Comparison of energy intakes determined by food records and doubly labeled water in women participating in a dietary-intervention trial

Dietary Patterns of Healthy Underweight Individuals Compared to Normal-BMI Individuals Using Photographic Food Diaries

BACKGROUND

Previously, we found that healthy underweight (HU) subjects, with BMI < 18.5, eat about 12% less food (by calories) each day. It is presently unclear whether this lower intake is associated with them making food choices that provide high satiation and satiety.

METHODS

Using 7-day photographic records of food intake, we analyzed 52 HU and 50 normal-weight participants.

RESULTS

We included 52 HU and 50 normal-weight participants in the final analysis. HU individuals ate 25% fewer calories than normal-weight individuals. Their intake included a higher % of rice (p = 0.0013) and vegetables (p = 0.0006) and a lower % of livestock meat (p = 0.0007), poultry meat (p < 0.0001), and starchy roots (p = 0.0015), compared with the normal-weight population. The percent energy from carbohydrates was significantly higher (p = 0.0234), and the % energy from fat was significantly lower (p < 0.0001) in the HU group, with no difference in the % energy from protein. HU individuals sourced more of their protein from plants. Dietary patterns were grouped into three clusters, with 24 individuals grouped into cluster 1 (87.5% normal-weight population), 28 individuals into cluster 2 (64.3% normal-weight group), and 50 individuals into cluster 3 (78% HU group).

CONCLUSIONS

The HU group ate less overall and had proportionally more rice and vegetables and less poultry and livestock meat, starchy roots, and drinks. With respect to macronutrients, they also ate a greater % carbohydrates and less % fat, and they sourced more of their protein intake from plant sources. HU individuals did not follow a low-carbohydrate lifestyle.

A Study on the Compatibility of a Food-Recording Application with Questionnaire-Based Methods in Healthy Japanese Individuals

In Japan, nutritional guidance based on food-recording apps and food frequency questionnaires (FFQs) is becoming popular. However, it is not always recognized that different dietary assessment methods have different nutritional values. Here, we compared the compatibility of dietary intake data obtained from an app with those obtained from FFQs in 59 healthy individuals who recorded information regarding their diet for at least 7 days per month using an app developed by Asken (Tokyo, Japan). The diurnal coefficient of variation in total energy and protein intake was 20%, but those for vitamins B12 and D were >80%, reflecting the importance of 7 days of recording rather than a single day of recording for dietary intake analyses. Then, we compared the results of two FFQs-one based on food groups and one based on a brief self-administered diet history questionnaire-for 7 days, as recorded by the app. There was a correlation coefficient of >0.4 for all the items except salt. Regarding the compatibility between the app and FFQs, the percentage errors for total energy and nutrients were >40-50%, suggesting no agreement between the app and the two FFQs. In conclusion, careful attention should be paid to the impact of different dietary assessment methods on nutrient assessment.

A short education session increases the accuracy of estimated food records in young Korean women during a controlled-feeding study

BACKGROUND/OBJECTIVES

Despite the widespread use of dietary assessment tools, the validity of food records has not been evaluated in Koreans. We assessed the accuracy of estimated food records and the effect of a short education session in young Korean women.

SUBJECTS/METHODS

Thirty women (aged 18–23 yrs) each completed 3 food records during a controlled-feeding study. One educational session was provided on day 2 of the study. Food records were analyzed for the accuracy of food items and portion size estimation according to food group (grains; meat, fish, eggs, and beans; vegetables; fruit; dairy; and oils and sugars) and type of dish (rice, kimchi, soup, side dishes, spreads, beverages, and snacks). Reported food items were categorized as exact, close, or far matches, exclusions, or intrusions. Portion sizes were evaluated as accurate, similar, or inaccurate estimates, or missing. The means of days 2 and 3 were used to assess post-education results. Paired t-tests were performed to assess the effects of the education session.

RESULTS

The mean percentages of exact matches, close matches, far matches, and exclusions on day 1 were 80.9%, 10.9%, 2.0%, and 6.2%, respectively, and mean intrusions observed were 0.1. The education session slightly increased the accuracy of recorded food items. The percentages of accurate, similar, and inaccurate estimates, and missing portion sizes were 11.7%, 19.8%, 12.2%, and 56.3%, respectively, at baseline. The percentage of missing portion size estimates decreased to 14.0% after the education session, resulting in an increase in the percentages of all other estimates. An increase was observed in the accuracy of reported portion sizes of vegetables, rice, and kimchi.

CONCLUSIONS

In young Korean women, estimated food records are highly accurate for food items but not for portion size estimates without prior education. A short education session can improve the accuracy of portion size estimation.

Trial Registration

Clinical Research Information Service Identifier: KCT0003307

The effect on satiety of ingesting isosweet and isoenergetic sucrose- and isomaltulose-sweetened beverages: a randomised crossover trial

Generating feelings of satiety may be important in maintaining weight control. It has been hypothesised that the circulating concentration of glucose is a major determinant of satiety, yet the relationship between postprandial glycaemia and satiety is inconclusive. Our aim was to assess satiety following ingestion of beverages differing in glycaemic index (GI) containing either 50 g of sucrose (GI 65) or isomaltulose (PalatinoseTM) (GI 32). The beverages were matched for sweetness using a triangle sensory test. Seventy-seven participants were randomised to the order in which they received each beverage, 2 weeks apart. A standard lunch was given at 12.00 hours. Satiety was measured using 100-mm visual analogue scales (VAS) administered at 14.00 hours (baseline) and at 30, 60, 90, 120, 150 and 180 min after ingesting the beverage. Weighed diet records were kept from 17.00 to 24.00 hours. Mean differences for isomaltulose compared with sucrose AUC VAS were ‘How hungry do you feel?’ 109 (95 % CI –443, 661) mm × min; ‘How satisfied do you feel?’ 29 (95 % CI –569, 627) mm × min; ‘How full do you feel?’ −91 (95 % CI –725, 544) mm × min and ‘How much do you think you can eat?’ 300 (95 % CI –318, 919) mm × min. There was no between-treatment difference in satiety question responses or in dietary energy intake −291 (95 % CI −845, 267) kJ over the remainder of the day. In this experiment, feelings of satiety were independent of the GI of the test beverages. Any differences in satiety found between foods chosen on the basis of GI could be attributable to food properties other than the glycaemic-inducing potential of the food.

Effect of time restricted feeding on the gut microbiome in adults with obesity: A pilot study

BACKGROUND

Time restricted feeding is a form of intermittent fasting where participants shorten the daily window in which they eat.

AIM

This is the first study to examine the effects of intermittent fasting on changes in the gut microbiome.

METHODS

Adults with obesity (n = 14) participated in a daily 8-hour time restricted feeding intervention (8-hour feeding window/16-hour fasting window) for 12 weeks. Fecal microbiota were determined by 16 S rRNA (ribosomal ribonucleic acid) gene sequencing of stool samples.

RESULTS

Body weight decreased (P < 0.05) by -2 ± 1 kg. Gut microbiota phylogenetic diversity remained unchanged. The two most common phyla were Firmicutes and Bacteroidetes accounting for 61.2% and 26.9% of total abundance at baseline. No significant alterations in the abundance of Firmicutes, Bacteroidetes, or any other phyla were detected after 12 weeks of time restricted feeding.

CONCLUSIONS

Time restricted feeding did not significantly alter the diversity or overall composition of the gut microbiome.

Blood Lactate Concentration Is Not Related to the Increase in Cardiorespiratory Fitness Induced by High Intensity Interval Training

Background: There is individual responsiveness to exercise training as not all individuals experience increases in maximal oxygen uptake (VO₂max), which does not benefit health status considering the association between VO₂max and mortality. Approximately 50% of the training response is genetic, with the other 50% accounted for by variations in dietary intake, sleep, recovery, and the metabolic stress of training. This study examined if the blood lactate (BLa) response to high intensity interval training (HIIT) as well as habitual dietary intake and sleep duration are associated with the resultant change in VO₂max (ΔVO₂max). Methods: Fourteen individuals (age and VO₂max = 27 ± 8 years and 38 ± 4 mL/kg/min, respectively) performed nine sessions of HIIT at 130% ventilatory threshold. BLa was measured during the first and last session of training. In addition, sleep duration and energy intake were assessed. Results: Data showed that VO₂max increased with HIIT (p = 0.007). No associations occurred between ΔVO₂max and BLa (r = 0.44, p = 0.10), energy intake (r = 0.38, p = 0.18), or sleep duration (r = 0.14, p = 0.62). However, there was a significant association between training heart rate (HR) and ΔVO₂max (r = 0.62, p = 0.02). Conclusions: When HIIT is prescribed according to a metabolic threshold, energy intake, sleep status, and BLa do not predict ΔVO₂max, yet the HR response to training is associated with the ΔVO₂max.

Validity of Dietary Assessment Methods When Compared to the Method of Doubly Labeled Water: A Systematic Review in Adults

Accuracy in quantifying energy intake (EI) using common dietary assessment methods is crucial for interpreting the relationship between diet and chronic disease. The aim of this systematic review was to evaluate the validity of dietary assessment methods used to estimate the EI of adults in comparison to total energy expenditure (TEE) measured by doubly labeled water (DLW). Articles in English across nine electronic databases, published between 1973 and February 2019 were retrieved. Studies were included if participants were adults (≥18 years) and used the DLW technique to measure TEE compared to self-reported EI. A total of 59 studies were included, with a total of 6,298 free living adults and a mean of 107 participants per study. The majority of studies including 16 studies that included a technology based method reported significant (P < 0.05) under-reporting of EI when compared to TEE, with few over-reporting EI. Misreporting was more frequent among females compared to males within recall based dietary assessment methods. The degree of under-reporting was highly variable within studies using the same method, with 24 h recalls having less variation and degree of under-reporting compared to other methods.

Comparison of self-reported dietary intakes from the Automated Self-Administered 24-h recall, 4-d food records, and food-frequency questionnaires against recovery biomarkers

Background

A limited number of studies have evaluated self-reported dietary intakes against objective recovery biomarkers.

Objective

The aim was to compare dietary intakes of multiple Automated Self-Administered 24-h recalls (ASA24s), 4-d food records (4DFRs), and food-frequency questionnaires (FFQs) against recovery biomarkers and to estimate the prevalence of under- and overreporting.

Design

Over 12 mo, 530 men and 545 women, aged 50-74 y, were asked to complete 6 ASA24s (2011 version), 2 unweighed 4DFRs, 2 FFQs, two 24-h urine collections (biomarkers for protein, potassium, and sodium intakes), and 1 administration of doubly labeled water (biomarker for energy intake). Absolute and density-based energy-adjusted nutrient intakes were calculated. The prevalence of under- and overreporting of self-report against biomarkers was estimated.

Results

Ninety-two percent of men and 87% of women completed ≥3 ASA24s (mean ASA24s completed: 5.4 and 5.1 for men and women, respectively). Absolute intakes of energy, protein, potassium, and sodium assessed by all self-reported instruments were systematically lower than those from recovery biomarkers, with underreporting greater for energy than for other nutrients. On average, compared with the energy biomarker, intake was underestimated by 15-17% on ASA24s, 18-21% on 4DFRs, and 29-34% on FFQs. Underreporting was more prevalent on FFQs than on ASA24s and 4DFRs and among obese individuals. Mean protein and sodium densities on ASA24s, 4DFRs, and FFQs were similar to biomarker values, but potassium density on FFQs was 26-40% higher, leading to a substantial increase in the prevalence of overreporting compared with absolute potassium intake.

Conclusions

Although misreporting is present in all self-report dietary assessment tools, multiple ASA24s and a 4DFR provided the best estimates of absolute dietary intakes for these few nutrients and outperformed FFQs. Energy adjustment improved estimates from FFQs for protein and sodium but not for potassium. The ASA24, which now can be used to collect both recalls and records, is a feasible means to collect dietary data for nutrition research.

Reported Energy Intake Accuracy Compared to Doubly Labeled Water and Usability of the Mobile Food Record among Community Dwelling Adults

The mobile Food Record (mFR) is an image-based dietary assessment method for mobile devices. The study primary aim was to test the accuracy of the mFR by comparing reported energy intake (rEI) to total energy expenditure (TEE) using the doubly labeled water (DLW) method. Usability of the mFR was assessed by questionnaires before and after the study. Participants were 45 community dwelling men and women, 21-65 years. They were provided pack-out meals and snacks and encouraged to supplement with usual foods and beverages not provided. After being dosed with DLW, participants were instructed to record all eating occasions over a 7.5 days period using the mFR. Three trained analysts estimated rEI from the images sent to a secure server. rEI and TEE correlated significantly (Spearman correlation coefficient of 0.58, p < 0.0001). The mean percentage of underreporting below the lower 95% confidence interval of the ratio of rEI to TEE was 12% for men (standard deviation (SD) ± 11%) and 10% for women (SD ± 10%). The results demonstrate the accuracy of the mFR is comparable to traditional dietary records and other image-based methods. No systematic biases could be found. The mFR was received well by the participants and usability was rated as easy.

The Double Layer Methodology and the Validation of Eigenbehavior Techniques Applied to Lifestyle Modeling

A novel methodology, the double layer methodology (DLM), for modeling an individual’s lifestyle and its relationships with health indicators is presented. The DLM is applied to model behavioral routines emerging from self-reports of daily diet and activities, annotated by 21 healthy subjects over 2 weeks. Unsupervised clustering on the first layer of the DLM separated our population into two groups. Using eigendecomposition techniques on the second layer of the DLM, we could find activity and diet routines, predict behaviors in a portion of the day (with an accuracy of 88% for diet and 66% for activity), determine between day and between individual similarities, and detect individual’s belonging to a group based on behavior (with an accuracy up to 64%). We found that clustering based on health indicators was mapped back into activity behaviors, but not into diet behaviors. In addition, we showed the limitations of eigendecomposition for lifestyle applications, in particular when applied to noisy and sparse behavioral data such as dietary information. Finally, we proposed the use of the DLM for supporting adaptive and personalized recommender systems for stimulating behavior change.

Comparison of a web-based food record tool and a food-frequency questionnaire and objective validation using the doubly labelled water technique in a Swedish middle-aged population

Two web-based dietary assessment tools have been developed for use in large-scale studies: the Riksmaten method (4-d food record) and MiniMeal-Q (food-frequency method). The aim of the present study was to examine the ability of these methods to capture energy intake against objectively measured total energy expenditure (TEE) with the doubly labelled water technique (TEEDLW), and to compare reported energy and macronutrient intake. This study was conducted within the pilot study of the Swedish CArdioPulmonary bioImage Study (SCAPIS), which included 1111 randomly selected men and women aged 50-64 years from the Gothenburg general population. Of these, 200 were enrolled in the SCAPIS diet substudy. TEEDLW was measured in a subsample (n 40). Compared with TEEDLW, both methods underestimated energy intake: -2·5 (sd  2·9) MJ with the Riksmaten method; -2·3 (sd 3·6) MJ with MiniMeal-Q. Mean reporting accuracy was 80 and 82 %, respectively. The correlation between reported energy intake and TEEDLW was r 0·4 for the Riksmaten method (P < 0·05) and r 0·28 (non-significant) for MiniMeal-Q. Women reported similar average intake of energy and macronutrients in both methods whereas men reported higher intakes with the Riksmaten method. Energy-adjusted correlations ranged from 0·14 (polyunsaturated fat) to 0·77 (alcohol). Bland-Altman plots showed acceptable agreement for energy and energy-adjusted protein and carbohydrate intake, whereas the agreement for fat intake was poorer. According to energy intake data, both methods displayed similar precision on energy intake reporting. However, MiniMeal-Q was less successful in ranking individuals than the Riksmaten method. The development of methods to achieve limited under-reporting is a major challenge for future research.

Energy Intake in Socially Vulnerable Women Living in Brazil: Assessment of the Accuracy of Two Methods of Dietary Intake Recording Using Doubly Labeled Water

BACKGROUND

Diet is related to the prevention of chronic diseases, but assessing dietary intake is a complex task, especially in socially vulnerable populations.

OBJECTIVES

To assess the accuracy of the 24-hour food recall (24HFR) and the food frequency questionnaire (FFQ) methods in socially vulnerable women in Brazil and compare these methods against doubly labeled water (DLW).

DESIGN

Cross-sectional study. Energy intake (EI) was measured using 3 24HFRs and 1 FFQ. Total energy expenditure (TEE) was measured using DLW. Cutoff points were calculated to assess underreporting and overreporting using both the difference and the ratio between the EI and TEE.

PARTICIPANTS/SETTING

Sixty-seven socially vulnerable, nondieting adult women with stable body weight and mothers of malnourished children.

MAIN OUTCOME MEASURES

EI, in kilocalories, derived from 24HFR and FFQ.

STATISTICAL ANALYSES

Repeated measures analysis of variance was used to compare EI and TEE and Bland-Altman graphs were plotted to assess the agreement between these variables. Spearman correlation coefficient between the ratio of EI to TEE and socioeconomic or anthropometric variables was calculated.

RESULTS

Mean TEE was 2,186 kcal (95% CI 2,063 to 2,309 kcal). EI obtained through 24HFR (mean=1,848.6 kcal [95% CI 1,737.5 to 1,959.7 kcal]) was significantly lower than TEE (P=0.01), and significantly lower than the EI obtained through FFQ (mean=2,084.5 [95% CI 1,929.0 to 2,240.0 kcal]; P<0.01). There were no statistically significant differences between the EI values of FFQ and TEE (P=0.89). The distribution of underreporters, nonunderreporters, and overreporters were more homogenous in the FFQ method. There was a positive correlation between body fat percentage and underreporting in the FFQ method (r=0.245; P=0.046).

CONCLUSIONS

The methods of assessing dietary intake in our study showed poor agreement with TEE obtained by DLW. These may, therefore, not be the most suitable methods for assessing EI in this population.

Comparison of methods to account for implausible reporting of energy intake in epidemiologic studies

In a recent article in the American Journal of Epidemiology by Mendez et al. (Am J Epidemiol. 2011;173(4):448-458), the use of alternative approaches to the exclusion of implausible energy intakes led to significantly different cross-sectional associations between diet and body mass index (BMI), whereas the use of a simpler recommended criteria (<500 and >3,500 kcal/day) yielded no meaningful change. However, these findings might have been due to exclusions made based on weight, a primary determinant of BMI. Using data from 52,110 women in the Nurses' Health Study (1990), we reproduced the cross-sectional findings of Mendez et al. and compared the results from the recommended method with those from 2 weight-dependent alternative methods (the Goldberg method and predicted total energy expenditure method). The same 3 exclusion criteria were then used to examine dietary variables prospectively in relation to change in BMI, which is not a direct function of attained weight. We found similar associations using the 3 methods. In a separate cross-sectional analysis using biomarkers of dietary factors, we found similar correlations for intakes of fatty acids (n = 439) and carotenoids and retinol (n = 1,293) using the 3 methods for exclusions. These results do not support the general conclusion that use of exclusion criteria based on the alternative methods might confer an advantage over the recommended exclusion method.

Misreporting of dietary intake affects estimated nutrient intakes in low-income Spanish-speaking women

Misreporting of dietary intake affects the validity of data collected and conclusions drawn in studies exploring diet and health outcomes. One consequence of misreporting is biological implausibility. Little is known regarding how accounting for biological implausibility of reported intake affects nutrient intake estimates in Hispanics, a rapidly growing demographic in the United States. Our study explores the effect of accounting for plausibility on nutrient intake estimates in a sample of Mexican-American women in northern California in 2008. Nutrient intakes are compared with Dietary Reference Intake recommendations, and intakes of Mexican-American women in a national survey are presented as a reference. Eighty-two women provided three 24-hour recalls. Reported energy intakes were classified as biologically plausible or implausible using the reported energy intakes to total energy expenditure cutoff of <0.76 or >1.24, with low-active physical activity levels used to estimate total energy expenditure. Differences in the means of nutrient intakes between implausible (n=36) and plausible (n=46) reporters of energy intake were examined by bivariate linear regression. Estimated energy, protein, cholesterol, dietary fiber, and vitamin E intakes were significantly higher in plausible reporters than implausible. There was a significant difference between the proportions of plausible vs implausible reporters meeting recommendations for several nutrients, with a larger proportion of plausible reporters meeting recommendations. Further research related to misreporting in Hispanic populations is warranted to explore the causes and effects of misreporting in studies measuring dietary intake, as well as actions to be taken to prevent or account for this issue.

Compliance to step count and vegetable serve recommendations mediates weight gain prevention in mid-age, premenopausal women. Findings of the 40-Something RCT

The 40-Something RCT aimed to determine if a 12-month health professional-led intervention could modify diet and physical activity behaviour for obesity prevention, in 44-50 year old, non-obese (BMI = 18.5-29.9 kg/m(2)) premenopausal women. Women were monitored for an additional 12 months to determine if effects could be maintained. This paper aimed to explore dietary and physical activity behavioural mediators hypothesised to be causally associated with weight change. Fifty-four women were randomised to a Motivational Interviewing Intervention (MI) (n = 28; five health professional consultations) or a Self-Directed Intervention (n = 26; written advice). Compliance to 10 study recommendations was measured at three months by a four-day weighed food and physical activity record including pedometer-measured step counts, self-reported exercise minutes and sitting time. The 10 compliance scores were independently assessed in mediation models for 12- and 24-month weight change. The MI effect on step count was an increase of 0.99 points on the 10-point compliance scale (p ≤ 0.01). This MI effect on step count significantly mediated the 12 and 24 month effect on weight (12 months AB = -0.74, 95%CI = -1.95, -0.14; 24 months AB = -1.06, 95% CI = -2.56, -0.36), accounting for 37.23% and 53.79% of the effect, respectively. The MI effect on vegetable serves was an increase of 1.50 points on the compliance scale (p = 0.02). The MI effect on vegetable compliance significantly mediated the effect on weight at 24 months (AB = -0.54, 95% CI = -1.50, -0.04), accounting for 24.92% of the effect. The remaining eight dietary and physical activity compliance scores did not significantly mediate weight loss. Encouraging women to take 10,000 steps and eat five vegetable serves per day may be a promising strategy to achieve long-term weight control at mid-life.

Effect of high dietary restraint on energy availability and menstrual status

INTRODUCTION

Dietary restraint (DR) is a key eating behavior associated with menstrual disturbances (MD) in exercising women. However, the association between DR and energy availability (EA) has not been examined.

PURPOSES

The objective of this study is 1) to compare EA in women when categorized by DR score, to include an evaluation of the frequency of women with low EA, and 2) to compare the distribution of subclinical and clinical MD between DR groups.

METHODS

Exercising women (23 ± 4 yr; body mass index, 21.1 ± 1.9 kg·m; and exercise volume, 333 ± 198 min·wk) were retrospectively categorized by DR score into two groups: 1) women with high DR (n = 30) and 2) women with normal DR (n = 56). DR scores were obtained from the Three-Factor Eating Questionnaire. High DR score was defined as ≥13. Body composition was measured using dual-energy x-ray absorptiometry. EA was defined as energy intake - exercise energy expenditure per kilogram lean body mass (LBM). Low EA was defined as <30 kcal·kg LBM. Menstrual status was determined using daily urinary samples assayed for reproductive hormones.

RESULTS

EA was lower in the high DR versus the normal DR group (35.0 ± 12.9 vs 42.0 ± 12.9 kcal·kg LBM, P = 0.018). There was no difference (P = 0.866) in frequency of low EA between DR groups. There was a greater frequency of MD (amenorrhea, oligomenorrhea, anovulation, or luteal phase defect) in the high DR group (21/28, 75.0%) versus the normal DR group (24/47, 51.1%) (χ = 4.2, P = 0.041).

CONCLUSION

Our findings demonstrate that exercising women with high DR exhibited lower EA and a greater frequency of MD (subclinical and clinical) compared with women with normal DR. However, high DR was not associated with low EA in exercising women.

Dietary sugar and body weight: have we reached a crisis in the epidemic of obesity and diabetes?: we have, but the pox on sugar is overwrought and overworked

In the preceding point narrative, Drs. Bray and Popkin provide their opinion and review data that suggest to them that we need to reconsider the consumption of dietary sugar based on the growing concern of obesity and type 2 diabetes. In the counterpoint narrative below, we argue that there is no clear or convincing evidence that any dietary or added sugar has a unique or detrimental impact relative to any other source of calories on the development of obesity or diabetes. Sugar is purely a highly palatable source of energy; because it has no other property that appears to contribute to our nutritional well-being, it is not an essential food for most of us. For those who wish to reduce energy consumption, ingesting less sugar is a good place to start. However, doing so does not automatically portend any clinical benefit.

Health message framing effects on attitudes, intentions, and behavior: a meta-analytic review

BACKGROUND

Message framing has been an important focus in health communication research, yet prior meta-analyses found limited support for using framing to increase persuasiveness of health messages.

PURPOSE

This meta-analysis distinguished the outcomes used to assess the persuasive impact of framed messages (attitudes, intentions, or behavior).

METHODS

One hundred eighty-nine effect sizes were identified from 94 peer-reviewed, published studies which compared the persuasive impact of gain- and loss-framed messages.

RESULTS

Gain-framed messages were more likely than loss-framed messages to encourage prevention behaviors (r = 0.083, p = 0.002), particularly for skin cancer prevention, smoking cessation, and physical activity. No effect of framing was found when persuasion was assessed by attitudes/intentions or among studies encouraging detection.

CONCLUSIONS

Gain-framed messages appear to be more effective than loss-framed messages in promoting prevention behaviors. Research should examine the contexts in which loss-framed messages are most effective, and the processes that mediate the effects of framing on behavior.

Two new meal- and web-based interactive food frequency questionnaires: validation of energy and macronutrient intake

BACKGROUND

Meal-Q and its shorter version, MiniMeal-Q, are 2 new Web-based food frequency questionnaires. Their meal-based and interactive format was designed to promote ease of use and to minimize answering time, desirable improvements in large epidemiological studies.

OBJECTIVE

We evaluated the validity of energy and macronutrient intake assessed with Meal-Q and MiniMeal-Q as well as the reproducibility of Meal-Q.

METHODS

Healthy volunteers aged 20-63 years recruited from Stockholm County filled out the 174-item Meal-Q. The questionnaire was compared to 7-day weighed food records (WFR; n=163), for energy and macronutrient intake, and to doubly labeled water (DLW; n=39), for total energy expenditure. In addition, the 126-item MiniMeal-Q was evaluated in a simulated validation using truncated Meal-Q data. We also assessed the answering time and ease of use of both questionnaires.

RESULTS

Bland-Altman plots showed a varying bias within the intake range for all validity comparisons. Cross-classification of quartiles placed 70%-86% in the same/adjacent quartile with WFR and 77% with DLW. Deattenuated and energy-adjusted Pearson correlation coefficients with the WFR ranged from r=0.33-0.74 for macronutrients and was r=0.18 for energy. Correlations with DLW were r=0.42 for Meal-Q and r=0.38 for MiniMeal-Q. Intraclass correlations for Meal-Q ranged from r=0.57-0.90. Median answering time was 17 minutes for Meal-Q and 7 minutes for MiniMeal-Q, and participants rated both questionnaires as easy to use.

CONCLUSIONS

Meal-Q and MiniMeal-Q are easy to use and have short answering times. The ranking agreement is good for most of the nutrients for both questionnaires and Meal-Q shows fair reproducibility.

The relevance of dietary sodium in hemodialysis

Since the earliest days of hemodialysis, dietary sodium restriction has been recommended as a therapeutic means to mitigate problems of extracellular volume overload, hypertension and inter-dialytic weight gain. Recently, there has been a proliferation of human subjects' research examining the potential effects of dietary sodium curtailment. Herein we examine the available evidence with respect to the effects of dietary sodium restriction on clinically relevant endpoints among hemodialysis patients.

Assessing dietary intake: Who, what and why of under-reporting

Under-reporting of food intake is one of the fundamental obstacles preventing the collection of accurate habitual dietary intake data. The prevalence of under-reporting in large nutritional surveys ranges from 18 to 54% of the whole sample, but can be as high as 70% in particular subgroups. This wide variation between studies is partly due to different criteria used to identify under-reporters and also to non-uniformity of under-reporting across populations. The most consistent differences found are between men and women and between groups differing in body mass index. Women are more likely to under-report than men, and under-reporting is more common among overweight and obese individuals. Other associated characteristics, for which there is less consistent evidence, include age, smoking habits, level of education, social class, physical activity and dietary restraint. Determining whether under-reporting is specific to macronutrients or food is problematic, as most methods identify only low energy intakes. Studies that have attempted to measure under-reporting specific to macronutrients express nutrients as percentage of energy and have tended to find carbohydrate under-reported and protein over-reported. However, care must be taken when interpreting these results, especially when data are expressed as percentages. A logical conclusion is that food items with a negative health image (e.g. cakes, sweets, confectionery) are more likely to be under-reported, whereas those with a positive health image are more likely to be over-reported (e.g. fruits and vegetables). This also suggests that dietary fat is likely to be under-reported. However, it is necessary to distinguish between under-reporting and genuine under-eating for the duration of data collection. The key to understanding this problem, but one that has been widely neglected, concerns the processes that cause people to under-report their food intakes. The little work that has been done has simply confirmed the complexity of this issue. The importance of obtaining accurate estimates of habitual dietary intakes so as to assess health correlates of food consumption can be contrasted with the poor quality of data collected. This phenomenon should be considered a priority research area. Moreover, misreporting is not simply a nutritionist's problem, but requires a multidisciplinary approach (including psychology, sociology and physiology) to advance the understanding of under-reporting in dietary intake studies.

The association of macro- and micronutrient intake with growth hormone secretion

CONTEXT

Growth hormone (GH) is known to be nutritionally regulated, but the effect of dietary composition on detailed GH secretion parameters has not previously been comprehensively evaluated.

OBJECTIVE

The objective of the study was to determine whether specific macro- and micronutrients are associated with discrete parameters of GH secretion among subjects with wide ranges of body mass index.

DESIGN

Detailed macro- and micronutrient intake was assessed by 4-day food records while GH secretion was assessed by standard stimulation testing in 108 men and women in one study (Study 1), and by overnight frequent blood sampling in 12 men in another study (Study 2).

RESULTS

Peak stimulated GH was positively associated with vitamin C (r=+0.29; P=0.003), dietary fiber (r=+0.27; P=0.004), arachidic acid (r=+0.25; P=0.008), and behenic acid (r=+0.30; P=0.002) intake in univariate analysis. Controlling for age, gender, race/ethnicity, visceral fat, HOMA-IR, total caloric intake and these four dietary factors in step-wise multivariate modeling, peak GH remained significantly associated with vitamin C and visceral fat (both P<0.05). In addition, vitamin C intake was associated with various parameters of endogenous GH secretion including basal GH secretion (r=+0.95; P<0.0001), GH half-life (r=+.75; P=0.005), total GH production (r=+0.76; P=0.004), GH area-under-the-curve (r=+0.89; P=0.0001), mean log(10) GH pulse area (r=+0.67; P=0.02), and overnight maximum (r=+0.62; P=0.03), nadir (r=+0.97; P<0.0001), and mean GH secretion (r=+0.89; P=0.0001).

CONCLUSIONS

These results suggest that certain micronutrients such as vitamin C intake are strongly and uniquely associated with stimulated and endogenous spontaneous GH secretion.

Approaches for quantifying energy intake and %calorie restriction during calorie restriction interventions in humans: the multicenter CALERIE study

Calorie restriction (CR) is a component of most weight loss interventions and a potential strategy to slow aging. Accurate determination of energy intake and %CR is critical when interpreting the results of CR interventions; this is most accurately achieved using the doubly labeled water method to quantify total energy expenditure (TEE). However, the costs and analytical requirements of this method preclude its repeated use in many clinical trials. Our aims were to determine 1) the optimal TEE assessment time points for quantifying average energy intake and %CR during long-term CR interventions and 2) the optimal approach for quantifying short-term changes in body energy stores to determine energy intake and %CR during 2-wk DLW periods. Adults randomized to a CR intervention in the multicenter CALERIE study underwent measurements of TEE by doubly labeled water and body composition at baseline and months 1, 3, and 6. Average %CR achieved during the intervention was 24.9 ± 8.7%, which was computed using an approach that included four TEE assessment time points (i.e., TEE(baseline, months 1, 3, and 6)) plus the 6-mo change in body composition. Approaches that included fewer TEE assessments yielded %CR values of 23.4 ± 9.0 (TEE(baseline,) months 3 and 6), 25.0 ± 8.7 (TEE(baseline,) months 1 and 6), and 20.9 ± 7.1% (TEE(baseline, month 6)); the latter approach differed significantly from approach 1 (P < 0.001). TEE declined 9.6 ± 9.9% within 2-4 wk of CR beginning and then stabilized. Regression of daily home weights provided the most reliable estimate of short-term change in energy stores. In summary, optimal quantification of energy intake and %CR during weight loss necessitates a TEE measurement within the first month of CR to capture the rapid reduction in TEE.

Dealing with dietary measurement error in nutritional cohort studies

Dietary measurement error creates serious challenges to reliably discovering new diet-disease associations in nutritional cohort studies. Such error causes substantial underestimation of relative risks and reduction of statistical power for detecting associations. On the basis of data from the Observing Protein and Energy Nutrition Study, we recommend the following approaches to deal with these problems. Regarding data analysis of cohort studies using food-frequency questionnaires, we recommend 1) using energy adjustment for relative risk estimation; 2) reporting estimates adjusted for measurement error along with the usual relative risk estimates, whenever possible (this requires data from a relevant, preferably internal, validation study in which participants report intakes using both the main instrument and a more detailed reference instrument such as a 24-hour recall or multiple-day food record); 3) performing statistical adjustment of relative risks, based on such validation data, if they exist, using univariate (only for energy-adjusted intakes such as densities or residuals) or multivariate regression calibration. We note that whereas unadjusted relative risk estimates are biased toward the null value, statistical significance tests of unadjusted relative risk estimates are approximately valid. Regarding study design, we recommend increasing the sample size to remedy loss of power; however, it is important to understand that this will often be an incomplete solution because the attenuated signal may be too small to distinguish from unmeasured confounding in the model relating disease to reported intake. Future work should be devoted to alleviating the problem of signal attenuation, possibly through the use of improved self-report instruments or by combining dietary biomarkers with self-report instruments.

Exercising women with menstrual disturbances consume low energy dense foods and beverages

Women with exercise-associated menstrual cycle disturbances (EAMD) restrict energy intake. Reducing energy density (ED; kcals·g–1of food or beverage) may be a strategy employed by EAMD women to maintain lower energy intake. The purpose of this study was 3-fold: to determine whether EAMD women consume low ED diets; to identify food groups associated with low ED; and to determine concentrations of total peptide YY (PYY), a satiety factor. Twenty-five active females were divided into 2 groups, according to menstrual status: EAMD (n = 12) and ovulatory controls (OV) (n = 13). Two 3-day diet records were analyzed for ED and other parameters. Body composition, fitness, resting metabolic rate, and PYY were measured. Groups did not differ in age, age of menarche, body mass index, maximal aerobic capacity, body fat (%), or amount of exercise per week. For fat mass (12.4 ± 1.7 vs. 14.9 ± 3.5 kg; p = 0.046), energy availability (28.8 ± 11.5 vs. 42.1 ± 9.2 kcal·kg–1FFM; p = 0.006), and energy intake (29.8 ± 9.2 vs. 36.3 ± 10.6 kcals·kg–1BW; p = 0.023), EAMD was lower than OV. ED was lower in EAMD than in OV (0.77 ± 0.06 vs. 1.06 ± 0.09 kcal·g–1; p = 0.018) when all beverages were included, but not when noncaloric beverages were excluded. Vegetable (p = 0.047) and condiment (p = 0.014) consumption and fasting PYY (pg·mL–1) (p = 0.006) were higher in EAMD. EAMD ate a lower ED diet through increased vegetable, condiment, and noncaloric beverage consumption, and exhibited higher PYY concentrations. These behaviors may represent a successful strategy to restrict calories and maximize satiety.

Energy expenditure in adults living in developing compared with industrialized countries: a meta-analysis of doubly labeled water studies

BACKGROUND

There is an assumption that people in developing countries have a higher total energy expenditure (TEE) and physical activity level (PAL) than do people in developed nations, but few objective data for this assertion exist.

OBJECTIVE

We conducted a meta-analysis of TEE and PAL by using data from countries that have a low or middle human development index (HDI) compared with those with a high HDI to better understand how energy-expenditure variables are associated with development status and population differences in body size.

DESIGN

We performed a literature search for studies in which energy expenditure was measured by using doubly labeled water. Mean data on age, weight, body mass index (BMI; in kg/m(2)), TEE, and PAL were extracted, and HDI status was assessed. Pooled estimates of the mean effect by sex were obtained, and the extent to which age, weight, HDI status, and year of publication explained heterogeneity was assessed.

RESULTS

A total of 98 studies (14 studies from low- or middle-HDI countries) that represented 183 cohorts and 4972 individuals were included. Mean (±SE) BMI was lower in countries with a low or middle HDI than in those with a high HDI for both men and women (22.7 ± 1.0 compared with 26.0 ± 0.7, respectively, in men and 24.3 ± 0.7 compared with 26.6 ± 0.4, respectively, in women). In meta-regression models, there was an inverse association of age (P < 0.001) and a positive association of weight (P < 0.001) with TEE for both sexes; there was an association of age only in men with PAL (P < 0.001). There was no association of HDI status with either TEE or PAL.

CONCLUSION

TEE adjusted for weight and age or PAL did not differ significantly between developing and industrialized countries, which calls into question the role of energy expenditure in the cause of obesity at the population level.

Energy balance in advanced chronic kidney disease and end-stage renal disease

Energy intake, resting energy expenditure, and energy expended for physical activity (EEPA) are components of energy balance that may be disrupted by a number of disorders and clinical conditions commonly present in advanced chronic kidney disease (CKD) and end-stage renal disease (ESRD). Energy intake of patients with CKD has been consistently lower than the recommended intake in multiple reports. On the other hand, while reduced energy intake due to anorexia may be applicable for ESRD patients with overt protein-energy wasting, it is potentially unrealistic for overweight or obese subjects who are able to maintain their body weight. Studies on resting energy expenditure have provided mixed results, most likely as a consequence of differences in the population characteristics, clinical conditions, and stage of the disease. Finally, although there is lack of specific studies on EEPA, there is evidence that ESRD patients, particularly those undergoing hemodialysis are in general less active than sedentary healthy individuals. These observations may raise questions regarding the accuracy of dietary reports and the uncertainties related to the energy requirements, optimal dietary energy intake, and recommendations for physical activity in these patients.

Estimated nutrient intakes from food generally do not meet dietary reference intakes among adult members of Pacific Northwest tribal nations

Diet is influential in the etiology of chronic diseases in many populations including Native Americans. The objective of this report is to present the first comprehensive dietary survey, to our knowledge, of a representative sample of nonpregnant adults from Pacific Northwest tribal nations participating in the Communities Advancing the Studies of Tribal Nations Across the Lifespan (CoASTAL) cohort. Only participants who completed 1-4 d of dietary records and had weights and heights measured in the laboratory were eligible for this analysis (n = 418). Mean nutrient intakes were stratified by gender for the total sample, those with plausibly reported energy intakes (rEI), and those with implausibly rEI. Estimates of nutrient intakes were compared with Dietary Reference Intakes (DRI). Nutrient estimates from NHANES 2001-2002 were used as a reference. Among both men and women, total fat contributed 34-37% of energy intake and saturated fat contributed 11-12% of energy intake. Daily cholesterol intakes ranged from 262 to 442 mg. A majority of men and women were not meeting recommendations for vitamins A, C, and E, magnesium, and sodium. For a majority of the nutrients examined, plausibility resulted in higher mean estimates. The CoASTAL cohort nutrient profile is similar to NHANES 2001-2002, with a majority of DRI recommendations not being met. Adequate dietary intake information may be more important for this population, because Native Americans experience a disproportionate burden for diseases.

Evaluation of dietary assessment tools used to assess the diet of adults participating in the Communities Advancing the Studies of Tribal Nations Across the Lifespan cohort

BACKGROUND

Accurate assessment of dietary intake is essential for researchers and public health practitioners to make advancements in public health. This is especially important in Native Americans who display disease prevalence rates that are dramatically higher than the general US population.

OBJECTIVE

To evaluate three dietary assessment tools: dietary records, a food frequency questionnaire (FFQ), and a shellfish assessment survey among Native American adults from the Communities Advancing the Studies of Tribal Nations Across the Lifespan (CoASTAL) cohort.

DESIGN

The CoASTAL cohort was composed of randomly selected individuals from three tribal registries of Pacific Northwest Tribal Nations. This cross-sectional study used data from the baseline of CoASTAL and was restricted to the non-pregnant adults (aged 18 years or older) who completed the shellfish assessment survey (n=500), an FFQ (n=518), dietary records (n=444), weight measures (n=493), and height measures (n=496). Paired t tests, Pearson correlation coefficients, and percent agreement were used to evaluate the dietary records and the FFQ with and without accounting for plausibility of reported energy intake (rEI). Sensitivity and specificity as well as Spearman correlation coefficients were used to evaluate the shellfish assessment survey and the FFQ compared to dietary records.

RESULTS

Statistically significant correlations between the FFQ and dietary records for selected nutrients were not the same by sex. Accounting for plausibility of rEI for the dietary records and the FFQ improved the strength of the correlations for percent energy from protein, energy from carbohydrate, and calcium for both men and women. In addition, the association between rEI (dietary records and FFQ) and weight became significant when the sample was limited to plausible rEI. The shellfish assessment survey was found to similarly assess shellfish consumption in comparison to the FFQ.

CONCLUSIONS

These results support the benefit of multiple measures of diet, including regional and culturally specific surveys, especially among Native Americans. Accounting for plausibility of rEI may ensure more accurate estimations of dietary intakes.

One-year weight maintenance after significant weight loss in healthy overweight and obese subjects: does diet composition matter?

BACKGROUND

For many people, maintenance of weight loss is elusive. Whereas high-protein (HP) diets have been found to be superior to high-carbohydrate (HC) diets for weight loss in the short term, their benefits long term are unclear, particularly for weight maintenance. Furthermore, the literature lacks consensus on the long-term effects of an HP diet on cardiovascular disease risk factors.

OBJECTIVE

The objective was to investigate whether macronutrient dietary composition plays a role in weight maintenance and in improvement of cardiovascular disease risk factors.

DESIGN

The study comprised 2 phases. Phase 1 featured a very-low-energy diet for 3 mo. In phase 2, the subjects were randomly assigned to an HP or an HC diet for 12 mo. The diets were isocaloric, tightly controlled, and individually prescribed for weight maintenance. The subjects were overweight or obese but otherwise healthy men and women.

RESULTS

The subjects lost an average of 16.5 kg during phase 1 and maintained a mean (+/-SEM) weight loss of 14.5 +/- 1.2 kg (P < 0.001) during phase 2; no significant differences between groups were observed. By the end of the study, reductions in systolic blood pressure were 14.3 +/- 2.4 mm Hg for the HP group and 7.7 +/- 2.2 mm Hg for the HC group (P < 0.045). Forty-seven percent of the 180 subjects who began the study completed both phases.

CONCLUSIONS

The results indicate that the protein or carbohydrate content of the diet has no effect on successful weight-loss maintenance. A general linear model analysis indicated that dietary treatment (HP or HC) was a significant factor in systolic blood pressure change and in favor of the HP diet. This trial was registered at www.clinicaltrials.gov as NCT 00625236.

Misreporting of energy and micronutrient intake estimated by food records and 24 hour recalls, control and adjustment methods in practice

In order to assess nutritional adequacy, valid estimates of nutrient intake are required. One of the main errors in dietary assessment is misreporting. The objective was to review the extent, nature and determinants of misreporting in dietary assessment, how this affects reported intakes of micronutrients and how this is identified and measured, and to identify the best ways of dealing with misreporting when interpreting results. A systematic literature search was conducted for studies of misreporting of dietary intake in adults by 24 hour recalls or by estimated or weighed food records, published up to March 2008. Thirty-seven relevant studies were identified. Possible causes of misreporting were identified. Methods most used to identify misreporting were the Goldberg cut-off (46 % studies) and the doubly labelled water technique (24 % studies). The magnitude of misreporting of energy intake was similar in all three dietary assessment methods. The percentage of under-reporters was about 30 % and energy intake was underestimated by approximately 15 %. Seven papers presented usable data for micronutrient intake. Absolute intakes of Fe, Ca and vitamin C (the three micronutrients addressed in all papers) were on average 30 % lower in low-energy reporters (LER) than that in non-LER and, although results were not consistent, there was a tendency for micronutrient density to be higher in LER. Excluding underreporters or using energy adjustment methods for micronutrient intakes is discussed. Residual method of energy adjustment seems to be a good tool for practice to decrease an influence of misreporting when interpreting results of studies based on food records and 24 hour recalls.

Social desirability trait influences on self-reported dietary measures among diverse participants in a multicenter multiple risk factor trial

Data collected at 4 Behavioral Change Consortium sites were used to assess social desirability bias in self-reports derived from a dietary fat screener (PFat), a dietary fruit and vegetable screener (FVS), and a 1-item question on fruit and vegetable intake. Comparisons were made with mean intakes derived from up to 3 24-h recall interviews at baseline and follow-up (at 12 mo in 3 sites, 6 mo in the fourth). A social-desirability-related underestimate in fat intake on the PFat relative to the 24HR (percentage energy as fat) was evident in women [baseline b = -0.56 (P = 0.005); follow-up b = -0.62 (P < 0.001)]. There was an overestimate in FVS-derived fruit and vegetable consumption (servings/week) in men enrolled in any intervention at follow-up (b = 0.39, P = 0.05) vs. baseline (b = 0.04, P = 0.75). The 1-item fruit and vegetable question was associated with an overestimate at baseline in men according to SD score (b = 0.14, P = 0.02), especially men with less than college education (b = 0.23, P = 0.01). Women with less than college education expressed a similar bias at follow-up (b = 0.13, P = 0.02). Differences in the magnitude of bias according to gender, type of instrument used, and randomization condition are comparable to what has been seen for other instruments and have important implications for both measuring change in studies of diet and health outcomes and for developing methods to control for such biases.

Logistic regression with exposure biomarkers and flexible measurement error

Regression calibration, refined regression calibration, and conditional scores estimation procedures are extended to a measurement model that is motivated by nutritional and physical activity epidemiology. Biomarker data, available on a small subset of a study cohort for reasons of cost, are assumed to adhere to a classical measurement error model, while corresponding self-report nutrient consumption or activity-related energy expenditure data are available for the entire cohort. The self-report assessment measurement model includes a person-specific random effect, the mean and variance of which may depend on individual characteristics such as body mass index or ethnicity. Logistic regression is used to relate the disease odds ratio to the actual, but unmeasured, dietary or physical activity exposure. Simulation studies are presented to evaluate and contrast the three estimation procedures, and to provide insight into preferred biomarker subsample size under selected cohort study configurations.

Development and evaluation of a short instrument to estimate usual dietary intake of percentage energy from fat

OBJECTIVE

To describe the data-based development of a short dietary assessment instrument, a 16-item screener; and to evaluate the performance of the screener, comparing its performance with a complete 120-item food frequency questionnaire (FFQ) in assessing percentage energy from fat intake.

DESIGN

A subsample (n=404) of participants in the National Institutes of Health-AARP Diet and Health Study, who had completed an FFQ and two 24-hour dietary recalls, also completed the fat screener. Percentage energy from fat from the screener and from the FFQ were compared with estimated true usual intake using a measurement error model.

RESULTS

For men, the mean percentage energy from fat estimates for the different methods were: recalls, 30.1%, screener, 29.9%; FFQ, 30.4%. For women, the results were: recalls, 31.3%, screener, 28.4%, FFQ, 30.0%. Estimated correlations between true intake and screener were 0.64 and 0.58 for men and women, respectively, and between true intake and FFQ were 0.67 for men and 0.72 for women. Estimated attenuation coefficients for the screener were 1.29 (men) and 0.98 (women) and for the FFQ were 0.56 (men) and 0.57 (women).

CONCLUSIONS

The percentage energy from fat screener, when used in conjunction with external reference data, may be useful to compare mean intakes of fat for different population subgroups, and to examine relationships between fat intake and other factors.

Validation of a short food frequency questionnaire to assess folate intake

A short quantitative food frequency questionnaire (FFQ) to assess folate intake was developed and validated against a 7-d weighed food intake record (7d-WR) and biochemical indices of folate status. Thirty-six men and women completed the self-administered FFQ on two occasions a month apart, kept a 7d-WR and gave two fasting blood samples at the beginning and end of the study for measuring serum and erythrocyte folate, respectively. Mean folate intakes were similar by repeat FFQ and correlated strongly (r 0·77 and r 0·72, P<0·001, for men and women, respectively). All other comparisons were done using the results of the FFQ administered on the first occasion. Men reported similar folate intakes on the FFQ and 7d-WR, but women reported greater intakes on the FFQ compared with the 7d-WR (P<0·05). There was a statistically significant correlation (partial, controlling for gender) between folate intakes reported by FFQ and 7d-WR (r 0·53, P<0·01). Folate intakes estimated by FFQ correlated significantly with serum (r 0·47, P<0·01), but not erythrocyte folate (r 0·25, P>0·05); the strength of the association was greater in men than in women. Validity coefficients estimated using the method of triads were higher for the FFQ than for the 7d-WR when serum folate was used as the biomarker. Overall, these results suggest that this short FFQ is a useful method for assessing folate intake, particularly in men.

Improved reporting of habitual food intake after confrontation with earlier results on food reporting

The aim of the present study was to improve the reporting of food intake by confronting subjects with their way of reporting food intake, e.g. under-recording and/or undereating. To minimize portion size errors, eighteen female dietitians were recruited as subjects. Energy- and water intake were measured for 1 week with a weighed dietary record. Resting metabolic rate was measured with an open-circuit ventilated-hood indirect calorimeter, and physical activity was measured with an accelerometer for movement registration. Water loss was estimated with 2H-labelled water. Energy balance was checked for by measuring empty body-weight 1 week before the start, at the start and at the end of the recording week. In the first part of the study, the change in body weight in the non-recording week was 0·14 kg and in the recording week -0·45 kg (P 0·02), indicating 12 % undereating. Total water intake closely matched measured water loss, indicating a high recording precision. There was under-reporting of habitual food intake that could be fully explained by undereating. In the second part of the study, subjects were confronted with these results and the protocol was repeated. This time there was no significant change in body weight in the recording week, indicating no undereating. The reporting of habitual food intake had been improved. In conclusion, in the studied group of highly motivated lean women, under-reporting of habitual food intake (here due to undereating) could be eliminated by confrontation with the results of this phenomenon.

Evaluation of dietary intake data using the tolerable upper intake levels

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

Racial differences in correlates of misreporting of energy intake in adolescent females

OBJECTIVE

To determine the extent of misreporting of energy intake (EI) and its anthropometric, demographic, and psychosocial correlates in a bi-racial cohort of young women.

RESEARCH METHODS AND PROCEDURES

This was a cross-sectional study of 60 black and 60 white young women, 18 to 21 years old, enrolled in a longitudinal study. Total energy expenditure was assessed using doubly labeled water. Self-reported EI was obtained from 3-day food records. BMI was computed from height and weight. Fat mass was assessed by DXA. Multivariate analyses examined racial differences on the extent of misreporting and its effect on other potential correlates of misreporting. Race-specific step-wise linear regression analysis was performed to examine the effect of BMI, parental education, and drive for thinness on misreporting of EI.

RESULTS

More white women tended to under-report EI than black women (22% vs. 13%, p = 0.07). In black women, under-reporting was significantly (p = 0.01) associated with drive for thinness score but was only marginally (p = 0.1) associated with BMI. Each point increase in drive for thinness score was associated with under-reporting by 40 kcal/d. In white women, under-reporting was significantly (p = 0.03) associated with higher parental education by 440 kcal/d and also only marginally (p = 0.09) with BMI.

DISCUSSION

This tendency for under-reporting of EI limits the use of self-reported EI in studying energy balance in free-living subjects. Most black and almost all white women in their late teens significantly under-reported their EI, whereas under-reporting was not as evident among lean young black women.

An easy-to-use semiquantitative food record validated for energy intake by using doubly labelled water technique

BACKGROUND

Estimating dietary intake is important for both epidemiological and clinical studies, but often lacks accuracy.

OBJECTIVE

To investigate the accuracy and validity of energy intake estimated by an easy-to-use semiquantitative food record (EI(SQFR)) compared to total energy expenditure (TEE) estimated by doubly labelled water technique (EE(DLW)).

DESIGN

TEE was measured in 29 nonobese subjects using the doubly labelled water method over a period of 14 days. Within this period, subjects reported their food consumption by a newly developed semiquantitative food record for 4 consecutive days. Energy intake was calculated using the German Food Code and Nutrition Data Base BLS II.3.

RESULTS

A good correlation was observed between EI(SQFR) and EE(DLW) (r = 0.685, P < 0.001). The mean difference between EI(SQFR) and EE(DLW) was -1.7+/-2.6 MJ/day (-14+/-21%, P = 0.002). An underestimation of EI(SQFR) <10% was observed in nine subjects (31%), of 10-20% in six subjects (21%), and of >20% in nine subjects (31%). In five subjects (17%), an overestimation of EI(SQFR) was observed.

CONCLUSIONS

The easy-to-use semiquantitative food record provided good estimates of EI in free-living and nonobese adults without prior detailed verbal instructions. The presented food record has limitations regarding accuracy at the individual level.

Short-term effects of a very-low-protein diet supplemented with ketoacids in nondialyzed chronic kidney disease patients

OBJECTIVE

To evaluate the effects on the nutritional and metabolic parameters of a very-low-protein diet supplemented with ketoacids (VLPD+KA) in comparison with a conventional low-protein diet (LPD) in chronic kidney disease (CKD) patients.

DESIGN

Prospective, randomized, controlled clinical study.

SETTING

Outpatient Clinic of the Nephrology Division of Federal University of Sao Paulo, Brazil.

SUBJECTS

The study involved 24 patients with advanced CKD (creatinine clearance <25 ml/min) that were randomly assigned to either a VLPD+KA (VLPD+KA group, 12 patients) or to a conventional LPD with 0.6 g/kg/day (LPD group, 12 patients). The patients were followed for 4 months.

RESULTS

Nutritional status was adequately maintained with both diets for the studied period. Protein intake and serum urea nitrogen decreased significantly only in the VLPD+KA group (from 0.68+/-0.17 to 0.43+/-0.12 g/kg/day, P<0.05; from 61.4+/-12.8 to 43.6+/-14.9 mg/dl, P<0.001; respectively). Ionized calcium did not change in the VLPD+KA group but tended to decrease in the LPD group. Serum phosphorus tended to decrease in the VLPD+KA group probably as a result of a significant reduction in dietary phosphorus (529+/-109 to 373+/-125 mg/day, P<0.05) associated to the phosphorus-binding effect of the ketoacids. No change in these parameters was found in the LPD group. Serum parathormone increased significantly only in the LPD group (from 241+/-138 to 494+/-390 pg/ml, P<0.01). The change in PTH concentration was negatively correlated with changes in ionized calcium concentration (r=-0.75, P=0.02) and positively correlated with changes in serum phosphorus (r=0.71, P=0.03) only in the LPD group.

CONCLUSION

This study indicates that a VLPD+KA can maintain the nutritional status of the patients similarly to a conventional LPD. Besides, an improvement in calcium and phosphorus metabolism and a reduction in serum urea nitrogen were attained only with the VLPD+KA. Thus, VLPD+KA can constitute another efficient therapeutic alternative in the treatment of CKD patients.