Appetite regulatory peptides in Indian Antarctic expeditioners

Solving the conundrum of intra-specific variation in metabolic rate: A multidisciplinary conceptual and methodological toolkit: New technical developments are opening the door to an understanding of why metabolic rate varies among individual animals of a species: New technical developments are opening the door to an understanding of why metabolic rate varies among individual animals of a species

Researchers from diverse disciplines, including organismal and cellular physiology, sports science, human nutrition, evolution and ecology, have sought to understand the causes and consequences of the surprising variation in metabolic rate found among and within individual animals of the same species. Research in this area has been hampered by differences in approach, terminology and methodology, and the context in which measurements are made. Recent advances provide important opportunities to identify and address the key questions in the field. By bringing together researchers from different areas of biology and biomedicine, we describe and evaluate these developments and the insights they could yield, highlighting the need for more standardisation across disciplines. We conclude with a list of important questions that can now be addressed by developing a common conceptual and methodological toolkit for studies on metabolic variation in animals.

Challenging energy balance - during sensitivity to food reward and modulatory factors implying a risk for overweight - during body weight management including dietary restraint and medium-high protein diets

Energy balance is a key concept in the etiology and prevalence of obesity and its co-morbidities, as well as in the development of possible treatments. If energy intake exceeds energy expenditure, a positive energy balance develops and the risk for overweight, obesity, and its co-morbidities increases. Energy balance is determined by energy homeostasis, and challenged by sensitivity to food reward, and to modulatory factors such as circadian misalignment, high altitude, environmental temperature, and physical activity. Food reward and circadian misalignment increase the risk for overweight and obesity, while high altitude, changes in environmental temperature, or physical activity modulate energy balance in different directions. Modulations by hypobaric hypoxia, lowering environmental temperature, or increasing physical activity have been hypothesized to contribute to body weight loss and management, yet no clear evidence has been shown. Dietary approach as part of a lifestyle approach for body weight management should imply reduction of energy intake including control of food reward, thereby sustaining satiety and fat free body mass, sustaining energy expenditure. Green tea catechins and capsaicin in red pepper in part meet these requirements by sustaining energy expenditure and increasing fat oxidation, while capsaicin also suppresses hunger and food intake. Protein intake of at least 0,8 g/kg body weight meets these requirements in that it, during decreased energy intake, increases food intake control including control of food reward, and counteracts adaptive thermogenesis. Prevention of overweight and obesity is underscored by dietary restraint, implying control of sensitivity to challenges to energy balance such as food reward and circadian misalignment. Treatment of overweight and obesity may be possible using a medium-high protein diet (0,8-1,2 g/kg), together with increased dietary restraint, while controlling challenges to energy balance.

Changes of 25-OH-Vitamin D during Overwintering at the German Antarctic Stations Neumayer II and III

Purpose

Humans in Antarctica face different environmental challenges, such as low ultra-violet radiation, which is crucial for vitamin D production in humans. Therefore we assessed changes in 25-OH-vitamin D serum concentration during 13 months of overwintering at the German Stations Neumayer II and III (2007–2012). We hypothesized that (i) 25-OH-vitamin D serum concentration would significantly decrease, (ii) changes would be affected by age, gender, baseline (i.e. pre-overwintering) fat mass, baseline 25-OH-vitamin D serum concentration, and station residence, and (iii) our results would not differ from similar previous studies in comparable high latitudes.

Materials & Methods

25-OH-vitamin D serum concentrations were determined before, after, and monthly during the campaigns from venous blood samples of n = 43 participants (28 men, 15 women). Baseline fat mass was determined via bio impedance analysis and body plethysmography. Data were analyzed for change over time, dependency on independent parameters, and after categorization for sufficiency (>50nmol/l), insufficiency (25-50nmol/l), and deficiency (<25nmol/l). Results were compared with data from similar previous studies.

Results

We found a significant decrease of 25-OH-vitamin D with dependency on month. Age, gender, fat mass, and station residence had no influence. Only baseline 25-OH-vitamin D serum concentrations significantly affected subsequent 25-OH-vitamin D values.

Conclusions

Overwinterings at the Antarctic German research stations Neumayer II and III are associated with a decrease in 25-OH-vitamin D serum concentrations, unaffected by age, gender, baseline fat mass, and station residence. Higher baseline vitamin D serum concentrations might protect from subsequent deficiencies. Residence at the Neumayer Stations may lead to lower vitamin D serum concentrations than found in other comparable high latitudes.

Beverage from Coleus aromaticus reduces leptin levels and improves appetite rating in human volunteers

OBJECTIVE

Coleus aromaticus, commonly called country borage or Indian borage, is a perennial herb grown throughout the Indian subcontinent. Traditionally, the leaves of the plant are used as a cure for cold, cough, and fever as well as to relieve pain from skin irritations. However, the appetite-enhancing potential of the herb was unexplored. Based on the encouraging results of animal studies, this study was taken up to establish the appetite-enhancing potential of Coleus aromaticus in humans by evaluating its ready-to-drink beverage.

METHODS

A homogenous and healthy group of volunteers was selected. Ready-to-drink beverages based on the herb karpurvalli (Coleus aromaticus) containing three different concentrations (12% [sensorily optimized level], 18%, and 24%) of the herb juice and a placebo beverage were evaluated with the volunteers. The fasting and postprandial levels of plasma leptin were measured, and the appetite rating on a structured visual analog scale was obtained.

RESULTS

The study revealed a significant reduction in leptin levels with 12% juice, whereas a significant increase was seen after consumption of the beverage containing 24%. A similar pattern was obtained with the structured ratings.

CONCLUSION

The appetite-enhancing effect of the beverage was best when it contained the sensorily optimized level of karpurvalli juice and confirms the results obtained in animal study. To our knowledge, this is the first study validating the appetite-enhancing potential of the herb.

Seasonal variation in the voluntary food intake of domesticated cats (Felis catus)

There are numerous reports about seasonal cycles on food intake in animals but information is limited in dogs and cats. A 4-year prospective, observational, cohort study was conducted to assess differences in food intake in 38 ad-libitum-fed adult colony cats, of various breeds, ages and genders. Individual food intake was recorded on a daily basis, and the mean daily intake for each calendar month was calculated. These data were compared with climatic data (temperature and daylight length) for the region in the South of France where the study was performed. Data were analysed using both conventional statistical methods and by modelling using artificial neural networks (ANN). Irrespective of year, an effect of month was evident on food intake (P<0.001), with three periods of broadly differing intake. Food intake was least in the summer months (e.g. June, to August), and greatest during the months of late autumn and winter (e.g. October to February), with intermediate intake in the spring (e.g. March to May) and early autumn (e.g. September). A seasonal effect on bodyweight was not recorded. Periods of peak and trough food intake coincided with peaks and troughs in both temperature and daylight length. In conclusion, average food intake in summer is approximately 15% less than food intake during the winter months, and is likely to be due to the effects of outside temperatures and differences in daylight length. This seasonal effect in food intake should be properly considered when estimating daily maintenance energy requirements in cats.

Effect of yoga or physical exercise on physical, cognitive and emotional measures in children: a randomized controlled trial

BACKGROUND

Previous studies have separately reported the effects of physical exercise and yoga in children, showing physical, cognitive and emotional benefits.

OBJECTIVES

The present randomized controlled trial assessed the effects of yoga or physical exercise on physical fitness, cognitive performance, self-esteem, and teacher-rated behavior and performance, in school children.

METHODS

98 school children between 8 to 13 years were randomized as yoga and physical exercise groups {n = 49 each; (yoga: 15 girls, group mean age 10.4 ± 1.2 years), (physical exercise: 23 girls, group mean age 10.5 ± 1.3 years)}. Both groups were blind assessed after allocation, using: (i) the Eurofit physical fitness test battery, (ii) Stroop color-word task for children, (iii) Battle's self-esteem inventory and (iv) the teachers' rating of the children's obedience, academic performance, attention, punctuality, and behavior with friends and teachers. After assessments the yoga group practiced yoga (breathing techniques, postures, guided relaxation and chanting), 45 minutes each day, 5 days a week. During this time the physical exercise group had jogging-in-place, rapid repetitive movements and relay races or games. Both groups were assessed at the end of 3 months. Data were analyzed with RM ANOVA and post-hoc tests were Bonferroni adjusted.

RESULTS

There was one significant difference between groups. This was in social self-esteem which was higher after physical exercise compared to yoga (p < 0.05). All the changes reported below are based on after-before comparisons, within each group. Both groups showed an increase in BMI, and number of sit-ups (p < 0.001). Balance worsened in the physical exercise group, while plate tapping improved in the yoga group (p < 0.001). In the Stroop task both groups showed improved color, word- and color-word naming (p < 0.01), while the physical exercise group showed higher interference scores. Total, general and parental self-esteem improved in the yoga group (p < 0.05).

CONCLUSION

Yoga and physical exercise are useful additions to the school routine, with physical exercise improving social self-esteem.

TRIAL REGISTRATION

The study was registered in the Clinical Trials Registry of India (CTRI/2012/11/003112).

A longitudinal study of the effect of Antarctic residence on energy dynamics and aerobic fitness

OBJECTIVES

To investigate the effect of Antarctic residence on energy dynamics and aerobic fitness over the course of a year in over-wintering personnel.

STUDY DESIGN

A prospective longitudinal observational study.

METHODS

A convenience sample of personnel over-wintering at Rothera Research Station in Antarctica was studied. Body weight, body fat, food intake, activity and aerobic fitness were recorded every 30 days for 1 year. Body weight, body fat and food intake were measured using weighing scales, skinfold callipers and diet records, respectively; activity was measured using accelerometer-based activity trackers and aerobic fitness using a treadmill protocol. Climate markers of temperature and sunlight hours were also recorded.

RESULTS

Twenty-one subjects took part in the study over the 12-month period. A statistically significant increase in body weight and body fat in winter was observed (p=0.012 and p=0.049, respectively). There were no statistically significant trends in activity, food intake or aerobic fitness.

CONCLUSIONS

There were significant seasonal changes in body weight and body fat, with both measures increasing in winter but no significant changes in the other main outcome measures.

Effect of appetizer administration on plasma leptin level in human volunteers

The present study aimed at evaluating the effect of appetizer administration on plasma leptin levels of human volunteers. The ginger-based appetizers, namely ginger munch, fruit munch, jeera munch and appetizer drink, developed in the Defence Food Research Laboratory were used for 45 volunteers. Leptin was analyzed using the BioSource enzyme-amplified sensitivity immunoassay kit. The fasting plasma leptin level for men and women ranged between 0.5 and 19.5 ng/ml and between 2 and 36 ng/ml, respectively. The decreased (6-16%) plasma leptin levels after consumption of appetizers indicated their appetizing effect.