food cravers. Cravers, especially women, were more frequently concerned about their weight than noncravers. Energy intake during snacks was higher in cravers. Less than 40% of cravers reported being hungry when they experienced cravings. Women cravers indulged their cravings as often as men. They reported more frequently negative feelings, whereas men reported more frequently positive feelings.

DISCUSSION

This study shows that food craving episodes are strongly associated with mood but in a different way in women and men.

Dietary patterns among a national random sample of British adults

STUDY OBJECTIVES

To identify groups within the UK male and female population who report similar patterns of diet.

DESIGN

National representative dietary survey, using seven day weighed dietary records, of men and women aged 16-64 years living in private households in Great Britain in 1986-7. Cluster analysis was used to aggregate participants into diet groups.

SETTING

Great Britain.

PARTICIPANTS

1087 men and 1110 women.

RESULTS

93% of men and 86% of women fell into one of four distinct diet groups. Among men the most prevalent diet group was "beer and convenience food" (34% of the male population); second was "traditional British diet" (18%); third was "healthier but sweet diet" (17.5%) and fourth was "healthier diet " (17%). Among women, the most prevalent diet group was " traditional British diet" (32%); second, was "healthy cosmopolitan diet" (25%); third was a "convenience food diet" (21%); and fourth was "healthier but sweet diet" (15%). There were important differences in nutrient profile, sociodemographic and behavioural characteristics between diet groups.

CONCLUSIONS

Cluster analysis identified four diet groups among men and four among women, which differed not only in terms of reported dietary intakes, but also with respect to nutrient, social and behavioural profiles. The groups identified could provide a useful basis for development, monitoring and targeting of public health nutrition policy in the UK.

Biased over- or under-reporting is characteristic of individuals whether over time or by different assessment methods

Seven studies with repeated measurements of energy intake and/or nitrogen intake were examined to determine whether misreporting is characteristic of some persons or occurs randomly. Four of the studies were validated by doubly labeled water measurements of energy expenditure. Reporting validity was expressed as the ratio of energy intake to energy expenditure. Ratios were consistently below the expected value of 1.0 for some subjects and consistently above 1.0 for others, indicating characteristic reporting validity within subjects. Two year-long studies provided 4 to 12 measurements and a total number of days sufficient to measure individual habitual intake. Subjects mean energy intake to basal metabolic rate (BMR) ratios were < 1.35 in 45% and 47% and < 1.35 at every measurement in 25% of subjects. This indicated persistent underreporting over time, because 1.35 x BMR is the minimum energy expenditure compatible with a normally active lifestyle. Three of the studies used more than 1 assessment method (validated by doubly labeled water and/or urinary nitrogen excretion). There was a tendency for persons determined to be underreporters by 1 method to be also underreporters when tested by other methods. We conclude that biased over- or underreporting is characteristic of some persons. Thus, repeat measurements do not necessarily provide valid measures of individual intake, extreme intakes may reflect under- and overreporting rather than true low or high intakes, and subjects most prone to reporting bias may be repeatedly misclassified in quantiles of the distribution. This presents a challenge to dietitians nutritionists, and statisticians both for the design of surveys and the handling of flawed data.

Does energy intake underreporting involve all kinds of food or only specific food items? Results from the Fleurbaix Laventie Ville Santé (FLVS) study

OBJECTIVE

To determine if energy intake underreporting concerns all major food groups or if it occurs for specific food groups only.

DESIGN

Cross-sectional study on dietary habits and food consumption.

SUBJECTS

Five-hundred and four women and 529 men, aged between 25 and 55y participating in the Fleurbaix Laventie Ville Sante study.

MEASUREMENTS

A nutritional survey was conducted between March and June 1993 using a 3-day food record. Reported weight and height were used to estimate body mass index and basal metabolic rate. Underreporters were defined as subjects whose ratio of mean energy intake to basal metabolic rate was lower than 1.05. Food consumption was compared between underreporters and non-underreporters.

RESULTS

Energy percentage of fat and carbohydrate were lower in underreporters than in non-underreporters in contrast to the energy percentage of protein. This was due to the fact that food items rich in fat and/or carbohydrates (such as butter, French fries, sugars and confectionery, cakes and pastries) were reported to be less frequently eaten and/or in smaller quantities in underreporters compared to non-underreporters.

CONCLUSION

Although this study presents some limitations, like the use of reported weight and a standard value for physical activity, it shows that reported foods differed, quantitatively and qualitatively, between severe underreporters and non-underreporters. Underreporting of food intake does not result from a systematical underestimation of portion sizes for all food items, but seems to concern specific food items which are generally considered 'bad for health'.

Influence of body composition on the accuracy of reported energy intake in children

OBJECTIVE

Mis-reporting dietary intake is a substantial barrier to understanding the role of dietary behavior in disease. Work with adults indicates that heavier individuals under-report dietary intake and that under-reporting may be macronutrient-specific. Whether weight status and macronutrient intake influence the accuracy of dietary reports among children, however, is less clear. This research evaluated children's dietary reporting accuracy as a function of their relative weight, body composition, and macronutrient intake.

RESEARCH METHODS AND PROCEDURES

Participants included 146 4- to 11-year-old children. Reported energy intake was determined by interviewing children in the presence of parents, using three multiple pass, 24-hour recalls. Children were classified as having had an under-reported, accurately reported, or over-reported dietary intake relative to total energy expenditure, as measured by doubly labeled water. Reporting accuracy was examined as a function of children's body weight, body composition (using dual energy x-ray absorptiometry), and macronutrient intake.

RESULTS

Average reported intake was, on average, 14% greater than children's estimated expenditure (p < 0.01). Reporting accuracy varied as a function of children's relative weight and body composition; under-reporting tended to occur among heavier children, having the highest body fat content (p < 0.0001) and relative weight (p < 0.0001).

DISCUSSION

These findings suggest that weight status influences the accuracy of dietary reports made by children and their parents. More research is needed to address possible psychological and social factors that introduce bias in reporting children's dietary data.

Consumption of energy-dense, nutrient-poor foods by adult Americans: nutritional and health implications. The third National Health and Nutrition Examination Survey, 1988-1994

BACKGROUND

Current dietary guidance recommends limiting the intake of energy-dense, nutrient-poor (EDNP) foods, but little is known about recent consumption patterns of these foods.

OBJECTIVE

The contribution of EDNP foods to the American diet and the associated nutritional and health implications were examined.

DESIGN

Data from the third National Health and Nutrition Examination Survey (n = 15611; age >/=20 y) were used. EDNP categories included visible fats, nutritive sweeteners and sweetened beverages, desserts, and snacks. The potential independent associations of EDNP food intake with intakes of energy, macronutrients, micronutrients, and serum vitamin, lipid, and carotenoid profiles were examined with linear and logistic regression procedures.

RESULTS

EDNP foods supplied approximately 27% of energy intake; alcohol provided an additional 4%. The relative odds of consuming foods from all 5 food groups and of meeting the recommended dietary allowance or daily reference intake for protein and several micronutrients decreased with increasing EDNP food intake (P: < 0.0001). Energy intake and percentage of energy from fat were positively related to EDNP intake. Serum concentrations of vitamins A, E, C, and B-12; folate; several carotenoids; and HDL cholesterol were inversely related (P: </= 0. 0005) whereas serum homocysteine concentration was positively related (P: = 0.02) to EDNP food intake.

CONCLUSIONS

The results suggest that EDNP foods were consumed at the expense of nutrient-dense foods, resulting in 1) increased risk of high energy intake, 2) marginal micronutrient intake, 3) poor compliance with nutrient- and food group-related dietary guidance, and 4) low serum concentrations of vitamins and carotenoids.

Types of fat intake and body mass index in a Mediterranean country

BACKGROUND

Although the fatty acid fractions provide similar metabolizable energy, the type of dietary fat consumed could be relevant to the development of obesity.

OBJECTIVE

To investigate the relationship between body mass index (BMI), obesity and the consumption of different types of fat and olive oil in a Mediterranean country with high prevalence of obesity, and high intake of monounsaturated fatty acids (MUFA) and olive oil.

SUBJECTS

The study was carried out in Spain among 23 289 women and 14 374 men, aged 29-69 years, who were participants of a large European prospective cohort.

METHODS

: Information on usual food intake was collected by interviewers by means of a dietary history questionnaire. The association between obesity (BMI >/= 30 kg m2), dietary fat, other dietary patterns and other non-dietary factors were tested using multilinear regression analysis. The ratio of reported energy intake to energy requirement was used as an estimation of dietary underreporting.

RESULTS

The association between fatty acid fractions intake (saturated fatty acids (SFA) in women, and MUFA and polyunsaturated fatty acids (PUFA) in both sexes) and BMI was very weak, accounting for less than 1% of variance. All dietary and non-dietary variables accounted for 21% of variance in the measurement of BMI in women and only 6.7% of variance in men. Estimated underreporting of energy intake was 17.5% in obese women and 5.5% in obese men.

CONCLUSIONS

The association between consumption of specific types of dietary fat, olive oil and obesity in Spain is not very important. However, because of the cross-sectional design and some level of underreporting of energy intake observed in overweight subjects and overreporting in underweight subjects, systematic bias cannot be completely discarded.

Critical evaluation of energy intake using the Goldberg cut-off for energy intake:basal metabolic rate. A practical guide to its calculation, use and limitations

OBJECTIVES

To re-state the principles underlying the Goldberg cut-off for identifying under-reporters of energy intake, re-examine the physiological principles and update the values to be substituted into the equation for calculating the cut-off, and to examine its use and limitations.

RESULTS

New values are suggested for each element of the Goldberg equation. The physical activity level (PAL) for comparison with energy intake:basal metabolic rate (EI:BMR) should be selected to reflect the population under study; the PAL value of 1.55 x BMR is not necessarily the value of choice. The suggested value for average within-subject variation in energy intake is 23% (unchanged), but other sources of variation are increased in the light of new data. For within-subject variation in measured and estimated BMR, 4% and 8.5% respectively are suggested (previously 2.5% and 8%), and for total between-subject variation in PAL, the suggested value is 15% (previously 12.5%). The effect of these changes is to widen the confidence limits and reduce the sensitivity of the cut-off.

CONCLUSIONS

The Goldberg cut-off can be used to evaluate the mean population bias in reported energy intake, but information on the activity or lifestyle of the population is needed to choose a suitable PAL energy requirement for comparison. Sensitivity for identifying under-reporters at the individual level is limited. In epidemiological studies information on home, leisure and occupational activity is essential in order to assign subjects to low, medium or high PAL levels before calculating the cut-offs. In small studies, it is desirable to measure energy expenditure, or to calculate individual energy requirements, and to compare energy intake directly with energy expenditure.

The problem of accuracy in dietary surveys. Analysis of the over 65 UK National Diet and Nutrition Survey

STUDY OBJECTIVE

To investigate the prevalence and nature of low energy reporting in a dietary survey of British adults over 65 years of age.

DESIGN

Randomly selected cross sectional sample of 2060 British adults over 65 years. Four day weighed food diaries and questionnaires on health, lifestyle and socioeconomic characteristics.

SETTING

Great Britain.

PARTICIPANTS

539 women and 558 men over 65 years who were free living and completed four day food diaries.

MAIN RESULTS

A high proportion of men and women were classified as low energy reporters (LERs). Reported consumption of full fat dairy products, sugar and sweet foods, and alcoholic drinks differed most between LERs and non-LERs. Among LERs, reported protein and starch intakes were higher, fat, sugar and alcohol intakes were lower. LERs of either sex were more likely to be obese, male LERs were also more likely to belong to the manual social classes.

CONCLUSIONS

The high level of low energy reporting probably resulted from a coalescence of factors such as the weighed diary methodology and a reluctance to report consumption of unhealthy foods. The use of validatory biomarkers such as doubly labelled water needs to be more widespread.

Underreporting of energy intake in four populations of African origin

OBJECTIVE

To investigate the frequency of dietary underreporting in four African populations in different geographic and cultural settings.

SUBJECTS

Seven-hundred and forty three men and women from rural Cameroon, 1042 men and women from urban Cameroon, 857 men and women from Jamaica and 243 male and female African Caribbeans from the UK. Subjects who reported dieting or weight control were excluded.

MEASUREMENTS

Habitual dietary intake was estimated with a quantitative food frequency questionnaire, developed specifically for each country. Underreporting was defined using three cut-off levels for energy intake/estimated basic metabolic rate (EI/BMRest), based on age, sex and weight, in each site.

RESULTS

The EI/BMRest was highest in rural Cameroonian men at 3.07 (95% confidence interval: 2.97, 3.17) and women at 2.84 (2.74, 2.94), intermediate in urban Cameroon and Jamaica and lowest in the UK men and women at 1.44 (1.26, 1.62) and 1.41 (1.21, 1.61). This trend existed even after adjustment for age, BMI and education (P for trend<0.0001). The trend in the frequency of underreporting using the lowest cut-off level for EI/BMRest of 1.15 was 6% and 6% in rural Cameroon for women and men, respectively, 4% and 5% in urban Cameroon, 24% and 19% in Jamaica and 28% and 39% in the UK. With higher cut off levels this trend was similar.

CONCLUSION

The results suggest that the frequency of dietary underreporting differs between societies and that Westernization may be one of the factors underlying this phenomenon.

In-person vs telephone-administered multiple-pass 24-hour recalls in women: validation with doubly labeled water

OBJECTIVE

To determine the accuracy of energy intakes estimated with the multiple-pass 24-hour recall method in women by conducting in-person and telephone interviews. Doubly labeled water measurements of total energy expenditure were used for validation.

SUBJECTS

Thirty-five weight-stable women (mean age = 30 years, range = 19 to 46 years) participated.

DESIGN

Total energy expenditure was measured over a 14-day period using the doubly labeled water method. During this time, 4 multiple-pass 24-hour recalls were obtained from the women (2 in-person, 2 by telephone) who were provided 2-dimensional food models to estimate portion sizes. The Food Intake Analysis System was used to analyze recall data.

STATISTICAL ANALYSES

Paired t tests were conducted to examine differences between energy intake estimated from the telephone and in-person interviews. Agreement between the energy intake estimates from the telephone recalls and the in-person recalls was assessed using the technique of Bland and Altman. Paired t tests were used to compare energy intake estimated from the telephone and in-person recalls to total energy expenditure.

RESULTS

No significant difference in mean daily energy intake was found between the telephone (2,253 +/- 688 kcal) and in-person (2,173 +/- 656 kcal) interviews (P = .36). However, the mean energy intake from each interview method was significantly lower than total energy expenditure (2,644 +/- 503 kcal) (P = .006 and .001, respectively).

APPLICATIONS/CONCLUSIONS

Underreporting of energy intake was widespread in the sample. Although the multiple-pass 24-hour recall method did not generate a group measure of energy intake that was accurate or unbiased, the telephone-administered multiple-pass 24-hour recall was just as effective in estimating energy intake as the recall administered in-person. Dietetics professionals should be aware of the pervasive and serious problem of under-reporting of self-reported food intakes.

Food patterns defined by cluster analysis and their utility as dietary exposure variables: a report from the Malmö Diet and Cancer Study

OBJECTIVE

To explore the utility of cluster analysis in defining complex dietary exposures, separately with two types of variables.

DESIGN

: A modified diet history method, combining a 7-day menu book and a 168-item questionnaire, assessed dietary habits. A standardized questionnaire collected information on sociodemographics, lifestyle and health history. Anthropometric information was obtained through direct measurements. The dietary information was collapsed into 43 generic food groups, and converted into variables indicating the per cent contribution of specific food groups to total energy intake. Food patterns were identified by the QUICK CLUSTER procedure in SPSS, in two separate analytical steps using unstandardized and standardized (Z-scores) clustering variables.

SETTING

: The Malmö Diet and Cancer (MDC) Study, a prospective study in the third largest city of Sweden, with baseline examinations from March 1991 to October 1996.

SUBJECTS

A random sample of 2206 men and 3151 women from the MDC cohort (n = 28 098).

RESULTS

Both variable types produced conceptually well separated clusters, confirmed with discriminant analysis. 'Healthy' and 'less healthy' food patterns were also identified with both types of variables. However, nutrient intake differences across clusters were greater, and the distribution of the number of individuals more even, with the unstandardized variables. Logistic regression indicated higher risks of past food habit change, underreporting of energy and higher body mass index (BMI) for individuals falling into 'healthy' food pattern clusters.

CONCLUSIONS

The utility in discriminating dietary exposures appears greater for unstandardized food group variables. Future studies on diet and cancer need to recognize the confounding factors associated with 'healthy' food patterns.