Self-Reported Energy Intake and Energy Expenditure in Elderly Women

The elderly are a growing population; however, limited information concerning energy requirements of the elderly is available. Dietary intake data have been collected in research and clinical settings to determine the intakes of energy and nutrients, but the accuracy of dietary intake data has been difficult to verify. Studies using doubly labeled water have suggested that dietary energy intake is underreported by obese subjects (1), adolescents (2), and athletes (3). Diet records were collected for 6 to 14 days in these studies (1), (2), (3). Elderly subjects have also underreported energy intake compared with total energy expenditure (TEE), either measured (4), (5), (6) or predicted (7). However, these studies only collected dietary data for 3 or 4 days, while energy expenditure was measured for 10 to 14 days using doubly labeled water. It is generally accepted that a major source of random variation in dietary energy can be ascribed to a person\u27s day-to-day variation in energy consumption, which averages 20% to 30% (8). This random variation decreases as the square root of the number of study days increases, such that it is approximately 10% for a 7-day record (9). Thus, some of the variability in self-reported energy intake may be attributable to the limited number of observations taken in previous studies of elderly women. To our knowledge, a comparison of TEE using doubly labeled water and concurrent diet records for a full week for elderly women has not been reported previously. The purpose of our study was to determine whether a complete recording of dietary intake would improve the accuracy of and reduce the individual variation in self-reported dietary energy intake compared with energy expenditure measurements using doubly labeled water

Dietary Intake and Energy Expenditure of Female Collegiate Swimmers During Decreased Training Prior to Competition

Swimmers, like all athletes, require a well-balanced diet with adequate energy intake for normal daily activities and the demands of training and competition. Investigators have typically studied nutritional status of athletes during heavy or peak training (1), (2). These studies generally show low levels of energy intake relative to expenditure, and carbohydrate intake also well below recommendations. However, several studies of the effects of exercise on energy intake have shown that as exercise energy expenditure increases or decreases, dietary intake tends to remain the same (3), (4), (5). Because training volume varies with the competitive season, it is important to investigate dietary intake at different levels of training. One period of training during which nutritional intake has not been studied is during taper, a period of decreased training before an athletic event to improve mental and physical readiness for competition (6). An important issue during this period is whether the discrepancy between energy intake and expenditure previously reported during heavy training is maintained during a period of reduced training. Another consideration is the number of reduced-fat food products consumed by female athletes. (In recent years, there has been an overwhelming increase in the availability of low-fat and fat-free food products.) Increased use of these foods may contribute to the increased carbohydrate intake observed in some recent studies of female athletes (7), (8), (9), which contrasts with earlier studies suggesting that carbohydrate intakes of female endurance athletes are 14% to 24% lower than recommended (1)

Aberrant Water Homeostasis Detected by Stable Isotope Analysis

While isotopes are frequently used as tracers in investigations of disease physiology (i.e., 14C labeled glucose), few studies have examined the impact that disease, and disease-related alterations in metabolism, may have on stable isotope ratios at natural abundance levels. The isotopic composition of body water is heavily influenced by water metabolism and dietary patterns and may provide a platform for disease detection. By utilizing a model of streptozotocin (STZ)-induced diabetes as an index case of aberrant water homeostasis, we demonstrate that untreated diabetes mellitus results in distinct combinations, or signatures, of the hydrogen (δ2H) and oxygen (δ18O) isotope ratios in body water. Additionally, we show that the δ2H and δ18O values of body water are correlated with increased water flux, suggesting altered blood osmolality, due to hyperglycemia, as the mechanism behind this correlation. Further, we present a mathematical model describing the impact of water flux on the isotopic composition of body water and compare model predicted values with actual values. These data highlight the importance of factors such as water flux and energy expenditure on predictive models of body water and additionally provide a framework for using naturally occurring stable isotope ratios to monitor diseases that impact water homeostasis

Tracking Cats: Problems with Placing Feline Carnivores on δ18O, δD Isoscapes

Several felids are endangered and threatened by the illegal wildlife trade. Establishing geographic origin of tissues of endangered species is thus crucial for wildlife crime investigations and effective conservation strategies. As shown in other species, stable isotope analysis of hydrogen and oxygen in hair (δD(h), δ(18)O(h)) can be used as a tool for provenance determination. However, reliably predicting the spatial distribution of δD(h) and δ(18)O(h) requires confirmation from animal tissues of known origin and a detailed understanding of the isotopic routing of dietary nutrients into felid hair.We used coupled δD(h) and δ(18)O(h) measurements from the North American bobcat (Lynx rufus) and puma (Puma concolor) with precipitation-based assignment isoscapes to test the feasibility of isotopic geo-location of felidae. Hairs of felid and rabbit museum specimens from 75 sites across the United States and Canada were analyzed. Bobcat and puma lacked a significant correlation between H/O isotopes in hair and local waters, and also exhibited an isotopic decoupling of δ(18)O(h) and δD(h). Conversely, strong δD and δ(18)O coupling was found for key prey, eastern cottontail rabbit (Sylvilagus floridanus; hair) and white-tailed deer (Odocoileus virginianus; collagen, bone phosphate).Puma and bobcat hairs do not adhere to expected pattern of H and O isotopic variation predicted by precipitation isoscapes for North America. Thus, using bulk hair, felids cannot be placed on δ(18)O and δD isoscapes for use in forensic investigations. The effective application of isotopes to trace the provenance of feline carnivores is likely compromised by major controls of their diet, physiology and metabolism on hair δ(18)O and δD related to body water budgets. Controlled feeding experiments, combined with single amino acid isotope analysis of diets and hair, are needed to reveal mechanisms and physiological traits explaining why felid hair does not follow isotopic patterns demonstrated in many other taxa

Physical Activity, Functional Ability, and Obesity in Older Adults: A Gender Difference

Disability, institutionalization, and loss of independence may be directly caused or exacerbated by physical inactivity and obesity. The purpose of the current cross-sectional survey was to explore the impact of gender and obesity on functional ability tasks, physical activity, and psychosocial factors in older adults. Participants comprised 964 University retirees (55% female, mean age = 75.3 years, SD = 6.7 years) with a mean body mass index (BMI) of 26.1 kg/m2 (SD = 4.7 kg/m2). Results revealed significant gender and BMI interaction effects. Women were less active than men and obese women were most functionally impaired, particularly in activities that target lower extremity function, regardless of weight status. These findings suggest that physical activity interventions for older adults should focus on exercises that improve functional ability and are tailored to meet individual needs while considering weight and gender. Type, intensity, frequency, and duration of exercises should be individualized to limit injuries and improve functional ability and physical activity adherence

Longitudinal Change in Physical Activity and Disability in Adults

Objectives: To prospectively examine whether physical activity or change in physical activity increases or decreases the risk of disability later in life. Methods: Tobit regression models were used to examine the effect of physical activity at baseline and change from baseline on disability 10 and 20 years later in 6913 adults. Results: Increasing recreational physical activity was associated with reduced risk of disability whereas reducing recreational physical activity increased the risk of disability after 10 years. Conclusions: The analyses reveal a protective effect of sustained physical activity on disability among adults

Dog Ownership, Functional Ability, and Walking in Community-Dwelling Older Adults

Background: Regular walking improves overall health and functional ability of older adults, yet most are sedentary. Dog ownership/pet responsibility may increase walking in older adults. Goals of this study were to identify factors that influence older adult walking and compare physical activity, functional ability and psychosocial characteristics by dog ownership status. Methods: In this cross-sectional study, older adults (65−95 years of age, n = 1091) completed and returned questionnaires via postal mail. Measures included: Physical Activity Scale for the Elderly, Physical Functioning Questionnaire and Theory of Planned Behavior Questionnaire. Results: Dog owner/dog walkers (n = 77) reported significantly (P \u3c .05) more total walking, walking frequency, leisure and total physical activity and higher total functional ability than dog owner/nondog walkers (n = 83) and nondog owners (n = 931). Dog owner/nondog walkers reported lower intention and perceived behavioral control and a less positive attitude than dog owner/dog walkers (P \u3c .05). Conclusions: Dog owner/dog walkers were significantly different than the nondog walker groups in nearly every study variable. Many dog owners (48.1%) reported walking their dogs regularly and the dog owner/dog walkers participated in nearly 50% more total walking than the 2 nondog walking groups, suggesting that pet obligation may provide a purposeful activity that motivates some older dog owners to walk

Physical Activity and Function in Older Adults: Theory of Planned Behavior

Objective: To assess the theory of planned behavior (TPB) and TPB with functional ability to explain intention and self-reported physical activity (PA) behavior of older adults. Methods: A survey was mailed to 2056 retirees from a large Midwestern university. Results: Structural equation modeling revealed that the TPB plus functional ability explained an additional 11% variance than the TPB alone in older adult PA and functional ability was the best predictor of PA (beta = .53, P\u3c.05). Conclusions: Functional ability appears to be an important predictor of PA behavior and should be included when designing PA programs for older adults