scholarly journals The Human Body May Buffer Small Differences in Meal Size and Timing during a 24-h Wake Period Provided Energy Balance Is Maintained

2003 ◽  
Vol 133 (9) ◽  
pp. 2748-2755 ◽  
Author(s):  
Ulf Holmbäck ◽  
Arne Lowden ◽  
Torbjörn Åkerfeldt ◽  
Maria Lennernäs ◽  
Leif Hambraeus ◽  
...  
Keyword(s):  
2013 ◽  
Vol 305 (5) ◽  
pp. R499-R505 ◽  
Author(s):  
Hyun-Ju Kim ◽  
Eun-Young Park ◽  
Mi-Jeong Oh ◽  
Sung-Soo Park ◽  
Kyung-Ho Shin ◽  
...  

Administration of metformin is known to reduce both body weight and food intake. Although the hypothalamus is recognized as a critical regulator of energy balance and body weight, there is currently no evidence for an effect of metformin in the hypothalamus. Therefore, we sought to determine the central action of metformin on energy balance and body weight, as well as its potential involvement with key hypothalamic energy sensors, including adenosine monophosphate-activated protein kinase (AMPK) and S6 kinase (S6K). We used meal pattern analysis and a conditioned taste aversion (CTA) test and measured energy expenditure in C56BL/6 mice administered metformin (0, 7.5, 15, or 30 μg) into the third ventricle (I3V). Furthermore, we I3V-administered either control or metformin (30 μg) and compared the phosphorylation of AMPK and S6K in the mouse mediobasal hypothalamus. Compared with the control, I3V administration of metformin decreased body weight and food intake in a dose-dependent manner and did not result in CTA. Furthermore, the reduction in food intake induced by I3V administration of metformin was accomplished by decreases in both nocturnal meal size and number. Compared with the control, I3V administration of metformin significantly increased phosphorylation of S6K at Thr389 and AMPK at Ser485/491 in the mediobasal hypothalamus, while AMPK phosphorylation at Thr172 was not significantly altered. Moreover, I3V rapamycin pretreatment restored the metformin-induced anorexia and weight loss. These results suggest that the reduction in food intake induced by the central administration of metformin in the mice may be mediated by activation of S6K pathway.


Author(s):  
Atsumasa Yoshida ◽  
Yasuhiro Shimazaki ◽  
Shinichi Kinoshita ◽  
Ryota Suzuki

There is an increased world attention on environmental issues with the global trend of environmental degradation. Especially thermal environment was highly concerned as human safety. We have been focused on creation of amenity environment with energy-saving way. This study is uncommonly dealing with human feeling for human thermal comfort, that is to say quantification of environment has been done. The feeling of comfort is mixed sense and can be totally easier to improve compared with straightforward way, and this may lead to energy and cost saving way of improvement. Moreover, this is human-oriented and can reflect humans’ wishes. Since thermal comfort index is useful tool for understanding the present state and evaluating the impact of countermeasures, effectiveness of human thermal load which is thermal comfort index based on energy balance of human body was examined. The human thermal comfort around the human body in outdoor is influenced by six dominant factors; air temperature, humidity, solar radiation, wind speed, metabolism and clothing. The difference between indoor and outdoor is expressed mainly as non-uniform and unsteady. Therefore, the unsteady responses of each dominant factors were examined and clarified human thermal load is quite good estimation of human thermal comfort. In steady state and even in unsteady state, thermal comfort can be obtained by using human thermal load on the whole. The reason is human thermal load consider the amount of physiology and also weather parameters. In the process of creating energy balance model of human, clothing material was deeply considered. For establishing better thermal environment, clothing material is of great use, because clothing material has an impact on thermal exchange between exterior environment and human body and more easy way to improve in 6 factors. The traditional treatment of clothing in human science was only resistance of heat transfer and this was not enough for all clothing effects. In daily life, effect of humidity exists and moisture property is required. Moreover color of material has impact on energy balance in clothing material. In order to show a way of better thermal environment, the heat and the moisture transfer coefficients on clothing material, radiative properties, and additional properties such as convection heat transfer coefficient were measured, and energy flow of clothing material was totally investigated. Finally, the effects of clothing material for human thermal comfort were predicted and this energy balance human model has become much better model.


2012 ◽  
Vol 303 (4) ◽  
pp. E496-E503 ◽  
Author(s):  
Scott E. Kanoski ◽  
Shiru Zhao ◽  
Douglas J. Guarnieri ◽  
Ralph J. DiLeone ◽  
Jianqun Yan ◽  
...  

Leptin receptor (LepRb) signaling in the hindbrain is required for energy balance control. Yet the specific hindbrain neurons and the behavioral processes mediating energy balance control by hindbrain leptin signaling are unknown. Studies here employ genetic [adeno-associated virally mediated RNA interference (AAV-RNAi)] and pharmacological methodologies to specify the neurons and the mechanisms through which hindbrain LepRb signaling contributes to the control of food intake. Results show that AAV-RNAi-mediated LepRb knockdown targeting a region encompassing the mNTS and area postrema (AP) (mNTS/AP LepRbKD) increases overall cumulative food intake by increasing the size of spontaneous meals. Other results show that pharmacological hindbrain leptin delivery and RNAi-mediated mNTS/AP LepRb knockdown increased and decreased the intake-suppressive effects of intraduodenal nutrient infusion, respectively. These meal size and intestinally derived signal amplification effects are likely mediated by LepRb signaling in the mNTS and not the AP, since 4th icv and mNTS parenchymal leptin (0.5 μg) administration reduced food intake, whereas this dose did not influence food intake when injected into the AP. Overall, these findings deepen the understanding of the distributed neuronal systems and behavioral mechanisms that mediate the effects of leptin receptor signaling on the control of food intake.


Author(s):  
L. V. Zhuravlyova ◽  
Yu. D. Stoianova

The combination of diabetes mellitus type 2 and gout is common. It has been established that prolonged hyperuricemia leads to insulin resistance and suppresses the effects of insulin, which is why the study of pathogenetic links in the formation of metabolic disorders in synergistic pathologies is relevant. AMPK has been shown to be a regulator of cell energy balance, which plays an important role in preventing the development of insulin resistance. The purpose of this review is to determine the impact of AMPK on carbohydrate, lipid and purine metabolism in patients with diabetes mellitus type 2 and gout. The realization of the effects of AMPK on metabolic processes in the human body occurs in two main ways — inhibition of anabolism and stimulation of catabolism, which will be discussed in the article. It is advisable to consider the mechanisms of action of indirect activators of AMPK as potential components for the comprehensive treatment of patients with metabolic disorders. The mechanisms of activation and inhibition of AMPK are not investigated enough, but it is known that AMPK plays a significant role in the main metabolic processes in the human body. The mechanisms of cell sensitivity to most energy‑containing molecules and substances directly depend on the AMPK activation degree. The presence of these dependencies may be evaluated in the case of metabolic diseases. Thus, further study of the effects of AMPK and its influence on carbohydrate, lipid and purine metabolism is necessary, due to the possibility of predicting the formation of insulin resistance, the severity of diabetes mellitus type 2 in combination with gout, and optimizing treatment in patients with comorbid pathology.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246569
Author(s):  
Yakshkumar Dilipbhai Rathod ◽  
Mauricio Di Fulvio

The feeding pattern and control of energy intake in mice housed in groups are poorly understood. Here, we determined and quantified the normal feeding microstructure of social male and female mice of the C57BL/6J genetic background fed a chow diet. Mice at 10w, 20w and 30w of age showed the expected increase in lean and fat mass, being the latter more pronounced and variable in males than in females. Under ad libitum conditions, 20w and 30w old females housed in groups showed significantly increased daily energy intake when adjusted to body weight relative to age-matched males. This was the combined result of small increases in energy intake during the nocturnal and diurnal photoperiods of the day without major changes in the circadian pattern of energy intake or spontaneous ambulatory activity. The analysis of the feeding microstructure suggests sex- and age-related contributions of meal size, meal frequency and intermeal interval to the control of energy intake under stable energy balance, but not under negative energy balance imposed by prolonged fasting. During the night, 10-20w old females ate less frequently bigger meals and spent more time eating them resulting in reduced net energy intake relative to age-matched males. In addition, male and female mice at all ages tested significantly shortened the intermeal interval during the first hours of re-feeding in response to fasting without affecting meal size. Further, 20-30w old males lengthened their intermeal interval as re-feeding time increased to reach fed-levels faster than age-matched females. Collectively, our results suggest that the physiological mechanisms controlling meal size (satiation) and the non-eating time spent between meals (satiety) during stable or negative energy balance are regulated in a sex- and age-dependent manner in social mice.


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