Food photography II: use of food photographs for estimating portion size and the nutrient content of meals

Effects of a Web-based food portion training program on food portion estimation

OBJECTIVE

Assess the effects of a prototype computerized food portion tutorial (CFPT).

DESIGN

Participants were randomly assigned to estimate portion sizes for selected food items either prior to or following CFPT training (between groups), and those estimating before CFPT training re-estimated portions after training (within groups).

SETTING

Research offices.

PARTICIPANTS

Seventy-six adult participants without dietary restrictions.

INTERVENTION

The CFPT is a Web-based food portion training program that displays varied portions of 23 food items with user-controllable reference objects and viewing angles.

MAIN OUTCOME MEASURES

Estimated vs. weighed portions of food items selected for a meal.

ANALYSIS

Nonparametric tests were performed on estimated vs. weighed portion differences and on accuracy ratios between and within groups.

RESULTS

A significant difference was found between conditions, both within and between groups, on the discrepancy between estimated and weighed portions for a number of the food items. Training exposure, however, resulted primarily in a shift from underestimation to overestimation, not more accurate estimation.

IMPLICATIONS FOR RESEARCH AND PRACTICE

The CFPT produced a significant impact on food portion estimation but appeared to sensitize participants to underestimation errors, leading to overestimation errors. Computerization of food portion training programs holds promise for providing cost-efficient portion estimation training but requires further development and evaluation before being considered for clinical use.

Dietary intake measurements

Objective

To provide a concise summary of field and laboratory methods for the measurement of dietary intake with particular reference to the assessment of energy and protein intake and to the pitfalls and difficulties that may be encountered in practice when implementing the methods both in the field and under laboratory conditions.

Accuracy of estimates of food portion size using food photographs – the importance of using age-appropriate tools

Background

In order to obtain a measure of nutrient intake, a measure or estimate of the amount of food consumed is required. Weighing foods imposes a large burden on subjects, often resulting in underreporting. Tools are available to assist subjects in providing an estimate of portion size and these include food photographs. The application of these tools in improving portion size estimation by children has not been investigated systematically.

Objectives

To assess the accuracy with which children are able to estimate food portion sizes using food photographs designed for use with adults, and to determine whether the accuracy of estimates is improved when age-appropriate portion size photographs are provided.

Design

Original data from three separate studies, on the accuracy of portion size estimates by adults using food photographs, by children using adult photographs and by children using age-appropriate photographs, are analysed and compared.

Subjects

One hundred and thirty-five adults aged 18 to 90 years and 210 children aged 4 to 11 years.

Results

Children's estimates of portion sizes using age-appropriate food photographs were significantly more accurate (an underestimate of 1% on average) than estimates using photographs designed for use with adults (an overestimate of 45% on average). Accuracy of children's estimates of portion size using age-appropriate photographs was not significantly different from that of adults. Children overestimated a food's weight by 18% on average and adults underestimated by 5%.

Conclusions

Providing children with food photographs depicting age-appropriate portion sizes greatly increases the accuracy of portion size estimates compared with estimates using photographs designed for use with adults.

Desenvolvimento de um inquérito para avaliação da ingestão alimentar de grupos populacionais

OBJETIVOS: Este trabalho procurou desenvolver um instrumento para obtenção de dados relativos ao consumo alimentar, de caráter qualitativo e quantitativo, para avaliar a ingestão dietética em estudos populacionais. MÉTODOS: Inicialmente foram coletados dados sobre a ingestão alimentar de uma amostra representativa de moradores da cidade de Viçosa (n=119). Para conhecer os alimentos mais consumidos e seus porcionamentos, foram utilizados os métodos recordatório de 24h e pesagem direta. A entrevista ocorreu no horário do almoço ou jantar, com pesagem de todos os alimentos constantes na refeição e de porções referidas como consumidas nas últimas 24h, usou-se também álbum fotográfico como auxiliar na estimativa do peso da porção. RESULTADOS: A partir dos 60 alimentos mais consumidos e dos porcionamentos identificados, foi desenvolvido um inquérito baseado no método Freqüência de Consumo Alimentar semi-quantitativo, com 65 itens e um álbum fotográfico de alimentos. Realizou-se um estudo piloto para avaliação desta metodologia em uma sub-amostra (n=34). Para comparação entre os dois métodos, avaliaram-se o valor energético e os macronutrientes, utilizando o coeficiente de Pearson e o teste "t" de Student, tendo-se obtido: r=0,53 para energia, r=0,43 para proteína, r=0,58 para lipídeos e r=0,21 para carboidratos. Não foi detectada diferença significante entre os dois métodos para proteína e lipídeos, pelo teste "t" (alfa=0,05). CONCLUSÃO: O inquérito desenvolvido mostrou-se um instrumento promissor para inquéritos populacionais, no entanto, são necessários maiores estudos para averiguar as limitações e os possíveis desdobramentos do inquérito para atingir toda a população.

An evaluation of a colour food photography atlas as a tool for quantifying food portion size in epidemiological dietary surveys

OBJECTIVE

To test the validity of a colour food photography atlas for quantifying portion size eaten compared with weighed foods.

DESIGN

The colour food photography atlas was prepared by cooking, weighing and taking digital photographs of three portion sizes of 434 foods and beverages typical of the Italian diet.

SUBJECTS AND INTERVENTIONS

In all, 448 male and female volunteers aged 6-60 y from a wide variety of social backgrounds completed 9075 assessments of food portions eaten at lunch and dinner in relation to a set of colour food photographs during 8 weeks of investigation. The amounts of foods eaten by individuals in five different cafeterias in Pavia, Northern Italy, were weighed by trained investigators at the time of serving and, within 5-10 min of the end of the meal, each subject was asked to quantify all foods consumed with reference to one of the three food photographs or in terms of virtual portions among those shown in the photographs.

RESULTS

Multiple regression analysis shows that weights of portion sizes chosen from the set of photographs are significantly associated (P<0.05) to weights of eaten portions (beta=0.81; R(2)=0.70) and are independent of age, gender and BMI. The differences between mean weights of the portions chosen by individuals from photographs and mean weights of eaten foods are significant for all food categories (P<0.05), except for bread. However, because of the very large number of observations, the mean differences are very small (range: from +23.2 g (+11.2%) for first courses to -1.3 g (-2.7%) for bread). Bland-Altman plots show that first courses limits of agreement are wide because the dispersion is increasing while weights are rising.

CONCLUSIONS

The use of a series of three photographs and virtual portion sizes being associated with relatively small errors, our findings support the validity of using this colour food photography atlas as a tool for quantifying food portion size in epidemiological dietary surveys on different age groups of Italian subjects.

Can children and adolescents use photographs of food to estimate portion sizes?

OBJECTIVE

The goals of this study were to investigate whether children and adolescents can accurately estimate portion sizes of preweighed food by viewing photographs of food, and whether age influences the ability to estimate food portion sizes.

SUBJECTS

A total of 63 male and female volunteers aged 9-19 y participated in the study.

DESIGN

Each participant received a photographic booklet with photograph series of 13 food items. Participants over 10 y of age were asked to estimate portion sizes of food on 34 plates placed in front of them by comparing the different portions to corresponding photographs of food. Younger participants were asked to estimate portion sizes of food on 17 plates by comparing the portions to photographs.

RESULTS

Participants made 2019 comparisons between actual food portion sizes and photographs of food portion sizes. On average, 60% of the comparisons were made correctly. A photograph directly adjacent to the photograph depicting the correct portion size was chosen in 35% of the comparisons and 5% of the comparisons were made incorrectly. Portion sizes were estimated more accurately when the actual served portions of food had exactly the same appearance as the foods portrayed in the photographic booklet. No differences existed between children's and adolescents' abilities to estimate portion sizes using photographs.

CONCLUSIONS

Large variability may exist in an individual's capability of choosing a photograph that correctly depicts food portion sizes, but the error at the group level is quite small. These data indicate that a photographic booklet of foods can be a useful tool for portion size estimates in these age groups.

SPONSORSHIP

The Norwegian Foundation for Health and Rehabilitation through Norwegian Health Association.

A semiquantitative food frequency questionnaire is a valid indicator of the usual intake of phytoestrogens by south Asian women in the UK relative to multiple 24-h dietary recalls and multiple plasma samples

We investigated the relative validity of an interview-administered FFQ to estimate phytoestrogen intake among South Asian women in the UK. A population-based sample of 108 healthy South Asian women completed random repeated monthly 24-h recalls [with a subsample (n = 58) also providing multiple plasma samples] over a period of 1 y followed by administration of the FFQ. The FFQ produced slightly higher estimates of phytoestrogen intake than the 24-h recalls, but the percentage of women classified into the same +/- 1 quartile by the 2 methods was high for all phytoestrogens (from 81 to 94%) with only a small percentage (<5%) being misclassified into extreme opposite quartiles. Energy-adjusted Spearman correlations coefficients between the estimates obtained by the FFQ and the 24-h recalls were 0.55 for genistein, 0.60 for daidzein, 0.70 for secoisolariciresinol, and 0.63 for matairesinol (all P < 0.001). Spearman correlation coefficients between the FFQ estimates and plasma levels were 0.21 (P = 0.12) for genistein, 0.32 (P = 0.02) for daidzein and 0.10 (P = 0.43) for enterolactone; the corresponding values for the 24-h recalls compared with plasma levels were 0.43 (P < 0.001), 0.40 (P = 0.002), and 0.08 (P = 0.50), respectively. The method of triads was used to estimate the validity coefficients (VCs) between the estimates provided by each assessment method and "true intake." The FFQ had the highest VC for lignans (0.91 vs. 0.73 for 24-h recalls and 0.11 for plasma samples) and satisfactory VCs for both genistein (0.46 vs. 0.95 and 0.45, respectively) and daidzein (0.67 vs. 0.83 and 0.45, respectively). This FFQ is thus a relatively valid tool with which to estimate phytoestrogen intake among South Asian women in the UK.

Influence of individually estimated portion size on the assessment of nutritional risk in colorectal cancer in Portugal

We evaluated the influence of individually estimated portion sizes on the estimate of nutrient related risk of colorectal cancer, using data from a Portuguese hospital based case-control study on diet and colorectal cancer. A total of 100 patients with colorectal adenocarcinoma (aged 15-92 years) and 211 controls (aged 36-89 years) were included. Two data sets were created for nutrient analysis, the first one allowed estimates of food intake using data on portion size as collected with visual aids during the interview. The second estimate substituted respondents' estimate with a standard portion size, as used in the semi-quantitative (SQ) food frequency approach. The two analytic approaches yielded similar energy and nutrient intakes in cases and controls. The percent range of concordance is acceptable, in the same quartile varying from 44 to 82% (mean: 56%) and very good in the same or adjacent (+/-1) quartile (mean: 91%, range: 85-97%). The two estimates lead to a similar pattern of multivariate odd's ratio, however the SQ estimates resulted in more significant findings. We conclude that little extra information is gained by including individual portion size information when assessing diet-related risk of colorectal cancer.

Assessment of fecal output in patients receiving enteral tube feeding: validation of a novel chart

OBJECTIVE

To develop a practical, valid and reliable chart to assist in the accurate visual characterization of fecal output in patients receiving enteral tube feeding (ETF).

DESIGN

A chart incorporating verbal and pictorial descriptors of fecal output was developed. Validity and reliability were assessed by a questionnaire survey of health professionals and a clinical study of patients commencing ETF. Content validity was assessed from the results of the questionnaire, construct validity by contrasting groups analysis, concurrent validity by comparison of the chart with actual fecal weight and inter-rater reliability by independent characterization of the same fecal sample by two nurses.

SETTING

St George's Hospital, London, UK.

SUBJECTS

In all, 35 health professionals completed a questionnaire with respect to the chart. The chart was then used to monitor fecal output in 36 patients commencing ETF for a total of 171 patient-days, during which time nurses used the chart to characterize 269 fecal samples, of which 59 were subsequently weighed.

RESULTS

The results of the questionnaire suggested good content validity. The chart demonstrated statistically significant differences in fecal frequency, fecal consistency, fecal score and incidence of diarrhea for contrasting patient groups expected to have different fecal output (P < 0.05). The inter-rater reliability was almost perfect for fecal consistency (95% agreement, kappa = 0.91) and substantial for fecal weight (83%, kappa = 0.75). In all, 83% of fecal samples were assigned to the correct weight category (kappa = 0.75).

CONCLUSION

The chart has good content, construct and concurrent validity and inter-rater reliability, and is suitable for both research and clinical use.

SPONSORSHIP

This research was jointly supported by King's College London and Nestlé, UK.

The effect of a dietary preload on estimation of usual food portion size by photograph in female volunteers

BACKGROUND

The aim of this study was to investigate whether a subject's level of satiety influences perception of their usual portion size.

METHODS

A total of 62 school children were recruited for the pilot study. Half of the group assessed food photographs for their usual portion size before lunch, and half after lunch. For the main study, 55 female students were recruited to test within-subject variation in perception of usual portion size before and after consuming a preload.

RESULTS

Significant differences in perception of portion size were found for four of the six foods used.

CONCLUSION

Some subjects' perception of their usual portion size was influenced by their level of satiety. Further study is needed to investigate this using a wider variety of food photographs and an alternative preload.

Dietary beliefs of people with ulcerative colitis and their effect on relapse and nutrient intake

BACKGROUND & AIMS

Ulcerative colitis usually follows a relapsing and remitting course. Patients believe that dietary factors are important. We wished to determine the nature of and reasons for patients' dietary beliefs and their effect on relapse and nutrient intake.

METHODS

In a 1-year prospective cohort study, patients' nutrient intake and disease activity were measured with a validated food frequency questionnaire and disease activity index. Food beliefs, demographics and disease characteristics were recorded. The influence of beliefs on the risk of relapse and nutrient intake were examined using chi-squared and Mann-Whitney U-tests.

RESULTS

One hundred and eighty-three patients were studied and 52% relapsed. Sixty-eight per cent held dietary beliefs and reported modifying their intake accordingly. The most common reported behaviour was the avoidance of milk and dairy products. Food beliefs were more common amongst those who had received dietary advice. No reported behaviour reduced the risk of relapse, but patients who avoided dairy products had a significantly lower intake of calcium. Folate intake was below UK recommended levels in 13% of patients.

CONCLUSIONS

Patients with ulcerative colitis believe that many foods are harmful or helpful to their disease activity. Commonly held beliefs do not modify the risk of relapse, but do adversely affect nutrient intake.

Validity and reproducibility of a computerised tool for assessing the iron, calcium and vitamin C intake of Belgian women

OBJECTIVE

To determine the relative validity of a newly developed iron intake assessment tool, designed specifically to assess iron, calcium and vitamin C intake.

DESIGN

Estimates of iron, calcium and vitamin C intake from a computerised iron intake assessment tool compared with those from 11-day estimated dietary records.

SETTING

Region of Ghent (N= +/- 225,000), a city in Flanders, the Dutch-speaking part of Belgium.

SUBJECTS

In all, 50 women aged 18-39 y, participating in a large-scale epidemiological study on iron intake and iron status.

MAIN RESULTS

Mean dietary iron intake from the 11-day food record, the unadjusted dietary iron intake assessment tool and the adjusted tool was, respectively, 10.5 +/- 2.7, 10.4 +/- 4.3 and 9.6 +/- 2.9 mg. For the different nutrients, the correlation coefficients vary from 0.45 to 0.60 for adjusted intake. The mean difference of iron intake by the two methods (0.8 +/- 2.9 mg) did not differ significantly from zero. The new method correctly classified 38% (iron), 38% (calcium) and 58% (vitamin C) of the subjects to the correct tertile. The correlation coefficients ranged from 0.48 for adjusted vitamin C intake to 0.73 for adjusted calcium intake between two administrations.

CONCLUSION

The newly developed instrument can be used to assess mean group intakes of iron, calcium and vitamin C in women consuming a Western diet. However, since the ranking capability of the new tool is rather weak, further refinement of the tool is required to produce a robust method for assessing iron, calcium and vitamin C intakes of individuals.

SPONSORSHIP

This research was supported by the Belgian National Fund for Scientific Research/Flemish Division (Fund No G.0152.01).

Intake of dietary iron is low in patients with Crohn's disease: a case-control study

Patients with Crohn's disease (CD) often experience Fe deficiency (ID) and frequently alter their diet to relieve abdominal symptoms. The present study set out to assess whether patients with CD have dietary habits that lead to low Fe intakes and/or reduced bioavailable Fe compared with control subjects. Patients with asymptomatic CD were matched to controls (n 91/group). Dietary intakes of Fe and contributions from different food groups were compared using a 7 d food diary. Promoters and inhibitors of non-haem Fe absorption were investigated and a recently published algorithm was applied to assess bioavailable Fe. Fewer patients than controls met the reference nutrient intake for Fe (32% CD patients v. 42% controls). Overall, patients had significantly lower mean Fe intakes (by 2.3 mg/d) and Fe density (by 0.26 mg/MJ (1.1 mg/1000 kcal)) compared with controls (both P<0.001). Differences were mainly due to a preference among CD patients for low-fibre non-Fe fortified cereals, particularly breakfast cereals. In particular, control subjects had higher Fe intakes than matched CD subjects for men (P<0.001) and women less than 50 years (P=0.03). Intakes of both ascorbic acid (P<0.001) and phytic acid (P<0.01), but not animal tissue (P=1.0), were lower in patients with CD, but these had no overall effect on the predicted percentage of bioavailable Fe. Thus total bioavailable Fe was reduced in patients with CD due to lower intakes (P<0.01). Dietary Fe intakes are low in CD patients, which may contribute to an increased risk of ID and anaemia. Changing dietary advice may compromise perceived symptoms of the disease so the need for Fe supplementation should be carefully considered.

The estimation of food portion sizes: a comparison between using descriptions of portion sizes and a photographic food atlas by children and adults

BACKGROUND

Food Photographs and standard portion sizes have been used with adults to assess portion size when recording dietary intake. The effectiveness of these methods may be reduced when memory/recall is required and children may have problems using these techniques.

METHODS

Adults (47) and children (37) were recruited from amongst university personnel, their children and children's friends to assess portion sizes of nine self-served amounts of selected food items using food photographs and standard descriptions of portion sizes. Portion sizes were estimated directly after self-serving and three - 4 days later.

RESULTS

Substantial differences in the estimate of portion sizes were observed for most foods regardless of the method used or the age of the subjects, median difference range: -52-100%. For children there were greater errors using both methods than for adults. Significant differences were found between the two methods of estimating weight. The food atlas provided higher median estimated weights for the majority of the food items. There were very few differences in the estimation of portion sizes between the two testing periods.

CONCLUSION

The findings would suggest that either an alternative method or a modification of the methods used here for estimating portion sizes in young subjects, for example standard food portion sizes for children of different ages such as those that are being developed by the Food Standards Agency, would be more appropriate.

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.

Lifelong vegetarianism and risk of breast cancer: a population-based case-control study among South Asian migrant women living in England

To investigate the role of lifelong vegetarianism on the aetiology of female breast cancer, we conducted a population-based case-control study among South Asian migrant women from the Indian subcontinent resident in England. A total of 240 South Asian breast cancer cases were identified from 2 cancer registries during 1995-1999. For each case, 2 age-matched South Asian controls were randomly selected from the age-sex register of the case practice. Lifelong vegetarians had a slight reduction, although not statistically significant, in the odds of breast cancer relative to lifelong meat-eaters, which persisted after adjustment for socio-demographic and reproductive variables [odds ratio (OR)=0.77; 95% confidence interval (CI)=0.50-1.18]. Analysis by food group revealed no linear trend in the odds of breast cancer with increasing consumption of meat (p=0.10) but the odds were higher for women in the top 75%. In contrast, there were strong inverse trends in the odds of breast cancer with increasing intake of vegetables (p=0.005), pulses (p=0.007) and fibre [non-starch polysaccharides, NSP (p=0.02)], with women in the highest 25% of intake of these foods having about 50% of the odds of those in the lowest ones. Adjustment for intake of vegetables and pulses reverted the odds of breast cancer in lifelong vegetarians relative to lifelong meat-eaters (OR=1.04; 95% CI=0.65-1.68) and attenuated the quartile-specific estimates for meat intake, whereas the inverse trends in the odds of breast cancer with intake of vegetables and pulses remained after adjustment for type of diet or meat intake. These findings suggest that lifelong vegetarianism may be associated with a reduction in the risk of breast cancer through its association with a higher intake of vegetables and pulses. Although it is not possible to exclude the possibility that lifelong meat abstention may also play a role, the findings provide evidence that a diet rich in vegetables and pulses, such as those typically found in South Asian diets, may be protective against this cancer.

Energy intake by multiple pass 24 h recall and total energy expenditure: a comparison in a representative sample of 3-4-year-olds

The accuracy of the multiple pass 24 h recall for assessment of habitual energy intake in pre-school children is unclear. The primary aim of this study was to assess its accuracy by comparison with measurement of total energy expenditure by doubly-labelled water in a representative sample of forty-one 3-4-year-olds. The recall method was well tolerated by subjects and was administered quickly and easily. However, it produced estimates of energy intake which significantly exceeded measures of total energy expenditure from doubly-labelled water, mean paired difference 660 kJ/d (P<0.01). Agreement between the two methods was poor at the individual level: limits of agreement 660+/-3018 kJ/d. Error and imprecision in both methods contribute to individual differences, but the present study suggests that the multiple pass 24 h recall does not provide accurate estimates of dietary energy intake in individual children.

Effect of glucocorticoid therapy on energy intake in children treated for acute lymphoblastic leukemia

Despite a widespread belief that glucocorticoid therapy is associated with positive energy balance and excess weight gain there is a dearth of quantitative evidence about its effects and the underlying mechanisms of any effects. The primary aim of the present study was to quantify the effect of dexamethasone and prednisone treatment on energy intake in children treated for childhood acute lymphoblastic leukemia. A secondary aim was to test for differences in excess weight gain between patients treated using the 2 glucocorticoids. We measured energy intake in 26 patients (mean +/- SD age, 6.3 +/- 2.3 yr) during a 5-d period "on" steroids and again in the week before steroid treatment. Changes in body mass index from diagnosis to 1 and 2 yr postdiagnosis were expressed as SD scores. Steroid treatment was associated with a significant increase in energy intake of approximately 20% (mean paired difference, 1.7 MJ/d; SD, 2.8; 95% confidence interval, 0.7-2.8 MJ/d), with no significant difference between the 2 steroids. The mean change in body mass index SD score was +0.38 (SD, 1.10; P < 0.05) to 1 yr and +0.68 (SD, 1.38; P < 0.05) to 2 yr, with no significant difference between the 2 groups of patients. Glucocorticoid treatment in childhood acute lymphoblastic leukemia increases energy intake markedly, and this effect contributes to the excess weight gain and obesity characteristic of patients being treated for acute lymphoblastic leukemia.

Comparison of a dietary record using reported portion size versus standard portion size for assessing nutrient intake

OBJECTIVE

Because the percentage of missing portion sizes was large in the Aerobics Center Longitudinal Study (ACLS), careful consideration of the accuracy of standard portion sizes was necessary. The purpose of the present study was to investigate the consequences of using standard portion sizes instead of reported portion sizes on subjects' nutrient intake.

METHODS

In 2307 men and 411 women, nutrient intake calculated from a 3-day dietary record using reported portion sizes was compared with nutrient intake calculated from the same record in which standard portion sizes were substituted for reported portion sizes.

RESULTS

The standard portion sizes provided significantly lower estimates (>/= 20%) of energy and nutrient intakes than the reported portion sizes. Spearman correlation coefficients obtained by the two methods were high, ranging from 0.67 to 0.93. Furthermore, the agreement between both methods was fairly good. Thus, in the ACLS the use of standard portion sizes rather than reported portion sizes did not appear to be suitable to assess the absolute intake at the group level, but appeared to lead to a good ranking of individuals according to nutrient intake. These results were confirmed by the Continuing Survey of Food Intake by Individuals (CSFII), in which the assessment of the portion size was optimal. When the standard portion sizes were adjusted using the correction factor, the ability of the standard portion sizes to assess the absolute nutrient intake at the group level was considerably improved.

CONCLUSIONS

This study suggests that the adjusted standard portion sizes may be able to replace missing portion sizes in the ACLS database.

The development and testing of a food portion photograph book for use in an African population

OBJECTIVE: To develop and test a book of photographs of commonly eaten foods to be used as a visual aid in the description of portion sizes in a large cross-sectional study on the health profile of Africans in transition (THUSA - Transition, Health and Urbanization in South Africa). SETTING: Clinics in the North West Province of South Africa. PARTICIPANTS: One hundred and sixty-nine adult African volunteers DESIGN: Data on commonly eaten foods, preparation methods, recipes and portion sizes were collected in a pilot study. Colour photographs, taken of foods prepared by the researchers and measured into three or four portion sizes, were enlarged and put together in a book. The food portion photograph book (FPPB) was tested by presenting subjects with a portion of real food and asking them to estimate the portion size by matching it with one of the portion photographs. MAIN RESULTS: Of 2959 portions tested, 68% were accurately estimated (estimated weight within 10% of actual weight). Clearly defined solid foods were better estimated than foods that had an amorphous appearance. Accuracy of estimation was not affected by gender, age or education. CONCLUSION: The FPPB was accepted as a useful and convenient visual aid to estimate portion sizes in the cross-sectional dietary intake study.

An evaluation of food photographs as a tool for quantifying food and nutrient intakes

OBJECTIVE

To evaluate the errors incurred by young adults using single portion size colour food photographs to quantify foods and nutrients consumed at six meals on two non-consecutive days.

DESIGN

Breakfast menus remained the same for the 2 days; but lunch and dinner menus varied. The amounts of food eaten by individuals were determined by weighing individual serving dishes pre- and post-consumption. The day after eating, all foods consumed were quantified in terms of fractions or multiples of the amounts shown in the food photographs.

SUBJECTS

Thirty adult volunteers (15 male, 15 female), aged 18-36 years, completed the protocol for day one; 27 (90%) completed day two.

RESULTS

Some foods were more difficult to quantify accurately than others. The largest error range was -38. 9% to +284.6% (cheese), whereas the smallest errors were incurred for juice (-21.5% to +34.6%, day one). All subjects who consumed muesli (day one) overestimated (+3.7% to +113.7%). No other foods were consistently over- or underestimated. For foods consumed at breakfast by the same subjects on both days, individual estimation errors were inconsistent in magnitude and/or direction. At the group level, most nutrients were estimated to within +/-10% of intake; exceptions were thiamin (+10.5%, day one) and vitamin E (-10.1%, day one; -15.3%, day two). Between 63% and 80% of subjects were correctly classified into tertiles on the basis of estimated intakes.

CONCLUSIONS

Despite some large food quantification errors, single portion size food photographs were effective when used to estimate nutrient intakes at the group level. It remains to be established whether, under the conditions used in this study, more photographs per food would improve estimates of nutrient intake at the individual level.

Nutritional intake monitoring for nursing home residents: a comparison of staff documentation, direct observation, and photography methods

BACKGROUND

The current approach to assessing nutritional intake requires nursing home (NH) staff to document total percentage of food and fluid consumed at each meal. Because NH staff tend to significantly overestimate total food intake, methods need to be developed to improve the accuracy of food intake measurement.

OBJECTIVE

To compare three methods of assessing the nutritional intake of NH residents.

RESEARCH DESIGN

Validation Study.

SUBJECTS

Fifty-six NH residents in one facility.

MEASURES

Total percentage of food and fluid intake of each resident for each of nine meals, or all three meals for 3 consecutive days, was assessed by: (1) Nursing home staff chart documentation, (2) Research staff documentation according to direct observations, and (3) Research staff documentation according to photographs of residents' trays before and after each meal.

RESULTS

Research staff documentation of total intake and intake of all individual food and fluid items was similar for the direct observation and photography methods. In comparison with these two methods, NH staff documentation reflected a significant overestimate (22%) of residents' total intake levels. In addition, NH staff failed to identify the more than half (53%) of those residents whose intake levels were equal to or below 75% for most meals.

CONCLUSIONS

The photography method of nutritional assessment yielded the same information as direct observations by research staff, and both of these methods showed the intake levels of NH residents to be significantly lower than the intake levels documented by NH staff. The photography method also has several advantages over a documentation system that relies on an observer to be present to record food and fluid intake levels.

Food consumption patterns in the adult population of the Basque Country (EINUT-I)

OBJECTIVE

Dietary surveys are a valuable tool in nutrition surveillance programmes to monitor the nutritional status of a group or population of a country. The objective of this study was to assess the food consumption pattern in the adult population of the Basque Country (Spain).

DESIGN

A cross-sectional nutritional survey was carried out in 1990. Dietary habits were assessed by means of '24-h recall' during 3 non-consecutive days and a food frequency questionnaire.

SETTING

Population survey in the Basque Country (Spain).

SUBJECTS

Random sample of the adult population (25-60 years) in the Basque Country (n = 2348).

RESULTS

Results draw a food pattern characterized by a high consumption of meat, 163+/-3.04 g day(-1) (mean +/- SEM), supplied mainly by poultry, butchery products, veal and fish (88+/-2.68 g day(-1)). The average consumption of milk and dairy products was 359+/-5.19 g day(-1), although 39% of the sample did consume less than 2 portions from this group of foods daily. Olive oil was the most widely used fat for cooking (45%), followed by sunflower seed oil (30%). Cereals supplied 21.5% of the average energy intake and the consumption of vegetables and garden products was 159+/-3.13 g day(-1). Only 29% of the group usually had 2 or more portions of vegetables per day. Women consumed higher amounts of chocolate, cookies, sweets and coffee (P < 0.01) than men. Younger adults consumed more meat (P < 0.01), while the older community consumed more fish, vegetables and fruit (P < 0.01). More highly educated people consumed more dairy products, vegetables and butter (P < 0.01). Conversely, less educated people consumed higher amounts of olive oil, pulses and bread (P < 0.01).

CONCLUSIONS

The dietary pattern observed in the Basque Country, although in keeping with its traditions, is in harmony with the actual dietary trends in Mediterranean countries. In order to satisfy the dietary guidelines suggested by the Spanish Society of Community Nutrition, it would be desirable to gradually increase the consumption of vegetables, fresh garden produce, fruit and cereals. At the same time, it would be advisable to decrease the consumption of animal products (whole fat dairy products, meat, added fats) so the proportion of energy intake from fat can be reduced by 5% (3% from saturated fatty acids).