Ethanol regulated preference in rats

A series of experiments evaluated the determinants of preference for mixtures of ethanol plus sucrose relative to sucrose in rats. One dipper served 10% ethanol mixed with 10% sucrose, and the second dipper served 10% sucrose. Lever presses operated each dipper according to a variable-interval 5-s schedule. In three experiments the subjects were given pre-session meals of sucrose (2.5–20 ml) or sucrose (20 ml) plus chow (5 or 10 g). Pre-session meals decreased responding maintained by sucrose but not responding maintained by ethanol mixture. In two experiments body weight was varied from 85% to 125% of the initial free-feeding values. Increases in body weight, like pre-session meals, decreased responding reinforced by sucrose, but typically did not decrease responding reinforced by ethanol mixture. Throughout most of the study, ethanol consumption remained at about 1.25 ml per half hour session (3–4 g/kg per 30 min). For example, pre-session access to ethanol mixture decreased within-session ethanol consumption, but total consumption, counting both sources, remained about 1.25 ml/session. The within-session patterns of responding also differed. Responding reinforced by ethanol mix decreased as a function of ethanol consumption, whereas responding reinforced by sucrose was relatively constant throughout the session. The simplest explanation of the results is that ethanol's pharmacological consequences regulated preference.     

Factors Associated with Calcium Absorption in Postmenopausal Women: A Post Hoc Analysis of Dual-Isotope Studies

Reduced calcium absorption is a risk factor for osteoporosis. This study examined factors associated with fractional calcium absorption (FCA) and net calcium absorption in postmenopausal women in a post hoc analysis of three completed dual-isotope studies. Data were analyzed from 50 postmenopausal women undergoing 121 inpatient research visits in three studies evaluating changes in FCA related to correction of vitamin D insufficiency (n=19), use of proton pump inhibitors (n=21), and use of aromatase inhibitors to treat breast cancer (n=10). Net calcium absorption was the product of FCA and total calcium intake in milligrams per day. Variables included subjects' age, race, body mass index, serum calcium, creatinine, parathyroid hormone, 1,25-dihydroxyvitamin D, 25-hydroxyvitamin D, and habitual intake of kilocalories, protein, fat, carbohydrate, fiber, calcium, iron, magnesium, oxalate, phosphorus, potassium, and vitamin D based on outpatient diet diaries. In multivariate models, subjects' age, dietary intake of kilocalories, carbohydrates, fat, fiber, calcium, and potassium were significant predictors of FCA. In multiple variable models predicting net calcium absorption, dietary intake of kilocalories, fat, fiber, calcium, potassium, and serum 1,25-dihydroxyvitamin D were significant. The square of the correlation between actual and predicted values (an approximation of R²) was 0.748 for FCA and 0.726 for net calcium absorption. Similar to other studies, this study found that age, 1,25-dihydroxyvitamin D, and dietary calcium and fat were associated with calcium absorption. Dietary intake of kilocalories, carbohydrates, and potassium were new factors that were significantly associated with FCA and net calcium absorption. In summary, the study suggests that several dietary habits play a role in calcium absorption, beyond vitamin D and calcium.     

Drinking to our health: can beverage companies cut calories while maintaining profits?

Carbonated soft drinks and other beverages make up an increasing percentage of energy intake, and there are rising public health concerns about the links between consumption of sugar-sweetened beverages and weight gain, obesity, and other cardiometabolic problems. In response, the food and beverage industry claims to be reformulating products, reducing package or portion sizes and introducing healthier options. Comparative analysis on various changes and their potential effects on public health are needed. We conduct a case study using the two largest and most influential producers of sweetened beverages, The Coca-Cola Company and PepsiCo Inc., who together control 34% of the global soft drink market, examining their product portfolios globally and in three critical markets (the United States, Brazil and China) from 2000 to 2010. On a global basis, total revenues and energy per capita sold increased, yet the average energy density (kJ 100 mL(-1) ) sold declined slightly, suggesting a shift to lower-calorie products. In the United States, both total energy per capita and average energy density of beverages sold decreased, while the opposite was true in the developing markets of Brazil and China, with total per capita energy increasing greatly in China and, to a lesser extent, in Brazil.     

Pregnancy Nutritional Indices and Birth Weight After Roux-en-Y Gastric Bypass

Background  Maternal metabolic profile and nutritional course of pregnancy after bariatric interventions is incompletely known. Their impact on birth weight has also not been hitherto addressed. Aiming to document such variables, a retrospective study was undertaken. Methods  Women previously submitted to silastic ring Roux-en-Y gastric bypass, who conceived after 0–5 years (n = 14), were investigated. Intake of selected macro- and micronutrients, representative laboratory measurements, and correlation of these findings with birth weight and time to conception was documented. Results  Mean calorie intake was restricted to about 1,800 kcal/day. Protein (71 ± 17 g/day) and supplementary iron (60 mg/day) were barely adequate, and calcium and vitamin B₁₂ did not meet current recommendations, only folic acid being optimal. Biochemical monitoring reflected these inconsistencies, with occasional low values for serum albumin (4.1 ± 0.4 g/dL), hemoglobin (11.4 ± 1.5 g/dL), iron (78 ± 50 μg/dL) and vitamin B₁₂ (193 ± 102 pg/mL) but not folate. Lipids, glucose, and uric acid were much better than before the anti-obesity intervention. Reduced plasma lipids, glucose, and uric acid were associated with larger birth weight, albeit within the normal range. Conclusions  (1) Anemia as well as additional nutritional deficits during pregnancy were not totally eliminated, despite dietary guidance and micronutrient supplementation; (2) alleviation of metabolic comorbidities was demonstrated, and improved normalization predicted higher birth weight; (3) energy and folate intake was sufficient, but other nutrients probably did not reach ideal levels; (4) recent dietary guidelines for this population represent a step forward, but additional studies are needed.     

热量和脂肪对健康人胃食管反流的影响

目的 评估饮食脂肪和热量对健康人胃食管酸反流的影响.方法 选择25例健康志愿者,先做食管测压,先后2次服用低脂肪餐和高脂肪餐,每次记录餐后6 h食管pH值.结果 健康志愿者在2种热量相等的低脂肪和高脂肪含量的试餐后,pH＜4总反流时间百分率(2.83±3.33%,3.15 4±-3.05%),反流时间＞5 min的反流次数(0.32 ±0.627,0.4±0.866)及反流次数(15.96±15.54,16.6±14.07)的比较,均没有显著性差异(P＞0.05).结论 在同热量含量下,食物中脂肪含量对健康人餐后6 h酸反流没有影响.     

Effects of dietary restriction and exercise on the age-related pathology of the rat

Intervention of the aging process is an effective, experimental means of uncovering the bases of aging. The most efficacious and commonly used intervention used to retard the aging processes is dietary restriction (DR). It increases mean and maximum life spans, delays the appearance, frequency, and severity of many age-related diseases, and more importantly, attenuates much of the physiological decline associated with age. Although the subject of intense research, the mechanism by which DR alters the aging processes is still unknown. Physical exercise is another effective intervention shown to affect aging phenomena, especially when applied in combination with DR. Mild exercise in concert with DR is beneficial, but vigorous exercise coupled with DR could be deleterious. With regard to pathology, exercise generally exerts a salutary influence on age-related diseases, both neoplastic and non-neoplastic, and this effect may contribute to the increase in median life span seen with exercised rats. Exercise coupled with 40% DR was found to suppress the incidence of fatal neoplastic disease compared to the sedentary DR group. Exercise with mild DR suppressed the incidence of multiple fatal disease and chronic nephropathy, and also delayed the occurrence of many age-related lesions compared to the ad libitum (AL) control group. However, these effects may have little bearing on the aging process per se, as maximum life span is only minimally affected. Although not as intensively studied as DR, results from studies that utilize exercise as a research probe, either alone or in combination with DR, have helped to assess the validity of proposed mechanisms for DR and aging itself. Neither the retardation of growth rate nor the increase in physical activity, observed with either exercise or DR, appear to contribute to the anti-aging action of DR. Moreover, results from lifelong exercise studies indicate that the effects of DR do not depend upon changes in energy availability or metabolic rate. The mechanisms involving effects on adiposity or immune function are also inadequate explanations for the action of DR on aging. Of the proposed mechanisms, only one, as postulated by the Oxidative Stress Hypothesis of Aging, tenably accounts for the known effects of DR and exercise on aging.     

The Relationship between Health-Related Knowledge and Sugar-Sweetened Beverage Intake among US Adults

Because there is limited information on associations between health-related knowledge and sugar-sweetened beverage (SSB) intake, our cross-sectional study examined this question using the 2010 HealthStyles Survey data for 3,926 adults (aged ≥18 years). Multivariable logistic regression analysis was used to estimate the adjusted odds ratios and 95% CIs for drinking SSBs ≥2 times per day. About 31% of adults consumed SSBs ≥1 time per day, with 20% doing so ≥2 times per day. About eight of 10 adults agreed that drinking SSBs can contribute to weight gain, yet, eight of 10 adults in this study did not know the actual kilocalorie content of a 24-oz fountain soda. After controlling for age, sex, race/ethnicity, education level, annual household income, and geographic region, the odds for drinking SSBs ≥2 times per day were significantly higher among adults who neither agreed nor disagreed (ie, were neutral) that drinking SSBs can contribute to weight gain (odds ratio 1.61, 95% CI 1.15 to 2.25 vs agree); however, knowledge about the energy content of regular soda was not associated with SSB intake. Our finding that knowledge about the adverse effects of SSB intake is significantly associated with SSB intake among adults suggests that health education regarding the potential contribution of excess energy intake from SSBs to weight gain could contribute to lowered consumption and lower rates of obesity. Although knowledge about the kilocalorie content of regular soda was unrelated to SSB intake, health education on the kilocalorie content of SSBs may still be beneficial because most adults did not know the actual kilocalorie content of SSBs. Longitudinal studies are needed to explore associations between knowledge about energy provided by SSBs and SSB intake.