Modeling Data with Excess Zeros and Measurement Error: Application to Evaluating Relationships between Episodically Consumed Foods and Health Outcomes

Summary Dietary assessment of episodically consumed foods gives rise to nonnegative data that have excess zeros and measurement error. Tooze et al. (2006, Journal of the American Dietetic Association 106 , 1575–1587) describe a general statistical approach (National Cancer Institute method) for modeling such food intakes reported on two or more 24‐hour recalls (24HRs) and demonstrate its use to estimate the distribution of the food's usual intake in the general population. In this article, we propose an extension of this method to predict individual usual intake of such foods and to evaluate the relationships of usual intakes with health outcomes. Following the regression calibration approach for measurement error correction, individual usual intake is generally predicted as the conditional mean intake given 24HR‐reported intake and other covariates in the health model. One feature of the proposed method is that additional covariates potentially related to usual intake may be used to increase the precision of estimates of usual intake and of diet‐health outcome associations. Applying the method to data from the Eating at America's Table Study, we quantify the increased precision obtained from including reported frequency of intake on a food frequency questionnaire (FFQ) as a covariate in the calibration model. We then demonstrate the method in evaluating the linear relationship between log blood mercury levels and fish intake in women by using data from the National Health and Nutrition Examination Survey, and show increased precision when including the FFQ information. Finally, we present simulation results evaluating the performance of the proposed method in this context.     

Factors Influencing the Nutritional Health and Food Choices of African American HIV-Positive Marginally Housed and Homeless Female Substance Abusers

The toll of HIV/AIDS and drug abuse on economically disadvantaged women of color in the United States is a public health problem of epidemic proportions. Malnutrition, believed to be pervasive in this population, exacerbates the devastating health effects of addiction and HIV. This study documented dietary deficiencies in this population and examined factors influencing the food choices and eating patterns of marginally housed and homeless African American HIV-positive substance abusing women. Data were collected from 28 women ages 19–55 using two 24-hour dietary recalls and a semi-structured interview guide. Data revealed multiple nutritional intake hazards including skipped meals, substitution of carbohydrate-laden foods for dairy foods rich in animal fat and proteins, and an absence of raw fruits and vegetables indicative of deficiencies in key macro- and micronutrients. Food risks were increased for homeless women who were more likely to lack public assistance, have difficulty accessing free food service, and frequently eating food from dumpsters. Qualitative data analysis of interviews generated three major themes describing the context in which nutritional deficiencies emerged: (1) diet-disease and food-safety misconceptions; (2) socio-cultural and lifestyle barriers; and (3) lack of personal resources and neighborhood food availability and affordability. The relevance of these findings to nutrition intervention programs for this population is discussed.     

Estimating energy intake of urban women in Colombia: Comparison of diet records and recalls

As part of a larger study of energy-nutrition, we compared the performance of 24 h diet recalls with estimated diet records kept by trained observers. The subjects were economically disadvantaged women (n = 85) in the city of Cali, Colombia. A 24 h recall and an estimated diet record were collected for each woman at 0 and approximately 3 and 6 months. Energy intake obtained from the estimated dietary records was validated against energy expenditure and used as the reference method. Energy and macronutrient intake were calculated from published food composition tables and proximate analyses of common foods. The number of food items consumed per woman per day, total and in each of 16 food groups, was tabulated. Energy and macronutrient intakes were 11–13% lower in the 24 h recalls. The discrepancy energy could be largely accounted for by the lower number of food items in the recalls. The number of food items in eight of 16 food groups was significantly lower in the recalls compared to the records. Underreporting on the recalls was a general tendency in these subjects and not clearly related to average energy intake. We conclude that 24 h diet recalls underestimate energy and nutrient intake in this population and are not suitable for studies of human energetics. Am J Phys Anthropol 108:53–63, 1999. © 1999 Wiley-Liss, Inc.     

Do Children Eat What They Say? Validity of Intended Food Choices Among Native American School Children

Objective. To examine the agreement between school children's intended food choices and observed food choices. Design. Native American students in the second through fifth grade completed a questionnaire that asked them to select from 10 paired food choices for a given meal or snack. Three weeks later students chose among foods identical to those on the questionnaire as part of their usual school lunch or breakfast over three consecutive days; afternoon snacks were also offered. Results. Agreement between students' intended food choices and observed food choices was examined across 10 food pairs. The composite K coefficient between intended and observed food choices was 0.09 (95% confidence interval 0.06, 0.12), indicating virtually no agreement above that expected by chance. There were no differences in agreement by sex or grade. Conclusions. Intended food choices were not significantly associated with observed food choices. It is unclear whether intended food choices reflect nutrition knowledge, socially desirable responses, food preferences, or some other dimension of eating behavior. Although responsive to school-based nutrition interventions, the interpretation of changes in intended food choices must be clarified in future research.     

Diet of wild boar Sus scrofa in Western Europe, with particular reference to consumption of agricultural crops

1. The diet of wild boar Sus scrofa in Western Europe is reviewed, paying particular attention to the consumption of agricultural crops and the implications of this from the point of view of crop damage. Data were taken mainly from 11 studies that provide quantitative information about the consumption of different food types, but we also list all the foods reported as being eaten by wild boar in a total of 21 studies. 2. Vegetable foods occurred more frequently in the diet than animal foods, and also constituted the bulk of the food ingested. Overall, there were four major vegetable food categories: mast, roots, green plant matter and agricultural crops. Depending on the study area, wild boar always consumed at least one energy‐rich plant food such as acorns, beechnuts, chestnuts, pine seeds, olives, cereal grains or other crops. The number and types of agricultural crops consumed varied between study areas but crops represent an important component of wild boar diet throughout its Western European range. Among animal foods, insects, earthworms, birds and mammals were eaten most consistently but the diet also included amphibians, reptiles, gastropods and myriapods. 3. Seasonal, interannual and regional differences in the diet, together with its striking overall breadth, indicate that wild boar are opportunistic omnivores whose diet, in any particular instance, is largely determined by the relative availability of different food types. Dependence on energy‐rich plant material as a major component of the diet, coupled with large body size and a propensity to trample crops as well as consume them, means that wild boar cause significant agricultural damage.     

Energy Intake and Physical Activity in Pima Indians: Comparison with Energy Expenditure Measured by Doubly-Labeled Water

To test the validity of survey techniques for measuring diet and activity patterns of Pima Indians, sequential 24-hour recalls, a food frequency ques tionnaire (FFQ), and an activity questionnaire were compared to free-living energy expenditure. Total energy expenditure (TEE) measured by doubly labeled water was 13.27 ± 2.95 MJ/d for the 12 males (mean±SD: 35 ± 14 yr; 97 ± 35 kg; 32 + 9% body fat) and 11.67 ± 1.85 MJ/d for the 9 females (31 ± 13 yr; 106 ± 32 kg; 49 ± 6% body fat). Energy intake assessed by 24-hour recall was 13.59 ± 7.81 MJ/d for men and 9.29 ± 2.77 MJ/d for women, compared to 12.84 ± 2.85 and 9.40 ± 2.61 MJ/d for men and women, respectively, by FFQ. Both dietary methods indicated significant underreporting by women when compared to TEE. Energy intake assessed by FFQ was significantly correlated with TEE (r=0.48, p=0.03). This was true with 24-hour recall energy intake only when data from two extremely large alcohol consumers were eliminated (r=0.64, p=0.03, N=19). Although a low level of activity was apparent, the activity questionnaire produced significant correlations with measurements of energy expenditure and therefore represents an important tool for examining the relationship between physical activity and diseases.     

Validity and Reproducibility of a Spanish Dietary History

Objective

To assess the validity and reproducibility of food and nutrient intake estimated with the electronic diet history of ENRICA (DH-E), which collects information on numerous aspects of the Spanish diet.

Methods

The validity of food and nutrient intake was estimated using Pearson correlation coefficients between the DH-E and the mean of seven 24-hour recalls collected every 2 months over the previous year. The reproducibility was estimated using intraclass correlation coefficients between two DH-E made one year apart.

Results

The correlations coefficients between the DH-E and the mean of seven 24-hour recalls for the main food groups were cereals (r = 0.66), meat (r = 0.66), fish (r = 0.42), vegetables (r = 0.62) and fruits (r = 0.44). The mean correlation coefficient for all 15 food groups considered was 0.53. The correlations for macronutrients were: energy (r = 0.76), proteins (r = 0.58), lipids (r = 0.73), saturated fat (r = 0.73), monounsaturated fat (r = 0.59), polyunsaturated fat (r = 0.57), and carbohydrates (r = 0.66). The mean correlation coefficient for all 41 nutrients studied was 0.55. The intraclass correlation coefficient between the two DH-E was greater than 0.40 for most foods and nutrients.

Conclusions

The DH-E shows good validity and reproducibility for estimating usual intake of foods and nutrients.     

Dietary Patterns and Their Associations with Obesity in the Brazilian City of Rio de Janeiro

Objective: To evaluate the dietary patterns of adults living in the city of Rio de Janeiro, Brazil and their associations with body mass index (BMI). Research Methods and Procedures: A survey was conducted in 1996 in a probabilistic sample of 2040 households. Weight and height were measured and food intake was based on an 80-item semi-quantitative food frequency questionnaire. Dietary patterns were identified through factor analysis. Results: More than one-third of the adult population (20 to 60 years old) was overweight (BMI = 25 to 29.9 kg/m²), and 12% were obese (BMI ≥ 30 kg/m²). Three major dietary patterns were identified: mixed pattern when all food groups and items had about the same factor loading, except for rice and beans; one pattern that relies mainly on rice and beans, which was called a traditional diet; and a third pattern, termed a Western diet, where fat (butter and margarine) and added sugar (sodas) showed the highest positive loading and rice and beans were strong negative components. Among men, the Western diet also included deep-fried snacks and milk products with high positive values. The traditional diet was associated with lower risk of overweight/obesity in logistic models adjusted for dieting, age, leisure physical activity, and occupation (13% reduction in men and 14% reduction in women comparing the traditional and Western diets). Discussion: Factors contributing to the effects of the Brazilian traditional diet may include low-energy density, high-dietary fiber content, incorporation of low glycemic index foods such as beans, or a relatively low food variety.     

Rats Eat a Cafeteria-Style Diet to Excess but Eat Smaller Amounts and Less Frequently when Tested with Chow

Background

Obesity is associated with excessive consumption of palatable, energy dense foods. The present study used an animal model to examine feeding patterns during exposure to and withdrawal from these foods.

Methods

Male Sprague Dawley rats were exposed to standard lab chow only (Chow rats) or a range of cafeteria-style foods eaten by people (Caf rats). After 1, 4, 7 and 10 weeks of diet in their home cage, rats were subjected to 24-hour test sessions in a Comprehensive Lab Animal Monitoring System (CLAMS). In the first two test sessions, Chow rats were exposed to standard lab chow only while Caf rats were exposed to a biscuit and high-fat chow diet. In the final two test sessions, half the rats in each group were switched to the opposing diet. In each session we recorded numbers of bouts, energy consumed per bout, and intervals between bouts across the entire 24 hours.

Results

Relative to Chow rats, Caf rats initiated fewer bouts but consumed more energy per bout; however, their motivation to feed in the CLAMS declined over time, which was attributed to reduced variety of foods relative to their home cage diet. This decline in motivation was especially pronounced among Caf rats switched from the palatable CLAMS diet to standard lab chow only: the reduced energy intake in this group was due to a modest decline in bout frequency and a dramatic decline in bout size.

Conclusions

Exposure to a cafeteria-diet, rich in variety, altered feeding patterns, reduced rats'' motivation to consume palatable foods in the absence of variety, and further diminished motivation to feed when palatable foods were withdrawn and replaced with chow. Hence, variety is a key factor in driving excessive consumption of energy dense foods, and therefore, excessive weight gain.     

Relative Validity of Three Food Frequency Questionnaires for Assessing Dietary Intakes of Guatemalan Schoolchildren

ObjectiveTo determine the relative validity of three food frequency questionnaires (FFQs) compared with results from 24-hour dietary recalls for measuring dietary intakes in Guatemalan schoolchildren.DesignA cross-sectional study of primary caregivers (mothers or grandmothers) of 6–11 year-old children. Caregivers completed one of three constructed FFQs to measure the child’s dietary consumption in the last week: FFQ1 did not incorporate portion sizes; FFQ2 provided portion sizes; and FFQ3 incorporated pictures of median portion sizes. During the same week, each caregiver also completed three 24-hour dietary recalls. Results from the FFQ were compared with corresponding results from the 24-hour dietary recalls.SettingSanta Catarina Pinula, peri-urban Guatemala City.SubjectsCaregivers (n = 145) of 6–11 year-old children: 46 completed FFQ1, 49 completed FFQ2, and 50 completed FFQ3.ResultsThe mean values for all nutrients obtained from the 24-hour dietary recall were lower than for those obtained from the FFQs, excluding folic acid in FFQ3, cholesterol and zinc in FFQ2, and cholesterol, folic acid, magnesium, potassium, sodium, and zinc in FFQ1. Energy-adjusted Pearson correlation coefficients ranged from 0.07 (protein) to 0.54 (cholesterol) for FFQ1 and from 0.05 to 0.74 for FFQ2 and FFQ3. Agreement by both methods (FFQ and 24-hour dietary recalls) of classifying children into the same or adjacent quartiles of energy-adjusted nutrient consumption ranged from 62.0% for cholesterol to 95.9% for vitamin B12 across all three FFQs.ConclusionsOur FFQs had moderate to good relative validity in measuring energy and nutrient intakes for 6–11 year-old Guatemalan children. More evidence is needed to evaluate their reproducibility and applicability in similar populations.     

Native Healing in Alaska—Report From Serpentine Hot Springs

Traditional Alaskan Native healing practices, specifically sweat bathing and hot springs bathing, have medical connotations in that they involve sociocultural factors important to practicing medicine among Alaskan Native people. At Serpentine Hot Springs in northwest Alaska, relief for arthritis, back pain, hip pain, headaches, skin rashes and other disorders was sought. The “treatment setting” was an informal bathhouse and bunkhouse and Eskimo tribal doctors and patients were assigned tasks related to healing. Continuity with traditional cultural patterns was achieved in several ways: meals tended to be traditional Eskimo fare, the predominant language spoken was Inupiaq and styles of interaction were Inupiat in character. All patients showed improvement. The experience reported herein is instructive for those seeking innovative approaches treating Native American groups.     

Reproducibility and relative validity of a food frequency questionnaire developed for female adolescents in Suihua, North China

Background

This study aims to evaluate the reproducibility and validity of a food frequency questionnaire (FFQ) developed for female adolescents in the Suihua area of North China. The FFQ was evaluated against the average of 24-hour dietary recalls (24-HRs).

Methodology/Principal Findings

A total of 168 female adolescents aged 12 to 18 completed nine three consecutive 24-HRs (one three consecutive 24 HRs per month) and two FFQs over nine months. The reproducibility of the FFQ was estimated using intraclass correlation coefficients (ICCs), and its relative validity was assessed by comparing it with the 24-HRs. The mean values of the 24-HRs were lower than those of the FFQs, except for protein (in FFQ1) and iron (in FFQ2). The ICCs for all nutrients and food groups in FFQ1 and FFQ2 were moderately correlated (0.4–0.8). However, all the ICCs decreased after adjusting for energy. The weighted κ statistic showed moderate agreement (0.40–0.6) for all nutrients and food groups, except for niacin and calcium, which showed poor agreement (0.35). The relative validity results indicate that the crude Spearman''s correlation coefficients of FFQ1 and the 24-HRs ranged from 0.41 (for Vitamin C) to 0.65 (for fruit). The coefficients of each nutrient and food group in FFQ2 and the 24-HRs were higher than those in FFQ1 and the 24-HRs, indicating good correlation. Although all energy-adjusted Spearman''s correlation coefficients were lower than the crude coefficients, de-attenuation to correct for intra-individual variability improved the correlation coefficients. The weighted κ coefficients of nutrients and food groups ranged from 0.32 for beans to 0.52 for riboflavin in FFQ1 and the 24-HRs, and 0.32 for Vitamin C to 0.54 for riboflavin in FFQ2 and the 24-HRs.

Conclusion

The FFQ developed for female adolescents in the Suihua area is a reliable and valid instrument for ranking individuals within this study.     

Amount of Food Group Variety Consumed in the Diet and Long‐Term Weight Loss Maintenance

Objective: Decreases in variety of foods consumed within high‐fat‐dense food groups and increases in variety of foods consumed within low‐fat‐dense food groups are associated with lower energy intake and greater weight loss during obesity treatment and may assist with weight loss maintenance. This study examined food group variety in 2237 weight loss maintainers in the National Weight Control Registry, who had lost 32.2 ± 18.0 kg (70.9 ± 39.5 lbs) and maintained a weight loss of at least 13.6 kg (30 lbs) for 6.1 ± 7.7 years. Research Methods and Procedures: At entry into the registry, registry members completed a food frequency questionnaire from which amount of variety consumed from different food groups was assessed. To provide a context for interpreting the level of variety occurring in the diet of registry participants, food group variety was compared between registry participants and 96 individuals who had recently participated in a behavioral weight loss program and had lost at least 7% of initial body weight. Results: Registry members reported consuming a diet with very low variety in all food groups, especially in those food groups higher in fat density. Registry participants consumed significantly (p < 0.001) less variety within all food groups, except fruit and combination foods, than recent weight losers after 6 months of weight loss treatment. Discussion: These results suggest that successful weight loss maintainers consume a diet with limited variety in all food groups. Restricting variety within all food groups may help with consuming a low‐energy diet and maintaining long‐term weight loss.     

Poor Nutrition Status and Associated Feeding Practices among HIV-Positive Children in a Food Secure Region in Tanzania: A Call for Tailored Nutrition Training

Undernutrition among HIV-positive children can be ameliorated if they are given adequate foods in the right frequency and diversity. Food insecurity is known to undermine such efforts, but even in food rich areas, people have undernutrition. As yet no study has examined feeding practices and their associations with nutrition status among as HIV-positive children in regions with high food production. We therefore examined the magnitude of undernutrition and its association with feeding practices among HIV-positive children in a high food production region in Tanzania.

Methods

We conducted this mixed-method study among 748 children aged 6 months-14 years attending 9 of a total of 32 care and treatment centers in Tanga region, Tanzania. We collected quantitative data using a standard questionnaire and qualitative data through seven focus group discussions (FGDs).

Results

HIV-positive children had high magnitudes of undernutrition. Stunting, underweight, wasting, and thinness were prevalent among 61.9%, 38.7%, 26.0%, and 21.1% of HIV-positive children, respectively. They also had poor feeding practices: 88.1% were fed at a frequency below the recommendations, and 62.3% had a low level of dietary diversity. Lower feeding frequency was associated with stunting (β = 0.11, p = 0.016); underweight (β = 0.12, p = 0.029); and thinness (β = 0.11, p = 0.026). Lower feeding frequency was associated with low wealth index (β = 0.06, p<0.001), food insecurity (β = −0.05, p<0.001), and caregiver''s education. In the FGDs, participants discussed the causal relationships among the key associations; undernutrition was mainly due to low feeding frequency and dietary diversity. Such poor feeding practices resulted from poor nutrition knowledge, food insecurity, low income, and poverty.

Conclusion

Feeding practices and nutrition status were poor among HIV-positive children even in food rich areas. Improving feeding frequency may help to ameliorate undernutrition. To improve it, tailored interventions should target children of poor households, the food insecure, and caregivers who have received only a low level of education.     

The ecological interdependence of diet and disease in tribal societies.

Observations among nomads suggest there is a strong ecological interdependence of diet and disease in tribal societies which favors survival of man. This relationship may be disrupted by changes in diet to conform to the highly productive technology of the West. Such changes may result in intensification of indigenous disease and in the transfer of disease characteristics of Western societies. To prevent these consequences, relief feeding and long-term attempts to upgrade nutrition should be carried out with traditional foods wherever possible.     

Demographic and socioeconomic determinants of variation in food and nutrient intake in an Andean community

Understanding the sources of variation in a community's diet is vital for development work, as well as being a source of anthropological and cultural insights. Previous surveys in the South American Andes suggest that nutrient deficiencies may be widespread; however, such interpretations have remained tentative since variance in Andean populations' diet has not been thoroughly examined. In this paper we consider the variation in diet due to variation in age, sex, and socioeconomic status and variation attributed to inter- and intraindividual variation in the diet. One to six days of dietary data (mean = 3.1) were collected via 24 h recalls from 221 residents of a small, rural community in highland Ecuador. The contribution of various food groups to the diet varied with land holdings and age but not sex. For example, animal-derived foods contribute more and tubers contribute less to the diet of the households with ≥5 Ha, and sweets contribute more to the diet of children. The interindividual variation in energy and nutrient intake was low and the intraindividual variation high relative to developed countries. The consequence are twofold. First, because interindividual variability is low, group mean intake can be estimated relatively easily, facilitating group comparisons. Second, because intraindividual variation is high, individual nutrient intake cannot be easily estimated, which will decrease the ability to detect associations between nutrient intake and health measures. This knowledge of the sources of dietary variation can lead to better study and survey designs in the rural Andes and elsewhere in the developing world. Am J Phys Anthropol 105:407–417, 1998. © 1998 Wiley-Liss, Inc.     

Diets in Transition: Hunter-Gatherer to Station Diet and Station Diet to the Self-Select Store Diet

The transition of Australian Aborigines from a diet based on hunting and gathering to an essentially Western diet has been proceeding for almost 200 years, but in some regions was greatly delayed. In 1966/1967 G ould (1980) studied operational aspects of hunting-gathering in desert regions of northwestern Australia and recorded sufficient quantitative and species-specific data to allow definition of the diet over 5 months. By 1966, many Aboriginal people in that region had been displaced from their hunting grounds and were living in camps on cattle stations or in missions. Aboriginal diet on cattle stations in the north-westwas studied in 1951 (Commonwealth Departmentof Health) and shown to consist chiefly of fresh meat, wheaten flour, and sugar with small amounts of vegetables and dairy products. With the granting of citizenship in 1967, most Aborigines were dismissed from cattle stations and were moved first to town camps and later formed remote Aboriginal communities. Studies in the 1980s showed that the self-selected diet in such communities reflected the station diet to a greater extent than the traditional diet. Quantitative presentation of the above three diets, in terms both of foods and of major nutrients, show that many of the dietary inadequacies of the station diet identified in 1951 still persisted in self-selected Aboriginal diets in the 1980s. A comparison of the three diets with a modern recommended dietsupports the nutritional adequacy of the hunter-gatherer diet. Traditional cultural values assigned to food preferences continued to influence food choices in all three diets.     

Observations on the ontogeny of feeding behavior in mountain gorillas (Gorilla gorilla beringei)

This report describes observations on the ontogeny of food choice in mountain gorillas (Gorilla gorilla beringei), made during a 17-month field study of mountain gorilla feeding ecology in the Parc National des Volcans, Rwanda. Data are presented on the feeding behavior of two infants observed from birth to the age of 8 months and on older infants and juveniles. This information is compared with data on the composition and diversity of the diets of young adults and adults in the same social group. Initial feeding by infants is usually synchronized with the mother's behavior: infants ingest the same food, or a different part of the same plant species, currently being eaten by the mother or just eaten by her. This suggests that observational learning is largely responsible for the transmission of food preferences. Most feeding by young infants, whether or not synchronized with the mother's, is on those foods eaten most frequently by adults. Infants also independently sample potential foods, some of which are apparently not consumed by adults. The frequency of sampling declines with age, although even adults occasionally ingest foods not observed to be eaten by other adults. By the age of 3 years, young mountain gorillas have developed the basic dietary patterns of adults, in terms of the number of foods eaten, the proportions in which specific foods are consumed, and diet diversity and equitability. There is a strong possibility that chemical cues influence food choice, but their role remains unclear.     

Methods for Assessment of Dietary Lead Exposure of the Inner-City Population

Abstract

Assessment of dietary lead exposure of individuals begins with the determination of food and beverage intake by the individuals, and concludes with an evaluation of the lead content of the foods and beverages consumed. Of several techniques available for assessment of dietary intake, the 24-hour food recall is recommended as the method of choice for assessing current dietary lead intakes in inner-city populations. The three-day food record can be used among cooperative and motivated subjects, while the dietary history method is available for assessing long-term intakes in the past. The unavailability of lead content values of a large number of foods will to a large extent restrict the use of these methods in large-scale dietary lead exposure studies. Until the time that such data becomes available, the most accurate estimates of lead intake can be provided by chemical analysis of duplicate samples of foods consumed, as is currently done. However, this method is feasible only for small samples.