Negative energy balance during military training: the role of contextual limitations

The initial period of lactation in domestic ruminants is usually characterised by both hyperphagia and negative energy balance (Barber et al, 1997). The factors regulating the hyperphagia of lactation are not well understood. Leptin is a peptide hormone which is secreted by adipocytes, and which acts on a number of neuropeptides and receptors in the hypothalamus to regulate appetite and energy balance (Spiegelman and Flier, 2001). The aim of this study was to investigate the role of leptin in the hyperphagia of lactation in sheep.

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Fat specific adipose triglyceride lipase is necessary for iron-mediated lipolysis and lipid mobilization in response to negative energy balance

10.1101/2021.08.05.455308 ◽

2021 ◽

Author(s):

Alicia R Romero ◽

Andre Mu ◽

Janelle S Ayres

Keyword(s):

Energy Balance ◽

Negative Energy ◽

Activity Level ◽

Negative Energy Balance ◽

Whole Body ◽

Adipose Triglyceride Lipase ◽

Dietary Iron ◽

Lipid Mobilization ◽

Triglyceride Lipase

Maintenance of energy balance is essential for the overall health of an organism. In mammals, both negative and positive energy balance are associated with disease states. To maintain their energy balance within a defined homeostatic setpoint, mammals have evolved complex regulatory mechanisms that control energy intake and expenditure. Traditionally, studies have focused on understanding the role of macronutrient physiology in energy balance. In the present study, we examined the role of the essential micronutrient iron in regulating energy balance. Using a dietary model, we found that a short course of excess dietary iron caused a negative energy balance resulting in a severe whole body wasting phenotype. This disruption in energy balance was due to an iron dependent increase in energy expenditure caused by a heightened basal metabolic rate and activity level. Using a transgenic mouse model lacking adipose triglyceride lipase (ATGL) specifically in fat tissue, we found that to meet the increased energetic demands, dietary iron caused increased lipid utilization that required fat specific ATGL-mediated lipid mobilization and wasting of subcutaneous white adipose tissue deposits. When fed dietary iron, mice lacking fat-specific ATGL activity were protected from fat wasting, and developed a severe cachectic response that is necessary to meet the increased energetic demands caused by the dietary regimen. Our work highlights the multi-faceted role of iron regulation of organismal metabolism and provides a novel in vivo mechanism for micronutrient control of lipolysis that is necessary for regulating mammalian energy balance.

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Exertional fatigue, sleep loss, and negative energy balance increase susceptibility to hypothermia

Journal of Applied Physiology ◽

10.1152/jappl.1998.85.4.1210 ◽

1998 ◽

Vol 85 (4) ◽

pp. 1210-1217 ◽

Cited By ~ 58

Author(s):

Andrew J. Young ◽

John W. Castellani ◽

Catherine O’Brien ◽

Ronald L. Shippee ◽

Peter Tikuisis ◽

...

Keyword(s):

Energy Balance ◽

Body Temperature ◽

Cold Exposure ◽

Military Training ◽

Sleep Loss ◽

Negative Energy ◽

Negative Energy Balance ◽

Air Exposure ◽

Cold Air ◽

Tissue Insulation

The purpose of this study was to determine how chronic exertional fatigue and sleep deprivation coupled with negative energy balance affect thermoregulation during cold exposure. Eight men wearing only shorts and socks sat quietly during 4-h cold air exposure (10°C) immediately after (<2 h, A) they completed 61 days of strenuous military training (energy expenditure ∼4,150 kcal/day, energy intake ∼3,300 kcal/day, sleep ∼4 h/day) and again after short (48 h, SR) and long (109 days, LR) recovery. Body weight decreased 7.4 kg from before training to A, then increased 6.4 kg by SR, with an additional 6.4 kg increase by LR. Body fat averaged 12% during A and SR and increased to 21% during LR. Rectal temperature (Tre) was lower before and during cold air exposure for A than for SR and LR. Tre declined during cold exposure in A and SR but not LR. Mean weighted skin temperature (T sk) during cold exposure was higher in A and SR than in LR. Metabolic rate increased during all cold exposures, but it was lower during A and LR than SR. The mean body temperature (0.67 Tre + 0.33T sk) threshold for increasing metabolism was lower during A than SR and LR. Thus chronic exertional fatigue and sleep loss, combined with underfeeding, reduced tissue insulation and blunted metabolic heat production, which compromised maintenance of body temperature. A short period of rest, sleep, and refeeding restored the thermogenic response to cold, but thermal balance in the cold remained compromised until after several weeks of recovery when tissue insulation had been restored.

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Regulation of Food Intake and Gonadotropin-Releasing Hormone/Luteinizing Hormone during Lactation: Role of Insulin and Leptin

Endocrinology ◽

10.1210/en.2009-0190 ◽

2009 ◽

Vol 150 (9) ◽

pp. 4231-4240 ◽

Cited By ~ 51

Author(s):

Jing Xu ◽

Melissa A. Kirigiti ◽

Kevin L. Grove ◽

M. Susan Smith

Keyword(s):

Energy Balance ◽

Food Intake ◽

Negative Energy ◽

Serum Glucose ◽

Negative Energy Balance ◽

Serum Lh ◽

Low Levels ◽

Agouti Related Protein ◽

Insulin Replacement

Abstract Negative energy balance during lactation is reflected by low levels of insulin and leptin and is associated with chronic hyperphagia and suppressed GnRH/LH activity. We studied whether restoration of insulin and/or leptin to physiological levels would reverse the lactation-associated hyperphagia, changes in hypothalamic neuropeptide expression [increased neuropeptide Y (NPY) and agouti-related protein (AGRP) and decreased proopiomelanocortin (POMC), kisspeptin (Kiss1), and neurokinin B (NKB)] and suppression of LH. Ovariectomized lactating rats (eight pups) were treated for 48 h with sc minipumps containing saline, human insulin, or rat leptin. The arcuate nucleus (ARH) was analyzed for NPY, AGRP, POMC, Kiss1, and NKB mRNA expression; the dorsal medial hypothalamus (DMH) was analyzed for NPY mRNA. Insulin replacement reversed the increase in ARH NPY/AGRP mRNAs, partially recovered POMC, but had no effect on recovering Kiss1/NKB. Leptin replacement only affected POMC, which was fully recovered. Insulin/leptin dual replacement had similar effects as insulin replacement alone but with a slight increase in Kiss1/NKB. The lactation-induced increase in DMH NPY was unchanged after treatments. Restoration of insulin and/or leptin had no effect on food intake, body weight, serum glucose or serum LH. These results suggest that the negative energy balance of lactation is not required for the hyperphagic drive, although it is involved in the orexigenic changes in the ARH. The chronic hyperphagia of lactation is most likely sustained by the induction of NPY in the DMH. The negative energy balance also does not appear to be a necessary prerequisite for the suppression of GnRH/LH activity.

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Supplementing an energy adequate, higher protein diet with protein does not enhance fat-free mass restoration after short-term severe negative energy balance

Journal of Applied Physiology ◽

10.1152/japplphysiol.01039.2016 ◽

2017 ◽

Vol 122 (6) ◽

pp. 1485-1493 ◽

Cited By ~ 12

Author(s):

C. E. Berryman ◽

J. J. Sepowitz ◽

H. L. McClung ◽

H. R. Lieberman ◽

E. K. Farina ◽

...

Keyword(s):

Energy Balance ◽

G Protein ◽

Military Training ◽

Negative Energy ◽

Fat Free Mass ◽

Negative Energy Balance ◽

Short Term ◽

Protein Balance ◽

Ad Libitum ◽

Net Protein

Negative energy balance during military operations can be severe and result in significant reductions in fat-free mass (FFM). Consuming supplemental high-quality protein following such military operations may accelerate restoration of FFM. Body composition (dual-energy X-ray absorptiometry) and whole body protein turnover (single-pool [15N]alanine method) were determined before (PRE) and after 7 days (POST) of severe negative energy balance during military training in 63 male US Marines (means ± SD, 25 ± 3 yr, 84 ± 9 kg). After POST measures were collected, volunteers were randomized to receive higher protein (HIGH: 1,103 kcal/day, 133 g protein/day), moderate protein (MOD: 974 kcal/day, 84 g protein/day), or carbohydrate-based low protein control (CON: 1,042 kcal/day, 7 g protein/day) supplements, in addition to a self-selected, ad libitum diet, for the 27-day intervention (REFED). Measurements were repeated POST-REFED. POST total body mass (TBM; −5.8 ± 1.0 kg, −7.0%), FFM (−3.1 ± 1.6 kg, −4.7%), and net protein balance (−1.7 ± 1.1 g protein·kg−1·day−1) were lower and proteolysis (1.1 ± 1.9 g protein·kg−1·day−1) was higher compared with PRE ( P < 0.05). Self-selected, ad libitum dietary intake during REFED was similar between groups (3,507 ± 730 kcal/day, 2.0 ± 0.5 g protein·kg−1·day−1). However, diets differed by protein intake due to supplementation (CON: 2.0 ± 0.4, MOD: 3.2 ± 0.7, and HIGH: 3.5 ± 0.7 g·kg−1·day−1; P < 0.05) but not total energy (4,498 ± 725 kcal/day). All volunteers, independent of group assignment, achieved positive net protein balance (0.4 ± 1.0 g protein·kg−1·day−1) and gained TBM (5.9 ± 1.7 kg, 7.8%) and FFM (3.6 ± 1.8 kg, 5.7%) POST-REFED compared with POST ( P < 0.05). Supplementing ad libitum, energy-adequate, higher protein diets with additional protein may not be necessary to restore FFM after short-term severe negative energy balance. NEW & NOTEWORTHY This article demonstrates 1) the majority of physiological decrements incurred during military training (e.g., total and fat-free mass loss), with the exception of net protein balance, resolve and return to pretraining values after 27 days and 2) protein supplementation, in addition to an ad libitum, higher protein (~2.0 g·kg−1·day−1), energy adequate diet, is not necessary to restore fat-free mass following short-term severe negative energy balance.

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Adaptation to Positive and Negative Energy Balance in Humans: The Role of the Genotype

Obesity: Dietary Factors and Control ◽

10.1159/000420929 ◽

2015 ◽

pp. 201-213

Author(s):

Claude Bouchard

Keyword(s):

Energy Balance ◽

Negative Energy ◽

Negative Energy Balance

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Energy Balance Indicators during the Transition Period and Early Lactation of Purebred Holstein and Simmental Cows and Their Crosses

Animals ◽

10.3390/ani11020309 ◽

2021 ◽

Vol 11 (2) ◽

pp. 309

Author(s):

Deise Aline Knob ◽

André Thaler Neto ◽

Helen Schweizer ◽

Anna C. Weigand ◽

Roberto Kappes ◽

...

Keyword(s):

Energy Balance ◽

Milk Yield ◽

Milk Composition ◽

Negative Energy ◽

The Other ◽

Negative Energy Balance ◽

Metabolic Energy ◽

Genetic Groups ◽

Significant Difference ◽

Fat Thickness

Crossbreeding in dairy cattle has been used to improve functional traits, milk composition, and efficiency of Holstein herds. The objective of the study was to compare indicators of the metabolic energy balance, nonesterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), glucose, body condition score (BCS) back fat thickness (BFT), as well as milk yield and milk composition of Holstein and Simmental cows, and their crosses from the prepartum period until the 100th day of lactation at the Livestock Center of the Ludwig Maximilians University (Munich, Germany). In total, 164 cows formed five genetic groups according to their theoretic proportion of Holstein and Simmental genes as follows: Holstein (100% Holstein; n = 9), R1-Hol (51–99% Holstein; n = 30), first generation (F1) crossbreds (50% Holstein, 50% Simmental; n = 17), R1-Sim (1–49% Holstein; n = 81) and Simmental (100% Simmental; n = 27). The study took place between April 2018 and August 2019. BCS, BFT blood parameters, such as BHBA, glucose, and NEFA were recorded weekly. A mixed model analysis with fixed effects breed, week (relative to calving), the interaction of breed and week, parity, calving year, calving season, milking season, and the repeated measure effect of cow was used. BCS increased with the Simmental proportion. All genetic groups lost BCS and BFT after calving. Simmental cows showed lower NEFA values. BHBA and glucose did not differ among genetic groups, but they differed depending on the week relative to calving. Simmental and R1-Sim cows showed a smaller effect than the other genetic groups regarding changes in body weight, BCS, or back fat thickness after a period of a negative energy balance after calving. There was no significant difference for milk yield among genetic groups, although Simmental cows showed a lower milk yield after the third week after calving. Generally, Simmental and R1-Simmental cows seemed to deal better with a negative energy balance after calving than purebred Holstein and the other crossbred lines. Based on a positive heterosis effect of 10.06% for energy corrected milk (ECM), the F1, however, was the most efficient crossbred line.

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Metabolic Adaptations to Dynamic Energy Requirements during Lactation and Pregnancy in Dairy Cows with Varying Proportions of Holstein and Simmental Breed

Proceedings ◽

10.3390/ieca2020-08833 ◽

2020 ◽

Vol 73 (1) ◽

pp. 9

Author(s):

Deise Aline Knob ◽

André Thaler Neto ◽

Helen Schweizer ◽

Anna Weigand ◽

Roberto Kappes ◽

...

Keyword(s):

Energy Balance ◽

Dairy Cows ◽

Fixed Effects ◽

Mixed Model ◽

Negative Energy ◽

Negative Energy Balance ◽

Repeated Measure ◽

Holstein Cows ◽

Mixed Model Analysis ◽

Genetic Groups

Depending on the breed or crossbreed line, cows have to cope with a more or less severe negative energy balance during the period of high milk yields in early lactation, which can be detected by beta-hydroxybutyrate (BHBA) and non-esterified fatty acids (NEFAs) in blood. Preventing cows from undergoing a severe negative energy balance by breeding and/or feeding measures is likely to be supported by the public and may help to improve the sustainability of milk production. The aim was to compare BHBA and NEFA concentrations in the blood of Holstein and Simmental cows and their crosses during the prepartum period until the end of lactation. In total, 164 cows formed five genetic groups according to their theoretic proportion of Holstein and Simmental genes as follows: Holstein (100% Holstein; n = 9), R1-Hol (51–99% Holstein; n = 30), F1 crossbreds (50% Holstein, 50% Simmental; n = 17), R1-Sim (1–49% Holstein; n = 81) and Simmental (100% Simmental; n = 27). NEFA and BHBA were evaluated once a week between April 2018 and August 2019. A mixed model analysis with fixed effects breed, week (relative to calving), the interaction of breed and week, parity, calving year, calving season, milking season, and the repeated measure effect on cows was used. Holstein cows had higher NEFAs (0.196 ± 0.013 mmol/L), and Simmental cows had the lowest NEFA concentrations (0.147 ± 0.008 mmol/L, p = 0.03). R1-Sim, F1 and R1-Hol cows had intermediate values (0.166 ± 0.005, 0.165 ± 0.010, 0.162 ± 0.008 mmol/L; respectively). The highest NEFA value was found in the first week after calving (0.49 ± 0.013 mmol/L). BHBA did not differ among genetic groups (p = 0.1007). There was, however, an interaction between the genetic group and week (p = 0.03). While Simmental, R1-Sim and F1 cows had the highest BHBA value, the second week after calving (0.92 ± 0.07 and 1.05 ± 0.04, and 1.10 ± 0.10 mmol/L, respectively), R1-Hol and Holstein cows showed the BHBA peak at the fourth week after calving (1.16 ± 0.07 and 1.36 ± 0.12 mmol/L, respectively). Unexpectedly, Holstein cows had a high BHBA peak again at week 34 after calving (1.68 ± 0.21 mmol/L). The genetic composition of the cows affects NEFA and BHBA. Simmental and R1-Sim cows mobilize fewer body reserves after calving. Therefore, dairy cows with higher degrees of Simmental origin might be more sustainable in comparison with Holstein genetics in the present study.

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The Capacity of Holstein-Friesian and Simmental Cows to Correct a Negative Energy Balance in Relation to Their Performance Parameters, Course of Lactation, and Selected Milk Components

Animals ◽

10.3390/ani11061674 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1674

Author(s):

Ilona Strączek ◽

Krzysztof Młynek ◽

Agata Danielewicz

Keyword(s):

Fatty Acid ◽

Energy Balance ◽

Dairy Cows ◽

Body Condition ◽

Body Condition Score ◽

Negative Energy ◽

Negative Energy Balance ◽

Holstein Friesian ◽

Condition Score ◽

Peak Lactation

A significant factor in improving the performance of dairy cows is their physiological ability to correct a negative energy balance (NEB). This study, using Simmental (SIM) and Holstein-Friesian (HF) cows, aimed to assess changes in NEB (non-esterified fatty acid; body condition score; and C16:0, C18:0, and C18:1) and its effect on the metabolic efficiency of the liver (β-hydroxybutyrate and urea). The effects of NEB on daily yield, production at peak lactation and its duration, and changes in selected milk components were assessed during complete lactation. Up to peak lactation, the loss of the body condition score was similar in both breeds. Subsequently, SIM cows more efficiently restored their BCS. HF cows reached peak lactation faster and with a higher milk yield, but they were less able to correct NEB. During lactation, their non-esterified fatty acid, β-hydroxybutyrate, C16:0, C18:0, C18:1, and urea levels were persistently higher, which may indicate less efficient liver function during NEB. The dynamics of NEB were linked to levels of leptin, which has anorectic effects. Its content was usually higher in HF cows and during intensive lactogenesis. An effective response to NEB may be exploited to improve the production and nutritional properties of milk. In the long term, it may extend dairy cows’ productive life and increase lifetime yield.

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