Social desirability bias in dietary self-report may compromise the validity of dietary intake measures

BACKGROUND: Self-report of dietary intake could be biased by social desirability or social approval thus affecting risk estimates in epidemiological studies. These constructs produce response set biases, which are evident when testing in domains characterized by easily recognizable correct or desirable responses. Given the social and psychological value ascribed to diet, assessment methodologies used most commonly in epidemiological studies are particularly vulnerable to these biases. METHODS: Social desirability and social approval biases were tested by comparing nutrient scores derived from multiple 24-hour diet recalls (24HR) on seven randomly assigned days with those from two 7-day diet recalls (7DDR) (similar in some respects to commonly used food frequency questionnaires), one administered at the beginning of the test period (pre) and one at the end (post). Statistical analysis included correlation and multiple linear regression. RESULTS: Cross-sectionally, no relationships between social approval score and the nutritional variables existed. Social desirability score was negatively correlated with most nutritional variables. In linear regression analysis, social desirability score produced a large downward bias in nutrient estimation in the 7DDR relative to the 24HR. For total energy, this bias equalled about 50 kcal/point on the social desirability scale or about 450 kcal over its interquartile range. The bias was approximately twice as large for women as for men and only about half as large in the post measures. Individuals having the highest 24HR-derived fat and total energy intake scores had the largest downward bias due to social desirability. CONCLUSIONS: We observed a large downward bias in reporting food intake related to social desirability score. These results are consistent with the theoretical constructs on which the hypothesis is based. The effect of social desirability bias is discussed in terms of its influence on epidemiological estimates of effect. Suggestions are made for future work aimed at improving dietary assessment methodologies and adjusting risk estimates for this bias.     

Development and testing of a seven-day dietary recall. Dietary Assessment Working Group of the Worcester Area Trial for Counseling in Hyperlipidemia (WATCH)

Using multiple 24-hr recalls (24HR) we tested the Seven Day Dietary Recall (7DDR) developed to assess nutrient exposures, especially lipids, in dietary interventions and other clinical trials requiring measurement of effect over moderate time periods. A total of 261 individuals in three studies completed a 7DDR at the end of a 3- to 5-week period during which 3 to 7 24HR were telephone-administered on randomly selected days. One of these studies and data from one additional study (total n = 678) allowed us to test the ability of the 7DDR to predict serum lipid changes in an intervention setting. In correlation and linear regression analyses, high levels of agreement between 7DDR and 24HR were obtained. For total energy: r = 0.67 and b = 0.69, and for total fat intake (g/day): r = 0.67 and b = 0.80. When 7 days of 24HR were available agreement tended to be higher. For total energy: r = 0.69 and b = 0.95, and for total fat (g/day): r = 0.71 and b = 1.04. Data derived from the 7DDR and fit to the Keys and Hegsted equations closely predicted actual changes in total serum cholesterol (within 15% and 10%, respectively). The 7DDR is a relatively easily administered, sensitive method to assess short-term changes in dietary fat consumption in individuals.     

The Chinese total diet study in 1990. Part II. Nutrients

This paper reports the intakes of 72 nutrients and their dietary sources obtained from the Chinese total diet study in 1990. Most of the nutrient intakes are close or equal to their corresponding recommended daily allowances (RDAs). Both the total energy intake (2203 kcal) and the proportions contributed by protein, fat, and carbohydrate meet the current Chinese RDAs and the World Health Organization (WHO) nutrient goals. The average protein intake was 64 g/day. The intake of essential amino acids all exceeded the Chinese RDA, and their proportions were generally consistent with the WHO recommended pattern. The average fat intake was 51.2 g/day (21.2% of the total energy intake). However, the dietary fat intake has been increasing significantly in the Chinese diet and the proportion of animal fat has reached 53% of the total fat intake. The total saturated:total monounsaturated: total polyunsaturated fatty acid ratio was 1.0:1.5:1.0. Although the average cholesterol intake was only 179 mg/day, it was 248 mg/day in the South 1 region. The intakes of thiamine and riboflavin were below the RDA. Retinol intakes in all the 4 regions were low. Most (80%) of the retinol (equivalent) intakes were from carotenoids. The average intake of total tocopherol was 89% of the RDA, and among the 4 regions, only the South 2 region has relatively low intake. The intakes of iron, copper, manganese, sodium, and phosphorus were adequate. The intakes of calcium, zinc, and potassium were insufficient, and intakes of selenium and magnesium were a little low. High sodium and low potassium intake is a traditional problem in the Chinese diet.     

Effect of energy density and fat level of milk formulas on subsequent food and energy intake in preschool children

The aim of this study was to examine the effects of two levels of energy intakes and two levels of fat at breakfast, on the food and energy intakes in subsequent meal (lunch). The study was performed in 51 children both genders, with ages ranging from 24 to 48 months, attending a day care center. The children selected had normal nutritional status (weight/height index) according to the NCHS standards. The food intake was determined by differential weighing and energy intake was calculated from proximal analysis. The energy densities of the cow's milk formula used were 0.8 and 1.2 kcal/g, resulting in a total energy offer (breakfast) of 267.5 and 367.5 kcal respectively, the fat levels were 6.3 and 0.9 g/250 g of formula, using the design 2 x 2 factorial. In the study, 720 observations of food intake were conducted in those children consuming higher than 75% of the total food offered at breakfast. In the lunch-time were offered in alternated form two preparations with an 0.97 kcal/g of energy density. The results demonstrated that the children consumed significantly higher energy amounts in the subsequent meal, after being fed the high fat and lower energy-content breakfast. When the total energy intake (breakfast + lunch) was compared these results show that the caloric difference of breakfast was reduced and the degree of reduction was influenced by the fat level. These results show evidence for partial caloric compensation of 67% in the higher-fat level, and only 34% for the children with the lower of fat-level. It is conclude that the energy intake and fat intake at breakfast influences the energy intake at the subsequent meal. These findings are important to the preschool children's feeding with risk of malnutrition.     

Effect of exercise and dietary restraint on energy intake of reduced-obese women

Self-selected food intake of 15 reduced-obese women living in a metabolic ward was studied for 14 consecutive days to determine the effect of exercise and other metabolic and behavioral variables on energy intake. A choice of prepared food items were offered at breakfast, lunch and dinner, and a variety of additional food items were available continuously 24 h/day. Subjects performed either moderate intensity aerobic exercise (A-EX) (n = 8) expending 354 +/- 76 kcal/session or low intensity resistance weight training (R-EX)(n =7) expending 96 +/- kcal/session, 5 days/week. Mean energy intakes (kcal/day, +/- SEM) of the exercise groups were similar: 1867 +/- 275 for A-EX, 1889 +/- 294 for R-EX. Mean energy intakes of individuals ranged from 49 to 157% of the predetermined level required for weight maintenance. Resting metabolic rate per kg 0.75 and the Eating Inventory hunger score contributed significantly to the between subject variance in energy intake, whereas exercise energy expenditure did not. Regardless of exercise, eight women consistently restricted their energy intake (undereaters), and seven other consumed excess energy (overeaters). Overeaters were distinguished by higher Eating Inventory disinhibition (P = 0.023) and hunger (p = 0.004) scores. The overeaters' diet had a higher fat content 34 +/- 1% (p = 0.007). Also, overeaters took a larger percentage of their daily energy, than that of undereaters, 27 +/- 1 energy intake in the evening, 13 +/- 2%, compared to undereaters, 7 +/- 1% (p = 0.005). We conclude that the Eating Inventory is useful for identifying reduced-obese women at risk of overeating, and these individuals may benefit from dietary counseling aimed at reducing fat intake and evening snacking.     

Treatment of varicocele for male infertility: a comparative study evaluating currently used approaches

It has been stated that energy adjustment can control for recall bias in case-control studies. Simulation of recall bias and cases and controls in a nutritional survey of German adults was conducted to examine its impact on five dietary effects, (adding a macronutrient, substituting one macronutrient for another, adding a macronutrient while keeping the other energy sources constant, and changing the macronutrient to energy ratio through addition or substitution) using various energy adjustment models. If energy adjustment were an effective means of correcting measurement error, the energy adjusted dietary effects, after a subtraction of energy and fat intake, should equal those in the original data set. Simulation of differential under-reporting of fat and energy intake by cases but not controls showed this to dramatically impact all five considered dietary effects, even after energy adjustment. The influence of the assumed recall bias on the different effects depends on the error type structure, inflating an odds ration of 1.8 to as much as 12.3 or reducing it to 0.45 when 100 kcal of fat was substituted for 100 kcal of other macronutrients. Although energy adjustment may serve many functions, it cannot correct for differential error. Depending upon the nature of the hypothesized effect and the error type, energy adjustment may also distort risk ratios in the presence of non-differential bias. The concern that cases and controls report their energy intakes with different degrees of error remains a critical consideration that must be addressed through improved measurements, and not energy adjustment under any of the currently used models.     

Effects of carbontetrachloride and chenodeoxycholic acid on hepatic monooxygenase system, lipid peroxidation and some immunologic parameters in rats

BACKGROUND: Nutritional characteristics of the mediterranean diet, with a high intake of complex carbohydrates, fibre, monounsatured fatty acids and vegetables, are related to a lower prevalence of some nutritional associated diseases. The aim of our study was to perform a longitudinal analysis of the evolution of food intake in a mediterranean population in order to observe its influence on the energy and nutritional intake and their balance. The latter could have some effects on health status. METHODS: Dietary intake was evaluated using the 24 hours recall method in a representative sample (n = 941, age range = 10-69) of a Reus population. This longitudinal study consisted of 70% of the samples studied in 1983 using identical methodology. RESULTS: During this decade (1983-1993), energy intake decreased significantly 180 kcal/day for men and 158 kcal/day for women, carbohydrates being the main cause for this drop (132 and 84 kcal/day less for men and women, respectively). Protein intake decreased significantly in both sexes, 5.6% for men and 8.0% for women. However, the evolution of fat intake was different for men (no changes) and for women (a significant decrease of 5.7%). Saturated and monounsatured fatty acids did not show significant changes in this decade. Cholesterol intake decreased significantly in both sexes. Energy percents obtained from lipids, saturated and monounsaturated fatty acids significantly increased. However, in absolute values very little changes in fat intake in both sexes were observed. CONCLUSIONS: The dietary pattern evolved to a lower energy intake with an increment of the percentage of dietary lipids, but this feature was did not reflect a greater fat intake in absolute values. Moreover, the main characteristics of the typical mediterranean diet (which is basically different to the usual diet of other non mediterranean european countries mainly due to its richness in monounsaturated fatty acids) did not change in the period analyzed.     

Monitoring dietary change in a low-fat diet intervention study: advantages of using 24-hour dietary recalls vs food records

OBJECTIVE: The purpose of the study was to evaluate two methods of dietary assessment for monitoring change in fat intake in a low-fat diet intervention study. DESIGN: The two dietary assessment methods were a 4-day food record (4DFR) and an unannounced 24-hour dietary recall conducted by telephone interview (referred to as a telephone recall [TR]). Subjects were assigned randomly to either a low-fat diet intervention group or a control group that received no counseling about fat intake. Dietary data were collected at baseline, 6 months, and 12 months. SUBJECTS: Two hundred ninety postmenopausal women with localized breast cancer were recruited at seven clinical centers in the United States. STATISTICAL ANALYSIS: Analysis of variance was used to test for significant differences in mean fat and energy intakes. RESULTS: Three sources of error were identified: (a) an instrument effect, suggesting underreporting at baseline of approximately 8% in mean energy intake and 11% in mean fat intake in the TR group compared with the 4DFR group (P = .0001); (b) a repeated measures effect observed for the 4DFR, suggesting underreporting of approximately 7% for energy intake and 14% for fat intake in the control group at 6 and 12 months compared with baseline values (P < .001); and (c) an adherence effect (or compliance bias), suggesting greater compliance to the low-fat intervention diet when subjects were keeping food records than when estimates were based on the unannounced TR. Compared with the TR, the 4DFR overestimated the extent of fat reduction in the low-fat diet intervention group by 41% (P = .08) and 25% (P = .62) at 6 and 12 months, respectively. APPLICATION: Multiple days of unannounced 24-hour recalls may be preferable to multiple-day food records for monitoring dietary change in diet intervention studies.     

Estimates of food and macronutrient intake in a random sample of Northern Ireland adolescents

Estimates of food consumption and macronutrient intake were obtained from a randomly selected population sample (2%) of 1015 adolescents aged 12 and 15 years in Northern Ireland during the 1990/1991 school year. Dietary intake was assessed by diet history with photographic album to estimate portion size. Reported median energy intakes were 11.0 and 13.1 MJ/d for boys aged 12 and 15 years respectively and 9.2 and 9.1 MJ/d for girls of these ages. Protein, carbohydrate and total sugars intakes as a percentage of total energy varied little between the age and sex groups and were approximately 11, 49 and 20% respectively of daily total energy intakes. Median dietary fibre intakes were approximately 20 and 24 g/d for boys aged 12 and 15 years respectively and 18 and 19 g/d for girls of these ages. Major food sources of energy (as a percentage of total energy intakes) were bread and cereals (15-18%), cakes and biscuits (12-14%), chips and crisps (13-14%), dairy products (9-11%), meat and meat products (9-11%) and confectionery (9%). Fruit and vegetable intakes were low at about 2.5% and 1.5% respectively of total energy intakes. Median fat intakes were high at 39% of total daily energy intakes. Major food sources of fat as a percentage of total fat intakes were from the food groupings: chips and crisps (16-19%), meat and meat products (14-17%), fats and oils (14-16%), cakes and biscuits (13-16%) and dairy products (12-15%). Median intakes of saturated fatty acids were also high at approximately 15% of daily total energy intake while intakes of monounsaturated fatty acids averaged 12% of daily total energy intake. Median polyunsaturated fatty acid (PUFA) intakes were low, comprising 5.2 and 5.5% of daily total energy intake for boys aged 12 and 15 years respectively and were lower than the PUFA intakes (5.9 and 6.3% of daily total energy intake) for girls of these ages. About 1.3% for boys and 1.4% for girls of daily total energy intake was in the form of n-3 PUFA. Ca and Mg intakes were adequate for both sexes. Based on these results, some concern about the dietary habits and related health consequences in Northern Ireland adolescents appears justified.     

Low dietary fiber and high protein intakes associated with newly diagnosed diabetes in a remote aboriginal community

The high prevalence of diabetes mellitus in North American aboriginal populations may be due to recent changes in lifestyle, including the adoption of a high-fat, low-fiber diet. To determine whether fat or fiber intakes were associated with new cases of diabetes, we studied 72% (728/1018) of residents aged > 9 y from a remote aboriginal community in northern Ontario using the 75-g oral-glucose-tolerance test and 24-h dietary recall. The mean fat intake of this population (36% of energy) was typical for North America, but fiber intake (1.2 g/MJ) was very low. Logistic-regression analysis, adjusted for age, sex, and body mass index, showed that a 1-SD increase in fiber intake reduced the risk of having diabetes by 39% (P = 0.026) whereas the same increase in protein intake increased the risk by 38% (P = 0.027). There was no significant effect of energy, fat, starch, or simple sugars. These data support Trowell's original dietary-fiber hypothesis that "... dietary fiber depleted starchy foods are conducive to the development of diabetes mellitus in susceptible human genotypes."     

Effect of high-fat and low-fat diets on voluntary energy intake and substrate oxidation: studies in identical twins consuming diets matched for energy density, fiber, and palatability

There remains controversy over the effects of dietary fat content on voluntary energy intake. Additionally, the question of whether there is a genetic susceptibility to overeating high-fat diets has not been resolved. To address these issues, we designed two diets: a low-fat diet providing approximately 20% of energy as fat and a high-fat diet with approximately 40% of energy as fat. The diets were matched for energy density, fiber, and palatability. In a two-phase, 18-d intervention study, voluntary energy intakes and macronutrient oxidation rates during the fasting and fed states were determined in seven pairs of identical male twins. In contrast with results of previous intervention studies, in which low-fat and high-fat diets were not matched for energy density and other associated variables, we observed no significant difference in voluntary energy intake between the low-fat and high-fat phases, and mean daily intakes were similar (10.3 and 10.7 MJ/d, respectively). Postprandial rates of fat oxidation tended to reflect fat intakes in the two dietary phases, thus helping to explain the lack of a difference in mean energy intakes. There was also a significant twin-pair similarity in differences in energy intakes between dietary phases (P = 0.013). These results suggest that dietary fat content does not have a major influence on voluntary energy intake when dietary variables usually associated with fat are controlled for and that there may be a familial influence on the effects of dietary fat content on energy intake.     

Measurement of blood loss and bleeding pattern from the bleeding time incision

Intervention studies have shown that the adaptation of fat oxidation to fat intake, when changing the dietary fat content, is not abrupt. This study was conducted to measure the time course of adaptation of oxidation rates to increases in the fat content of the diet, when feeding subjects at energy balance. Twelve healthy, non-obese males and females (age: 26 +/- 2, BMI: 21.4 +/- 0.5, habitual fat intake: 29 +/- 1% energy) consumed a low-fat diet for 6 days (days 1-6) followed by a high-fat diet for 7 days (day 7-13). Days 5-9 and day 13 were spent in a respiration chamber. After adjusting energy intake to 24h energy expenditure on day 5, subjects were in energy balance (range -0.15 to +0.23 kJ/day) on days 6-9 and day 13. Fat balance was zero on day 6 but became positive after changing to the high-fat diet (1.06 +/- 0.15, 0.75 +/- 0.15, and 0.55 +/- 0.14 MJ/day for days 7, 8, and 9 respectively, p. < 0.05), reaching a new balance on day 13, 7 days afterwards. Thus, in case of energy balance, lean subjects are capable of adjusting fat oxidation to fat intake within 7 days, when dietary fat content is increased.     

Changes in dietary fat intake preceding the diagnosis of cancer

We studied changes in dietary fat intake preceding the diagnosis of cancer in 96 men diagnosed with cancer during the Coronary Primary Prevention Trial and Post-trial Follow-up. Diet was assessed semiannually by 24-hour recall for the duration of the trial. Dietary fat intake was elevated in the interval 12-24 months before diagnosis compared with the interval 24-36 months before diagnosis [6.9 gm per day; 95% confidence interval (CI) = 0.04-13.7]. The percentage of calories as fat was also elevated (1.9%; 95% CI = 0.34-3.4). Fat consumption decreased in the 0- to 12-month prediagnostic interval. The basis for the elevation is unclear, but it may have been due to the metabolic effects of cancer before its diagnosis. Case-control studies of long-term diet may overestimate positive associations between dietary fat and cancer risk if the cases' recall includes the prediagnostic period, during which fat intake is elevated. In analyses of prospective studies of dietary fat and cancer, data from within the first 2-3 years of baseline should be examined separately to evaluate the potential for bias introduced by the inclusion of measurements representing transient elevations in dietary fat intake.     

Decrease in insulin and insulin-like growth factor I (IGF-I) binding to erythrocytes from patients with cystic fibrosis

Guidelines for a healthy diet often recommend limiting dietary sugars and fats. Some researchers have called these aims mutually incompatible, suggesting that fat and sugar intakes, when expressed as percent dietary energy, are inversely linked. Others have argued that sugar, more specifically sucrose, acts as a vehicle for dietary fat and serves to suppress the overall quality of the diet. This study examined the relationship between age, sucrose and fat intakes, body mass index (BMI), and measures of dietary diversity and variety in a community-based sample of 837 French adults. Consistent with other studies, high consumption of added sucrose (in g/day or g/1000 kcal per day) was associated with higher consumption of energy and fat and lower consumption of vegetables and fruit. However, eating patterns were strongly influenced by age. High-sucrose consumers were significantly younger and had lower BMI values than did low-sucrose consumers, who were both older and had higher BMIs. High-sucrose diets had minimal effect on the diet diversity score and were associated with more varied diets, as evidenced by a higher dietary variety score.     

Inverse association of dietary fat with development of ischemic stroke in men

CONTEXT: A few ecological and cohort studies in Asian populations suggest an inverse association of the intake of both fat and saturated fat with risk of stroke. However, data among western populations are scant. OBJECTIVE: To examine the association of stroke incidence with intake of fat and type of fat among middle-aged US men during 20 years of follow-up. DESIGN AND SETTING: The Framingham Heart Study, a population-based cohort study. PARTICIPANTS: A total of 832 men, aged 45 through 65 years, who were free of cardiovascular disease at baseline (1966-1969). MEASUREMENTS AND DATA ANALYSIS: The diet of each subject was assessed at baseline by a single 24-hour dietary recall, from which intakes of energy and macronutrients were estimated. In Kaplan-Meier analyses, we calculated age-adjusted cumulative incidence rates of stroke. Using Cox regression, we estimated stroke incidence relative risks during 20 years of follow-up. MAIN OUTCOME MEASURE: Incidence of ischemic stroke, which occurred in 61 subjects during the follow-up period. RESULTS: Mean intakes were 10975 kJ for energy; 114 g (39% of energy) for total fat; 44 g (15%) for saturated fat; 46 g (16%) for monounsaturated fat; and 16 g (5%) for polyunsaturated fat. Risk of ischemic stroke declined across the increasing quintile of total fat (log-rank trend P=.008), saturated fat (P=.002), and monounsaturated fat (P=.008) but not polyunsaturated fat (P=.33). The age- and energy-adjusted relative risk for each increment of 3% of energy from total fat was 0.85 (95% confidence interval [CI], 0.78-0.94); for an increment of 1% from saturated fat, 0.91 (95% CI, 0.85-0.98); and for 1% from monounsaturated fat, 0.89 (95% CI, 0.83-0.96). Adjustment for cigarette smoking, glucose intolerance, body mass index, blood pressure, blood cholesterol level, physical activity, and intake of vegetables and fruits and alcohol did not materially change the results. Too few cases of hemorrhagic stroke (n=14) occurred to draw inferences. CONCLUSION: Intakes of fat, saturated fat, and monounsaturated fat were associated with reduced risk of ischemic stroke in men.     

Dietary assessment in Whitehall II: the influence of reporting bias on apparent socioeconomic variation in nutrient intakes

OBJECTIVE: To assess socio-economic differences in nutrient intake, giving particular consideration to the influence of reporting bias. DESIGN: Cross-sectional study. Three methods of data analysis (inclusion of all subjects, exclusion of low energy reporters, and regression-based energy adjustment) were evaluated against biomarkers of fatty acid and antioxidant intakes. SETTING: London-based Civil Servants. SUBJECTS: Age and employment grade stratified random sub-sample of 459 men and 406 women aged 39-61 y who completed 7 d diet diaries at Phase 3 follow-up (1991-93) of the Whitehall II Study. DIETARY MEASURES: Mean daily intakes by employment grade (6 levels) of dietary energy, total fat, saturated fatty acids, polyunsaturated fatty acids (PUFA), linoleic acid, carbohydrate excluding fibre, dietary fibre, protein, alcohol, vitamin C, vitamin E, carotenes, potassium and calcium. Biomarkers: serum cholesterol ester fatty acids (CEFA), total cholesterol, plasma alpha-tocopherol and beta-carotene. RESULTS: Low energy reporting (LER), defined as a reported energy intake below 1.2 times calculated basal metabolic rate, was strongly associated with employment grade (top grade: men 17.3%, women 19.3%, bottom grade: men 45.7%, women 49.2% trend P < 0.0001 both sexes). This association is only to a small extent accounted for by the relative weight distribution across grades. The direct associations with grade--high status, high intakes--of total fat, saturated and polyunsaturated fatty acids seen in the results overall were greatly reduced or abolished when LER were excluded or when energy adjustment was used. Direct associations between grade and intakes of vitamin C and potassium in both sexes were evident regardless of data presentation method. Spearman correlations between biomarkers and reported intakes, for example CEFA and dietary linoleate (men 0.46, women 0.61), plasma beta-carotene/cholesterol ratio and dietary carotenes (men 0.16, women 0.21) together with theoretical considerations indicate that energy adjustment may be the preferred method for reducing the influence of reporting bias. CONCLUSIONS: Low energy reporting is a major source of bias in dietary surveys and its prevalence shows a marked inverse association with socio-economic status. The energy adjustment method provides an approach which reduces this bias without exclusion of low energy reporters. Intakes of micronutrients including vitamin C, rather than fatty acids, showed associations with socio-economic status consistent with a dietary explanation for social inequalities in cardiovascular disease.     

Complex formation of the nonstructural protein 3 of hepatitis C virus with the p53 tumor suppressor

BACKGROUND: Length of survival of females with cystic fibrosis is worse than it is in males. Results of current research have shown an important correlation among dietary intake, nutritional status, lung function, and survival. The purpose of this study was to explore gender differences in dietary intake and pancreatic enzyme replacement therapy in males and females with cystic fibrosis. METHODS: The study was a cross-sectional measurement of clinical characteristics, energy, and fat intakes in males and females attending the cystic fibrosis outpatients clinics of the John Hunter Hospital, Newcastle, Australia. Twenty-nine subjects, (17 females and 12 males), completed 4-day weighed food records to measure total energy intake and the contribution of macronutrients and to document use of pancreatic enzyme replacement therapy. Energy intake was assessed as the percentage of the recommended energy intake for age and sex. RESULTS: Females with cystic fibrosis had significantly lower energy and fat intakes than males, whereas the females used significantly more pancreatic enzyme replacement therapy. There were no significant differences in clinical characteristics between groups. CONCLUSION: The results support the possibility that gender differences in the energy and fat intakes of older patients may contribute to differential median survival time of males and females with cystic fibrosis.     

Survey of the diet of Pima Indians using quantitative food frequency assessment and 24-hour recall. Diabetic Renal Disease Study

OBJECTIVE: A dietary survey was conducted in the Gila River Indian Community in Arizona using two methods of dietary assessment--24-hour recall and quantitative food frequency (QFF) assessment--to determine the usual intake of the population. DESIGN: Interviews were conducted by Pima women who were trained and monitored by a research dietitian. Energy and nutrient intake were calculated using a computerized dietary database that included specific Pima foods. SUBJECTS: An age- and sex-stratified sample of 575 Pima Indians (273 men, 302 women) aged 18 to 74 years participated in the study. STATISTICAL ANALYSES: Spearman correlations were used to compare the results of the two survey methods for energy and each nutrient. Intraclass correlations were used to measure reproducibility. RESULTS: According to the 24-hour recall, mean reported energy intakes within decades of age were 95% to 112% of those in the US population for Pima women, and 76% to 94% of those in the US population for Pima men. Total energy intake assessed using QFF was 30% higher in men and 33% higher in women than the intake assessed using the 24-hour recall method. CONCLUSIONS: A large dietary survey conducted using lay interviewers in a Native-American community was as reproducible as studies conducted in the general US population. The Pima diet was distributed among the major nutrients in a proportion similar to the US diet.