OBJECTIVE: High water consumption has been proposed as an aid to weight control and as a means of reducing the energy density of the diet. This study examines the relationship between water consumption and other drinking and eating patterns. RESEARCH METHODS AND PROCEDURES: The National Health and Nutrition Examination Survey 1999 to 2001, with responses from 4755 individuals [>/=]18 years of age, provides the data for this cross-sectional analysis. A cluster analysis was performed using z-scores of specific food and beverage consumption to examine patterns. A multinomial logit analysis was used to examine sociodemographic characteristics of each dietary pattern and to examine the effects of water consumption on the likelihood of consuming a non-dairy caloric beverage. All results were weighted to be nationally representative and controlled for design effects. RESULTS: Within the sample, 87% consumed water, with an average daily consumption of 51.9 oz (1.53 liters) per consumer. Water consumers drank fewer soft/fruit drinks and consumed 194 fewer calories per day. Water consumers (potentially a self-selected sample) consumed more fruits, vegetables, and low- and medium-fat dairy products. Four distinct unhealthy dietary patterns were found that included little or no water consumption. Older and more educated persons used healthier food patterns. Mexican dietary patterns were much healthier than dietary patterns of blacks. DISCUSSION: Water consumption potentially is a dietary component to be promoted, but much more must be understood about its role in a healthy diet. Because high water consumption is linked with healthier eating patterns--patterns more likely to be followed by higher-educated, older adults--the target of water promotion and healthy diet options should focus on younger and less educated adults.

Mice were fed an agar-based diet without an additional source of water for 5 weeks. In comparison with a similar group of mice fed a commercial diet and water ad libitum, there were no significant changes in bodyweight.

Glucagon-like peptide (GLP)-1-(7-36) amide and its pancreatic receptors are important for control of blood glucose levels. However, rat GLP-1 receptors are also localized in the brain, in hypothalamus, and in areas without a blood-brain barrier. When rats were kept on a food restriction schedule, intracerebroventricular injection of GLP-1 just before food was offered inhibited food intake. However, peripheral GLP-1 administration by intraperitoneal injection had little effect. GLP-1 effects on water intake and output were also investigated. Intracerebroventricular GLP-1 profoundly inhibited angiotensin II-induced drinking behavior in rats, and water intake was suppressed by exogenous GLP-1 in rats habituated to a water restriction schedule. These effects were reproduced by intraperitoneal administration of GLP-1. Furthermore, intracerebroventricular GLP-1 stimulated urinary excretion of water and sodium. The centrally elicited effects were blocked by the GLP-1 antagonist exendin-(9-39) amide, whereas the N-terminally extended and inactive GLP-1-(1-36) amide had no effect on feeding and drinking. GLP-1 had no effect in behavioral assays measuring exploratory locomotor activity and conditioned taste aversion. In conclusion, GLP-1 may play a physiological role in regulation of both ingestion and the water and salt homeostasis.

More and more people in Bangladesh have recently become aware of the risk of drinking arsenic-contaminated groundwater, and have been trying to obtain drinking water from less arsenic-contaminated sources. In this study, arsenic intakes of 18 families living in one block of a rural village in an arsenic-affected district of Bangladesh were evaluated to investigate their actual arsenic intake via food, including from cooking water, and to estimate the contribution of each food category and of drinking water to the total arsenic intake. Water consumption rates were estimated by the self-reporting method. The mean drinking water intake was estimated as about 3 L/d without gender difference. Arsenic intakes from food were evaluated by the duplicate portion sampling method. The duplicated foods from each family were divided into four categories (cooked rice, solid food, cereals for breakfast, and liquid food), and the arsenic concentrations of each food category and of the drinking water were measured. The mean arsenic intake from water and food by all 18 respondents was 0.15 ± 0.11 mg/d (range, 0.043 - 0.49), that by male subjects was 0.18 ± 0.13 mg/d (n = 12) and that by female subjects was 0.096 ± 0.007 mg/d (n = 6). The average contributions to the total arsenic intake were, from drinking water, 13%; liquid food, 4.4%; cooked rice, 56%; solid food, 11%; and cereals, 16%. Arsenic intake via drinking water was not high despite the highly contaminated groundwater in the survey area because many families had changed their drinking water sources to less-contaminated ones. Instead, cooked rice contributed most to the daily arsenic intake. Use of contaminated water for cooking by several families was suspected based on comparisons of arsenic concentrations between drinking water and liquid food, and between rice before and after cooking. Detailed investigation suggested that six households used contaminated water for cooking but not drinking, leading to an increase of arsenic intake via arsenic-contaminated cooking water.

Objective: We assessed the extent of energy misreporting from the use of a self-administered 7-day diet record (7-DDR) and a widely used food frequency questionnaire (FFQ) compared to total energy expenditure from doubly labeled water (DLW) in a group of postmenopausal women. Design: At baseline, 65 healthy postmenopausal women were instructed to fill out the National Cancer Institute's (NCI) FFQ and a 7-DDR. Average total energy expenditure using the DLW method was also performed at baseline. Results: On average, the women underestimated total energy intake compared to total energy expenditure assessed from DLW by 37% on the 7-DDR and 42% on the FFQ. Conclusions: These findings suggest that the interpretation of findings from the 7-DDR- and FFQ-based energy-disease association studies in postmenopausal women needs further evaluation. Sponsorship: This research was supported (in part) by the Intramural Program of the NIH (National Cancer Institute).

Objective: To study whether eating or physical-activity (PA) habits differ between obese and non-obese monozygotic (MZ) co-twins independent of genetic effects. Methods: Rare MZ pairs discordant for obesity (n=14, body mass index difference 5.2±1.8 kg m–2) and weight-concordant control pairs (n=10, 1.0±0.7 kg m–2), identified through a population-based registry of 24–28-year-old twins (n=658 MZ pairs), completed 3-day food and PA diaries and eating behavior questionnaires. Each twin was asked to compare his/her own eating and PA patterns with the co-twin's behavior by structured questionnaires. Accuracy of energy intake was validated by doubly labeled water. Results: Non-obese co-twins consistently reported that their obese twin siblings ate more food overall, consumed less healthy foods and exercised less than the non-obese co-twins do. However, no differences in energy intake (9.6±1.0 MJ per day vs 9.8±1.1 MJ per day, respectively) in the food diaries or in the mean PA level (1.74±0.02 vs 1.79±0.04, respectively) in the PA diaries were found between obese and non-obese co-twins. A considerable underreporting of energy intake (3.2±1.1 MJ per day, P=0.036) and overreporting of PA (1.8±0.8 MJ per day, P=0.049) was observed in the obese, but not in the non-obese co-twins. Conclusions: On the basis of rare MZ twin pairs discordant for obesity, the co-twin assessments confirmed substantial differences in eating and PA behavior between obese and non-obese persons. These may be overlooked in population studies using food and PA diaries because of considerable misreporting by the obese.

Background: Measurements of dietary intake in obese and overweight populations are often inaccurate because food intakes are underestimated. Objective: The purpose of this study was to evaluate the validity of the combined use of observer-recorded weighed-food records and 24-h snack recalls in estimating energy intakes in overweight and obese individuals. Design: Subjects were 32 healthy women and 22 healthy men with mean body mass indexes (in kg/m2) of 29.5 and 30.3, respectively. Energy intake (EI) was measured over 2 wk in a university cafeteria. No restrictions were made on meal frequency or EI. To document food consumed outside the cafeteria, 24-h snack recalls were conducted before meals. Energy expenditure (EE) was measured with the doubly labeled water (DLW) method (EEDLW). Energy balance was determined by measuring body weight at the beginning and end of the 2-wk period. Results: The mean EI in the women (10.40 +/- 1.94 MJ/d) and men (14.37 +/- 3.21 MJ/d) was not significantly lower than the EEDLW in the women (10.86 +/- 1.76 MJ/d) and men (14.14 +/- 2.83 MJ/d). The mean EI represented 96.9 +/- 17.0% and 103 +/- 18.9% of the measured EE for women and men, respectively. There were no significant changes in weight in the group as a whole or by sex at the end of the testing period; the men lost 0.23 +/- 1.58 kg and the women lost 0.25 +/- 1.09 kg. Conclusion: The combination of observer-recorded food records and 24-h snack recalls is a valid method for measuring EI in overweight and obese individuals.