Energy expenditure and balance during spaceflight on the space shuttle

1999 ◽  
Vol 276 (6) ◽  
pp. R1739-R1748 ◽  
Author(s):  
T. P. Stein ◽  
M. J. Leskiw ◽  
M. D. Schluter ◽  
R. W. Hoyt ◽  
H. W. Lane ◽  
...  

The objectives of this study were as follows: 1) to measure human energy expenditure (EE) during spaceflight on a shuttle mission by using the doubly labeled water (DLW) method; 2) to determine whether the astronauts were in negative energy balance during spaceflight; 3) to use the comparison of change in body fat as measured by the intake DLW EE,18O dilution, and dual energy X-ray absorptiometry (DEXA) to validate the DLW method for spaceflight; and 4) to compare EE during spaceflight against that found with bed rest. Two experiments were conducted: a flight experiment ( n = 4) on the 16-day 1996 life and microgravity sciences shuttle mission and a 6° head-down tilt bed rest study with controlled dietary intake ( n = 8). The bed rest study was designed to simulate the flight experiment and included exercise. Two EE determinations were done before flight (bed rest), during flight (bed rest), and after flight (recovery). Energy intake and N balance were monitored for the entire period. Results were that body weight, water, fat, and energy balance were unchanged with bed rest. For the flight experiment, decreases in weight (2.6 ± 0.4 kg, P < 0.05) and N retention (−2.37 ± 0.45 g N/day, P < 0.05) were found. Dietary intake for the four astronauts was reduced in flight (3,025 ± 180 vs. 1,943 ± 179 kcal/day, P < 0.05). EE in flight was 3,320 ± 155 kcal/day, resulting in a negative energy balance of 1,355 ± 80 kcal/day (−15.7 ± 1.0 kcal ⋅ kg−1 ⋅ day−1, P < 0.05). This corresponded to a loss of 2.1 ± 0.4 kg body fat, which was within experimental error of the fat loss determined by18O dilution (−1.4 ± 0.5 kg) and DEXA (−2.4 ± 0.4 kg). All three methods showed no change in body fat with bed rest. In conclusion, 1) the DLW method for measuring EE during spaceflight is valid, 2) the astronauts were in severe negative energy balance and oxidized body fat, and 3) in-flight energy (E) requirements can be predicted from the equation: E = 1.40 × resting metabolic rate + exercise.

2021 ◽  
Author(s):  
Patrick Mullie ◽  
Pieter Maes ◽  
Laurens van Veelen ◽  
Damien Van Tiggelen ◽  
Peter Clarys

ABSTRACT Introduction Adequate energy supply is a prerequisite for optimal performances and recovery. The aims of the present study were to estimate energy balance and energy availability during a selection course for Belgian paratroopers. Methods Energy expenditure by physical activity was measured with accelerometer (ActiGraph GT3X+, ActiGraph LLC, Pensacola, FL, USA) and rest metabolic rate in Cal.d−1 with Tinsley et al.’s equation based on fat-free mass = 25.9 × fat-free mass in kg + 284. Participants had only access to the French individual combat rations of 3,600 Cal.d−1, and body fat mass was measured with quadripolar impedance (Omron BF508, Omron, Osaka, Japan). Energy availability was calculated by the formula: ([energy intake in foods and beverages] − [energy expenditure physical activity])/kg FFM−1.d−1, with FFM = fat-free mass. Results Mean (SD) age of the 35 participants was 25.1 (4.18) years, and mean (SD) percentage fat mass was 12.0% (3.82). Mean (SD) total energy expenditure, i.e., the sum of rest metabolic rate, dietary-induced thermogenesis, and physical activity, was 5,262 Cal.d−1 (621.2), with percentile 25 at 4,791 Cal.d−1 and percentile 75 at 5,647 Cal.d−1, a difference of 856 Cal.d−1. Mean daily energy intake was 3,600 Cal.d−1, giving a negative energy balance of 1,662 (621.2) Cal.d−1. Mean energy availability was 9.3 Cal.kg FFM−1.d−1. Eleven of the 35 participants performed with a negative energy balance of 2,000 Cal.d−1, and only five participants out of 35 participants performed at a less than 1,000 Cal.d−1 negative energy balance level. Conclusions Energy intake is not optimal as indicated by the negative energy balance and the low energy availability, which means that the participants to this selection course had to perform in suboptimal conditions.


Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3394
Author(s):  
Sarah A. Purcell ◽  
Ryan J. Marker ◽  
Marc-Andre Cornier ◽  
Edward L. Melanson

Many breast cancer survivors (BCS) gain fat mass and lose fat-free mass during treatment (chemotherapy, radiation, surgery) and estrogen suppression therapy, which increases the risk of developing comorbidities. Whether these body composition alterations are a result of changes in dietary intake, energy expenditure, or both is unclear. Thus, we reviewed studies that have measured components of energy balance in BCS who have completed treatment. Longitudinal studies suggest that BCS reduce self-reported energy intake and increase fruit and vegetable consumption. Although some evidence suggests that resting metabolic rate is higher in BCS than in age-matched controls, no study has measured total daily energy expenditure (TDEE) in this population. Whether physical activity levels are altered in BCS is unclear, but evidence suggests that light-intensity physical activity is lower in BCS compared to age-matched controls. We also discuss the mechanisms through which estrogen suppression may impact energy balance and develop a theoretical framework of dietary intake and TDEE interactions in BCS. Preclinical and human experimental studies indicate that estrogen suppression likely elicits increased energy intake and decreased TDEE, although this has not been systematically investigated in BCS specifically. Estrogen suppression may modulate energy balance via alterations in appetite, fat-free mass, resting metabolic rate, and physical activity. There are several potential areas for future mechanistic energetic research in BCS (e.g., characterizing predictors of intervention response, appetite, dynamic changes in energy balance, and differences in cancer sub-types) that would ultimately support the development of more targeted and personalized behavioral interventions.


1998 ◽  
Vol 10 (1) ◽  
pp. 65 ◽  
Author(s):  
Stephen J. Judd

Animal reproduction is impaired when intake of energy is so restricted that activities essential to life are threatened; this is seen as a homeostatic adjustment that restricts wasteful energy expenditure. Fasting or exercising to a degree requiring considerable energy expenditure has major effects on the hypothalamus, including activation of corticotrophin-releasing factor (CRF) neurons, suppression of thyrotrophin-releasing hormone synthesis, and increased growth hormone secretion; these are associated with increased concentrations of hypothalamic neuropeptide Y mRNA and are corrected by administration of leptin, an adipose-tissue protein with a tertiary structure similar to the cytokine interleukin-2. This response to fasting results from a disordered pattern of activity in the gonadotrophin-releasing hormone (GnRH) pacemaker, characterized by reduced luteinizing hormone pulsatility, particularly during daytime. Animal studies have suggested that the response depends on an intact afferent vagal system from the stomach and the presence of oestrogen. Noradrenergic neurons forming the A2 group increase the activity of CRF neurons that, in turn, inhibit GnRH pulsatility. Reproductive impairment due to fasting is reversed by leptin, and abnormalities of leptin are described in individuals who fast or who develop exercise-induced amenorrhoea. This paper discusses these changes induced by negative energy balance and speculates on the involvement of leptin as a contributor to these abnormalities.


2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0020
Author(s):  
Julie A. Young ◽  
Jessica Napolitano ◽  
Mitchell J. Rauh ◽  
Jeanne Nichols ◽  
Anastasia N. Fischer

BACKGROUND: Prior studies have shown that vital signs such as heart rate, blood pressure and body temperature are depressed in patients with an eating disorder who have experienced a negative energy balance for a significant amount of time. More recently, a negative energy balance has been the focus of Relative Energy Deficiency in Sport (RED-S), which links energy availability to the health of multiple body systems in adults in as little as 5 days with a negative energy balance. High rates of disordered eating patterns have been reported in high school athletes. As adolescents grow, the consequences of a negative energy balance can be significant and potentially irreversible. Thus, vital signs may help clinicians quickly evaluate a patient’s energy status or highlight them for further evaluation. PURPOSE: The purpose of this study was to examine energy balance and vital signs in a cohort of adolescents who were seen by a sports dietitian to gain weight or optimize sports performance. METHODS: We evaluated 240 subjects, 83% female, average age 15.0±2.3 years. Heart rate and blood pressure were measured with a dynamometer in a seated position. Body temperature was measured orally. Height and weight were recorded. BMI was then calculated and evaluated by percentile. Energy intake was assessed using a 3-day food recall log. Energy expenditure was calculated using Harris Benedict Equation and combined with estimated exercise energy expenditure. Energy balance was estimated as energy intake minus energy expenditure. RESULTS: Average age was 15.03±2.71. 85% were female. 30% were below the 15th percentile for BMI. There were no differences in BMI percentiles between males and females (p=0.99). The average heart rate was 71.62±13.4 bpm and 19% were below the 10th percentile for heart rate. Average systolic blood pressure was 110±11 mm Hg and average diastolic blood pressure was 62±7 mmHg. Average temperature was 98.1±.4 degrees F. 88%were in a negative energy balance with an average energy deficit of 552±511 calories. There were no statistically significant differences in energy balance between males and females (p=0.08). CONCLUSIONS: A disproportional number of children with low BMI and heart rate percentiles was observed, which may indicate a long-standing energy deficiency. We also found a high proportion of adolescents who experienced a standalone negative energy balance itself or vital signs consistent with a negative energy balance. Additional studies are needed to study the relationships between energy deficit magnitude and duration in adolescents and children.


Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 470 ◽  
Author(s):  
Hannah Zabriskie ◽  
Bradley Currier ◽  
Patrick Harty ◽  
Richard Stecker ◽  
Andrew Jagim ◽  
...  

Little data is available regarding the energy and nutritional status of female collegiate team sport athletes. Twenty female NCAA Division II lacrosse athletes (mean ± SD: 20.4 ± 1.8 years; 68.8 ± 8.9 kg; 168.4 ± 6.6 cm; 27.9 ± 3% body fat) recorded dietary intake and wore a physical activity monitor over four consecutive days at five different time points (20 days total) during one academic year. Body composition, bone health, and resting metabolic rate were assessed in conjunction with wearing the monitor during off-season, pre-season, and season-play. Body fat percentage decreased slightly during the course of this study (p = 0.037). Total daily energy expenditure (TDEE) (p < 0.001) and activity energy expenditure (AEE) (p = 0.001) energy were found to change significantly over the course of the year, with pre-season training resulting in the highest energy expenditures (TDEE: 2789 ± 391 kcal/day; AEE: 1001 ± 267 kcal/day). Caloric (2124 ± 448 kcal/day), carbohydrate (3.6 ± 1.1 g/kg), and protein (1.2 ± 0.3 g/kg) intake did not change over the course of the year (p > 0.05). Athletes self-reported a moderate negative energy balance (366–719 kcal/day) and low energy availability (22.9–30.4 kcal/kg FFM) at each measurement period throughout the study. Reported caloric and macronutrient intake was low given the recorded energy expenditure and macronutrient intake recommendations for athletes. Athletic support staff should provide athletes with appropriate fueling strategies, particularly during pre-season training, to adequately meet energy demands.


PLoS ONE ◽  
2013 ◽  
Vol 8 (7) ◽  
pp. e67786 ◽  
Author(s):  
Pilou L. H. R. Janssens ◽  
Rick Hursel ◽  
Eveline A. P. Martens ◽  
Margriet S. Westerterp-Plantenga

1995 ◽  
Vol 73 (2) ◽  
pp. 323-334 ◽  
Author(s):  
K. Klipstein-Grobusch ◽  
J. J. Reilly ◽  
J. Potter ◽  
C. A. Edwards ◽  
M. A. Roberts

Studies on hospitalized elderly subjects have demonstrated that negative energy balance is common during hospitalization, but have concentrated primarily on long-stay and psychogeriatric patients. There is little information on energy balance in elderly patients admitted with acute illness from the community, despite the importance of this patient group and the presence of a number of factors likely to predispose such patients to negative energy balance. In the present study energy balance was quantified in twenty patients (eight males, mean age 82 (SD 05) years; twelve females, mean age 84 (SD 6) years) admitted from the community with acute illness, and predicted basal metabolic rate (BMR) was compared with measured resting metabolic rate (RMR). Most patients were in negative energy balance during hospitalization, and median measured energy intake (El):measured RMR ratio was 1·0 (range 0·7–1·8). The mean difference between measured El and estimated total energy expenditure was −1·3 MJ/d (range -3·4 to +2·5 MJ/d). Estimated total energy expenditure exceeded measured El in fifteen of the patients and there was a significant decline in mid-arm muscle circumference (paired t, P < 0·05) during hospitalization. We conclude that moderate negative energy balance is common in this patient group, and that these patients are at risk of undernutrition during their hospital stay.


2021 ◽  
Vol 22 (10) ◽  
pp. 5365
Author(s):  
Antonio J. López-Gambero ◽  
Cristina Rosell-Valle ◽  
Dina Medina-Vera ◽  
Juan Antonio Navarro ◽  
Antonio Vargas ◽  
...  

Increasing evidence links metabolic disorders with neurodegenerative processes including Alzheimer’s disease (AD). Late AD is associated with amyloid (Aβ) plaque accumulation, neuroinflammation, and central insulin resistance. Here, a humanized AD model, the 5xFAD mouse model, was used to further explore food intake, energy expenditure, neuroinflammation, and neuroendocrine signaling in the hypothalamus. Experiments were performed on 6-month-old male and female full transgenic (Tg5xFAD/5xFAD), heterozygous (Tg5xFAD/-), and non-transgenic (Non-Tg) littermates. Although histological analysis showed absence of Aβ plaques in the hypothalamus of 5xFAD mice, this brain region displayed increased protein levels of GFAP and IBA1 in both Tg5xFAD/- and Tg5xFAD/5xFAD mice and increased expression of IL-1β in Tg5xFAD/5xFAD mice, suggesting neuroinflammation. This condition was accompanied by decreased body weight, food intake, and energy expenditure in both Tg5xFAD/- and Tg5xFAD/5xFAD mice. Negative energy balance was associated with altered circulating levels of insulin, GLP-1, GIP, ghrelin, and resistin; decreased insulin and leptin hypothalamic signaling; dysregulation in main metabolic sensors (phosphorylated IRS1, STAT5, AMPK, mTOR, ERK2); and neuropeptides controlling energy balance (NPY, AgRP, orexin, MCH). These results suggest that glial activation and metabolic dysfunctions in the hypothalamus of a mouse model of AD likely result in negative energy balance, which may contribute to AD pathogenesis development.


2018 ◽  
Vol 107 (4) ◽  
pp. 340-354 ◽  
Author(s):  
Rose Crossin ◽  
Zane B. Andrews ◽  
Natalie A. Sims ◽  
Terence Pang ◽  
Michael Mathai ◽  
...  

Background/Aims: Abuse of toluene products (e.g., glue-sniffing) primarily occurs during adolescence and has been associated with appetite suppression and weight impairments. However, the metabolic phenotype arising from adolescent inhalant abuse has never been fully characterised, and its persistence during abstinence and underlying mechanisms remain unknown. Methods: Adolescent male Wistar rats (post-natal day 27) were exposed to inhaled toluene (10,000 ppm) (n = 32) or air (n = 48) for 1 h/day, 3 days/week for 4 weeks, followed by 4 weeks of abstinence. Twenty air rats were pair-fed to the toluene group, to differentiate the direct effects of toluene from under-nutrition. Food intake, weight, and growth were monitored. Metabolic hormones were measured after exposure and abstinence periods. Energy expenditure was measured using indirect calorimetry. Adrenal function was assessed using adrenal histology and hormone testing. Results: Inhalant abuse suppressed appetite and increased energy expenditure. Reduced weight gain and growth were observed in both the toluene and pair-fed groups. Compared to the pair-fed group, and despite normalisation of food intake, the suppression of weight and growth for toluene-exposed rats persisted during abstinence. After exposure, toluene-exposed rats had low fasting blood glucose and insulin compared to the air and pair-fed groups. Consistent with adrenal insufficiency, adrenal hypertrophy and increased basal adrenocorticotropic hormone were observed in the toluene-exposed rats, despite normal basal corticosterone levels. Conclusions: Inhalant abuse results in negative energy balance, persistent growth impairment, and endocrine changes suggestive of adrenal insufficiency. We conclude that adrenal insufficiency contributes to the negative energy balance phenotype, potentially presenting a significant additional health risk for inhalant users.


2018 ◽  
Vol 315 (5) ◽  
pp. G685-G698 ◽  
Author(s):  
Ilya R. Bederman ◽  
Gavriella Pora ◽  
Maureen O’Reilly ◽  
James Poleman ◽  
Kimberly Spoonhower ◽  
...  

Negative energy balance is a prevalent feature of cystic fibrosis (CF). Pancreatic insufficiency, elevated energy expenditure, lung disease, and malnutrition, all characteristic of CF, contribute to the negative energy balance causing low body-growth phenotype. As low body weight and body mass index strongly correlate with poor lung health and survival of patients with CF, improving energy balance is an important clinical goal (e.g., high-fat diet). CF mouse models also exhibit negative energy balance (growth retardation and high energy expenditure), independent from exocrine pancreatic insufficiency, lung disease, and malnutrition. To improve energy balance through increased caloric intake and reduced energy expenditure, we disrupted leptin signaling by crossing the db/db leptin receptor allele with mice carrying the R117H Cftr mutation. Compared with db/db mice, absence of leptin signaling in CF mice (CF db/db) resulted in delayed and moderate hyperphagia with lower de novo lipogenesis and lipid deposition, producing only moderately obese CF mice. Greater body length was found in db/db mice but not in CF db/db, suggesting CF-dependent effect on bone growth. The db/db genotype resulted in lower energy expenditure regardless of Cftr genotype leading to obesity. Despite the db/db genotype, the CF genotype exhibited high respiratory quotient indicating elevated carbohydrate oxidation, thus limiting carbohydrates for lipogenesis. In summary, db/db-linked hyperphagia, elevated lipogenesis, and morbid obesity were partially suppressed by reduced CFTR activity. CF mice still accrued large amounts of adipose tissue in contrast to mice fed a high-fat diet, thus highlighting the importance of dietary carbohydrates and not simply fat for energy balance in CF. NEW & NOTEWORTHY We show that cystic fibrosis (CF) mice are able to accrue fat under conditions of carbohydrate overfeeding, increased lipogenesis, and decreased energy expenditure, although length was unaffected. High-fat diet feeding failed to improve growth in CF mice. Morbid db/db-like obesity was reduced in CF double-mutant mice by reduced CFTR activity.


Sign in / Sign up

Export Citation Format

Share Document