Impact of a comprehensive nutrition and lifestyle education intervention on body weight and health-related outcomes in morbidly-obese Hispanic-Americans following laparoscopic Roux-en-Y gastric bypass

As morbid obesity increasingly affects Hispanic-Americans, the incidence of Roux-en-Y gastric bypass procedures (RYGB) among this population rises. Prospective research on the impact of postoperative educational interventions focused on Hispanic- Americans is needed to prevent premature weight loss plateau, weight regain, nutritional deficiencies, and relapse of obesity-related comorbidities. This randomized-controlled study evaluated the impact of a comprehensive nutrition and lifestyle education intervention (6 biweekly postoperative sessions that incorporated motivational strategies for behavioral change) as compared to a non-comprehensive approach (printed guidelines for healthy lifestyle). The variables to consider are body weight, obesity-related comorbidities (depression, diabetes, dyslipidemia, and others), nutrient status, physical activity, and eating habits in 144 morbidly-obese adult Hispanic-Americans 6 to 12 months following RYGB. Patients were randomly assigned to either the comprehensive intervention (n=72) or the comparison group (n=72). Participants (mean age 44.5 ± 13.5 years) were mainly Cuban-born females (83.3%). Intervention sessions attendance was 64%. At 12 months, both groups lost weight significantly, but those in the comprehensive intervention experienced greater excess weight loss than those in the comparison group (80% vs. 64% from preoperative excess weight, P<.001). Intervention participants were significantly more involved in physical activity (+ 14 min/week vs. – 4 min/week), had decreased depression, joint illness, and required less medication for comorbidities than comparison participants. Additionally, those in the comprehensive intervention had sustained supplement intake experiencing less folate deficiency (P=.014). The non-comprehensive intervention group significantly decreased their protein and supplement intake compared to the intervention group. Patients in the comprehensive intervention had significantly better eating habits reflected by fewer episodes of dumping syndrome, constipation, and night eating, than those in the comparison group who reported greater eating in response to negative emotions (P=.003). These findings support the importance of a comprehensive educational approach to achieve more effective weight reduction and health-related outcomes to prevent relapse of obesity-related comorbidities and nutritional deficiencies in Hispanic-Americans 6 to 12 months following RYGB.

Psychological and cognitive factors that influence post -exercise energy intake in normal weight and overweight sedentary males

Physical activity is recommended to facilitate weight management. However, some individuals may be unable to successfully manage their weight due to certain psychological and cognitive factors that trigger them to compensate for calories expended in exercise. The primary purpose of this study was to evaluate the effect of moderate-intensity exercise on lunch and 12-hour post-exercise energy intake (PE-EI) in normal weight and overweight sedentary males. Perceived hunger, mood, carbohydrate intake from beverages, and accuracy in estimating energy intake (EI) and energy expenditure (EE) were also assessed. The study consisted of two conditions, exercise (treadmill walking) and rest (sitting), with each participant completing each condition, in a counterbalanced-crossover design on two days. Eighty males, mean age 30 years (SD=8) were categorized into five groups according to weight (normal-/overweight), dietary restraint level (high/low), and dieting status (yes/no). Results of repeated measures, 5x2 ANOVA indicated that the main effects of condition and group, and the interaction were not significant for lunch or 12-hour PE-EI. Among overweight participants, dieters consumed significantly (p<0.05) fewer calories than non-dieters at lunch (M=822 vs. M=1149) and over 12 hours (M=1858 vs. M =2497). Overall, participants’ estimated exercise EE was significantly (p<0.01) higher than actual exercise EE, and estimated resting EE was significantly (p<0.001) lower than actual resting EE. Participants significantly (p<0.001) underestimated EI at lunch on both experimental days. Perceived hunger was significantly (p<0.05) lower after exercise (M=49 mm, SEM=3) than after rest (M=57 mm, SEM=3). Mood scores and carbohydrate intake from beverages were not influenced by weight, dietary restraint, and dieting status. In conclusion, a single bout of moderate-intensity exercise did not influence PE-EI in sedentary males in reference to weight, dietary restraint, and dieting status, suggesting that this population may not be at risk for overeating in response to exercise. Therefore, exercise can be prescribed and used as an effective tool for weight management. Results also indicated that there was an inability to accurately estimate EI (ad libitum lunch meal) and EE (60 minutes of moderate-intensity exercise). Inaccuracies in the estimation of calories for EI and EE could have the potential to unfavorably impact weight management.

Psychological and Cognitive Factors that Influence Post-Exercise Energy Intake in Normal Weight and Overweight Sedentary Males

The primary purpose of this study was to evaluate the effects of a single bout of moderate-intensity exercise on acute (ad libitum lunch) post-exercise energy intake (PE-EI) and 12-hour energy intake in normal-weight and overweight sedentary males. Accuracy in estimating energy intake (EI) and energy expenditure (EE), solid vs. liquid carbohydrate intake, mood, and perceived hunger were also assessed. The study consisted of two conditions, exercise and rest, with each subject participating in each condition, in a counterbalanced-crossover design on two days. The participants were randomly assigned to either the exercise or resting (seated) control condition on the first day of the experiment, and then the condition was reversed on the second day. Exercise consisted of walking on a treadmill at moderate-intensity for 60 minutes. Eighty males, mean age 30+8 years were categorized into five groups according to weight status (overweight/normal-weight), dietary restraint status (high/low), and dieting status (yes/no). The main effects of condition and group, and the interaction were not significant for acute (lunch) or 12-hour PE-EI. Overall, participants estimated EE for exercise at 46% higher than actual exercise EE, and they estimated EE for rest by 45% lower than actual resting EE. Participants significantly underestimated EI at lunch on both the exercise and rest days by 43% and 44%, respectively. Participants with high restraint were significantly better at estimating EE on the exercise day, and better at estimating EI on the rest day. Mood, perceived hunger, and solid vs. liquid carbohydrate intake were not influenced by dietary restraint, weight, or dieting status. In conclusion, a single bout of moderate-intensity exercise did not influence PE-EI in sedentary males in reference to dietary restraint, weight, and dieting status. Results also suggested that among sedentary males, there is a general inability to accurately estimate calories for moderate-intensity physical activity and EI. Inaccurate estimates of EE and EI have the potential to influence how males manage their weight.

Shoot architecture and growth in the south Florida wet prairie macrophyte, Eleocharis cellulosa

Eleocharis cellulosa is a dominant macrophyte in Everglades wet prairie communities. The development of the shoot system in the genus has been described as sympodial but with an unusual adnation of the horizontal and vertical shoots. The growth pattern of E. cellulosa was studied from field collected plants and plants grown in the greenhouse. Plants were extracted and measurements of horizontal and vertical shoot were taken. Dissections, paraffin sectioning and SEM's were used to examine shoot structure in early developmental stages. E. cellulosa was transplanted from the field to the greenhouse and different levels of Nitrogen and Phosphorus were added to determine how it responded phenotypically. Dissections and microscopy showed that growth of the vertical shoots of E. cellulosa is sympodial, while growth of the horizontal shoots is mixed, beginning monopodially then transforming to sympodial growth. Additions of nutrients did not have any effect on the morphology of E. cellulosa.

Root:Shoot Ratio and Specific Leaf Area Along an Elevational Gradient in the Peruvian Andes

Andean montane forests are one of the most diverse ecosystems on Earth, but are also highly vulnerable to climate change. Therefore, the link between plant distribution and ecosystem productivity is a critical point to investigate in these ecosystems. Are the patterns in productivity observed in montane forest due to species turnover along the elevational gradients? Methodological constraints keep this question unanswered. Also, despite their importance, belowground biomass remains poorly quantified and understood. I measured two plant functional traits in seedlings, root:shoot ratio and specific leaf area, to identify different strategies in growth and biomass allocation across elevations. A tradeoff in specific leaf area with elevation was found in only one species, and no generalized directional change was detected with elevations for root:shoot ratio. Lack of information for the ontogeny of the measured plant traits could confounding the analysis.