Loss of body fat during an arctic winter expedition

1977 ◽  
Vol 55 (6) ◽  
pp. 1235-1241 ◽  
Author(s):  
W. J. O'Hara ◽  
C. Allen ◽  
R. J. Shephard
Keyword(s):  
Weight Loss ◽  
Energy Balance ◽  
Body Fat ◽  
Lean Mass ◽  
Muscle Force ◽  
Aerobic Power ◽  
Canadian Arctic ◽  
Lean Tissue ◽  
Energy Expenditures ◽  
Daily Energy

Fifty-five soldiers have been observed over a vigorous 10-day sledging patrol in the Canadian arctic and subarctic. Initial observations showed a low level of physical fitness (26% body fat, aerobic power 41.9 ± 7.8 ml kg−1 min−1, handgrip force 43.7 ± 7.2 kg). Over the 2-week northern sojourn, energy expenditures as measured by a Kofranyi–Michaelis respirometer and diary observation averaged 3248 kcal (13.6 MJ) day−1, with a small (152 kcal (633 kJ)) positive daily energy balance. A weight loss of 1 kg, presumably water, was made good within 1 week of return to the south. A fat loss of some 3.9 kg was probably attributable largely to the demands of lean tissue synthesis. The lean mass was increased by 3.9 kg over the trial, with parallel gains of muscle force and aerobic power. The rapid mobilization of depot fat led to marked ketonuria.

scholarly journals Protein utilization during energy undernutrition in sheep sustained by intragastric infusion: effects of protein infusion level, with or without sub-maintenance amounts of energy from volatile fatty acids, on energy and protein metabolism

1997 ◽  
Vol 77 (4) ◽  
pp. 565-576 ◽  
Author(s):  
S. A. Chowdhury ◽  
E. R. Ørskov ◽  
F. D. DeB. Hovell ◽  
J. R. Scaife ◽  
G. Mollison
Keyword(s):  
Fatty Acids ◽  
Energy Balance ◽  
Body Fat ◽  
Volatile Fatty Acids ◽  
Negative Energy ◽  
Tissue Growth ◽  
N Balance ◽  
Lean Tissue ◽  
Energy Needs ◽  
Daily Energy

Utilization of endogenous and exogenous energy for protein accretion during energy undernutrition has been studied. Nine lambs nourished by intragastric infusion were given either progressively increasing or decreasing amounts of casein-N up to 2550 mg/kg metabolic weight (W0·75), with or without 250 kJ/kg W0·75 of volatile fatty acids daily. Energy balance (respiration calorimetry) and N balance were measured. While all experimental animals were in negative energy balance, N balance increased curve-linearly with the increase in casein-N infusion and attained positive N balance. Endogenous energy (presumably body fat) was found to meet the energy needs for protein accretion during energy undernutrition. It is concluded that body fat can be effectively utilized to support lean-tissue growth during energy undernutrition, so that the classical nutritional concept of dietary energy:protein ratio is only meaningful when both endogenous and exogenous energy are considered.

Math for Real: Losing Weight versus Losing Fat

2009 ◽  
Vol 15 (3) ◽  
pp. 184-185
Keyword(s):  
Weight Loss ◽  
Body Composition ◽  
Body Fat ◽  
Exercise Program ◽  
The Body ◽  
Lean Tissue ◽  
Personal Trainer ◽  
Healthy Body

Measuring weight loss is important in determining if an exercise program works, but it is not the only objective. Losing body fat and maintaining a healthy body composition are more important. Body composition consists of lean tissue and fat. The body needs a certain amount of fat for essential functions (energy, regulating temperature). Karin Cottman, a certified personal trainer in Middleburg Heights, Ohio, keeps these ideas in mind when developing workout plans and diet goals for her clients.

scholarly journals A new method for measuring the body density of obese adults

1979 ◽  
Vol 42 (2) ◽  
pp. 173-183 ◽  
Author(s):  
J. S. Garrow ◽  
Susan Stalley ◽  
R. Diethelm ◽  
Ph. Pittet ◽  
R. Hesp ◽  
...  
Keyword(s):  
Weight Loss ◽  
Energy Balance ◽  
Body Fat ◽  
Total Body Water ◽  
Fat Content ◽  
Body Water ◽  
The Body ◽  
New Method ◽  
Obese Women ◽  
Total Body

1. A new apparatus is described with which it is possible to measure the volume (and hence density) of obese patients without requiring them to immerse totally in water. Replicate measurements of subjects with 6, 23 and 38 kg body fat had a standard deviation not greater than 0.3 kg fat.2. In nineteen obese women body fat was measured by density, total body water, and total body potassium at the beginning, and again at the end, of a period of 3–4 weeks on a reducing diet, during which they lost 5.43 (SD 1.83) kg in weight. The composition of weight loss was also estimated both by energy balance and nitrogen balance during the interval between the two measurements of body composition.3. The estimates of fat content of the nineteen women at the start of the balance period were 45.63 (SD 14.50)kg by density, 48.07 (SD 13.88) kg by K and 47.09 (SD 13.85) kg by water. The correlation coefficient between the density and K estimate was 0–949, and for the density and water estimate it was 0.971.4. It is concluded that measurement of density by the new method provides a convenient method for estimating body fatness, and change in fat content, which compares favourably with estimates based on total body water or total body K. However, these methods cannot be used to provide an accurate estimate of the composition of a small weight loss in an individual since deviations up to 4 kg fat occur between fat loss based on change in density and those based on the more reliable (but more tedious) energy balance method.

scholarly journals The effect of intermittent energy and carbohydrate restrictionv. daily energy restriction on weight loss and metabolic disease risk markers in overweight women

2013 ◽  
Vol 110 (8) ◽  
pp. 1534-1547 ◽  
Author(s):  
Michelle Harvie ◽  
Claire Wright ◽  
Mary Pegington ◽  
Debbie McMullan ◽  
Ellen Mitchell ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Weight Loss ◽  
Insulin Sensitivity ◽  
Body Fat ◽  
Disease Risk ◽  
Phase 1 ◽  
Weight Maintenance ◽  
Energy Restriction ◽  
Overweight Women ◽  
Daily Energy

Intermittent energy restriction may result in greater improvements in insulin sensitivity and weight control than daily energy restriction (DER). We tested two intermittent energy and carbohydrate restriction (IECR) regimens, including one which allowedad libitumprotein and fat (IECR+PF). Overweight women (n115) aged 20 and 69 years with a family history of breast cancer were randomised to an overall 25 % energy restriction, either as an IECR (2500–2717 kJ/d, < 40 g carbohydrate/d for 2 d/week) or a 25 % DER (approximately 6000 kJ/d for 7 d/week) or an IECR+PF for a 3-month weight-loss period and 1 month of weight maintenance (IECR or IECR+PF for 1 d/week). Insulin resistance reduced with the IECR diets (mean − 0·34 (95 % CI − 0·66, − 0·02) units) and the IECR+PF diet (mean − 0·38 (95 % CI − 0·75, − 0·01) units). Reductions with the IECR diets were significantly greater compared with the DER diet (mean 0·2 (95 % CI − 0·19, 0·66) μU/unit,P= 0·02). Both IECR groups had greater reductions in body fat compared with the DER group (IECR: mean − 3·7 (95 % CI − 2·5, − 4·9) kg,P= 0·007; IECR+PF: mean − 3·7 (95 % CI − 2·8, − 4·7) kg,P= 0·019; DER: mean − 2·0 (95 % CI − 1·0, 3·0) kg). During the weight maintenance phase, 1 d of IECR or IECR+PF per week maintained the reductions in insulin resistance and weight. In the short term, IECR is superior to DER with respect to improved insulin sensitivity and body fat reduction. Longer-term studies into the safety and effectiveness of IECR diets are warranted.

scholarly journals Increasing Energy Flux to Maintain Diet-Induced Weight Loss

Nutrients ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2533 ◽  
Author(s):  
Christopher L. Melby ◽  
Hunter L. Paris ◽  
R. Drew Sayer ◽  
Christopher Bell ◽  
James O. Hill
Keyword(s):  
Physical Activity ◽  
Weight Loss ◽  
Body Weight ◽  
Energy Balance ◽  
Energy Expenditure ◽  
Energy Flux ◽  
Weight Maintenance ◽  
High Energy ◽  
Daily Energy

Long-term maintenance of weight loss requires sustained energy balance at the reduced body weight. This could be attained by coupling low total daily energy intake (TDEI) with low total daily energy expenditure (TDEE; low energy flux), or by pairing high TDEI with high TDEE (high energy flux). Within an environment characterized by high energy dense food and a lack of need for movement, it may be particularly difficult for weight-reduced individuals to maintain energy balance in a low flux state. Most of these individuals will increase body mass due to an inability to sustain the necessary level of food restriction. This increase in TDEI may lead to the re-establishment of high energy flux at or near the original body weight. We propose that following weight loss, increasing physical activity can effectively re-establish a state of high energy flux without significant weight regain. Although the effect of extremely high levels of physical activity on TDEE may be constrained by compensatory reductions in non-activity energy expenditure, moderate increases following weight loss may elevate energy flux and encourage physiological adaptations favorable to weight loss maintenance, including better appetite regulation. It may be time to recognize that few individuals are able to re-establish energy balance at a lower body weight without permanent increases in physical activity. Accordingly, there is an urgent need for more research to better understand the role of energy flux in long-term weight maintenance.

scholarly journals A randomized controlled trial to isolate the effects of fasting and energy restriction on weight loss and metabolic health in lean adults

2021 ◽  
Vol 13 (598) ◽  
pp. eabd8034
Author(s):  
Iain Templeman ◽  
Harry Alex Smith ◽  
Enhad Chowdhury ◽  
Yung-Chih Chen ◽  
Harriet Carroll ◽  
...  
Keyword(s):  
Randomized Controlled Trial ◽  
Energy Balance ◽  
Energy Intake ◽  
Body Mass ◽  
Body Fat ◽  
Fat Mass ◽  
Controlled Trial ◽  
Energy Restriction ◽  
Randomized Controlled ◽  
Daily Energy

Intermittent fasting may impart metabolic benefits independent of energy balance by initiating fasting-mediated mechanisms. This randomized controlled trial examined 24-hour fasting with 150% energy intake on alternate days for 3 weeks in lean, healthy individuals (0:150; n = 12). Control groups involved a matched degree of energy restriction applied continuously without fasting (75% energy intake daily; 75:75; n = 12) or a matched pattern of fasting without net energy restriction (200% energy intake on alternate days; 0:200; n = 12). Primary outcomes were body composition, components of energy balance, and postprandial metabolism. Daily energy restriction (75:75) reduced body mass (−1.91 ± 0.99 kilograms) almost entirely due to fat loss (−1.75 ± 0.79 kilograms). Restricting energy intake via fasting (0:150) also decreased body mass (−1.60 ± 1.06 kilograms; P = 0.46 versus 75:75) but with attenuated reductions in body fat (−0.74 ± 1.32 kilograms; P = 0.01 versus 75:75), whereas fasting without energy restriction (0:200) did not significantly reduce either body mass (−0.52 ± 1.09 kilograms; P ≤ 0.04 versus 75:75 and 0:150) or fat mass (−0.12 ± 0.68 kilograms; P ≤ 0.05 versus 75:75 and 0:150). Postprandial indices of cardiometabolic health and gut hormones, along with the expression of key genes in subcutaneous adipose tissue, were not statistically different between groups (P > 0.05). Alternate-day fasting less effectively reduces body fat mass than a matched degree of daily energy restriction and without evidence of fasting-specific effects on metabolic regulation or cardiovascular health.

Abstract P246: Lean Body Mass, Percent Body Fat, and HbA1c in the U.S. Population: The National Health and Nutrition Examination Survey (NHANES 1999-2006)

Circulation ◽  
2015 ◽  
Vol 131 (suppl_1) ◽  
Author(s):  
Julie K Bower ◽  
Rachel Brackett ◽  
Meredith C Foster ◽  
Randi E Foraker
Keyword(s):  
Weight Loss ◽  
Waist Circumference ◽  
Lean Body Mass ◽  
Body Mass ◽  
Body Fat ◽  
Lean Mass ◽  
Diabetes Prevention ◽  
Percent Body Fat ◽  
Race Ethnicity ◽  
Diagnosed Diabetes

Introduction: Weight loss is an important component of diabetes prevention and management because of the known effect of adiposity on insulin resistance. While both muscle (lean mass) and fat mass are known to serve important metabolic functions, most studies of obesity and diabetes use proxy measures for overall or abdominal obesity without accounting for the composition of that mass. The aim of this study was to examine the association of total and trunk lean body mass and fat mass with hemoglobin A1c (HbA1c) - an indicator of glucose control in persons with diabetes and a risk marker in non-diabetic populations - in the general U.S. population. Methods: We conducted a cross-sectional analysis of data from the NHANES collected in 1999-2006 in participants aged 18-69 years. Lean body mass and percent body fat were determined using dual energy x-ray absorptiometry (DXA); analyses were weighted and multiple imputation was applied to account for missing DXA data. Associations of body composition with HbA1C were evaluated using multiple linear regression. Results: The study sample included 1,085 participants with diagnosed diabetes (mean age 56 years, 50% male, mean HbA1c=7.6%) and 15,597 participants without diabetes (mean age 40 years, 51% women, mean HbA1c=5.3%). Trunk lean mass and total lean mass were significantly associated with lower HbA1c in adults without diabetes, independent of body mass index (BMI) and waist circumference. After adjustment for age, sex, race/ethnicity, and waist circumference, each 10 kg increase in trunk lean mass was associated with 0.07-% points lower HbA1c (95% CI: -0.09, -0.03). After adjustment for age, sex, race/ethnicity, and BMI, each 10kg increase in total lean mass was associated with 0.03-% points lower HbA1c (95% CI: -0.05, -0.0). Each 5% increase in trunk fat was associated with 0.5-% point higher HbA1c (95% CI: 0.45, 0.55) and each 5% increase in total fat was associated with 0.05-% point higher HbA1c (95% CI: 0.05, 0.06). Lean mass and percent body fat were not associated with HbA1c in participants with diagnosed diabetes (p > 0.05). Conclusions: Lean mass is independently associated with HbA1c in adults without diabetes. Interventions that target both weight loss where warranted and increasing lean mass via resistance training may have the most beneficial impact for diabetes prevention.

scholarly journals Intermittent Dieting: Theoretical Considerations for the Athlete

Sports ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 22 ◽  
Author(s):  
Jackson Peos ◽  
Layne Norton ◽  
Eric Helms ◽  
Andrew Galpin ◽  
Paul Fournier
Keyword(s):  
Weight Loss ◽  
Energy Balance ◽  
Body Fat ◽  
Traditional Approach ◽  
Energy Restriction ◽  
Adaptive Responses ◽  
Reduce Body Weight ◽  
Continuous Energy ◽  
Weight Loss Outcomes ◽  
Theoretical Considerations

Athletes utilise numerous strategies to reduce body weight or body fat prior to competition. The traditional approach requires continuous energy restriction (CER) for the entire weight loss phase (typically days to weeks). However, there is some suggestion that intermittent energy restriction (IER), which involves alternating periods of energy restriction with periods of greater energy intake (referred to as ‘refeeds’ or ‘diet breaks’) may result in superior weight loss outcomes than CER. This may be due to refeed periods causing transitory restoration of energy balance. Some studies indicate that intermittent periods of energy balance during energy restriction attenuate some of the adaptive responses that resist the continuation of weight and fat loss. While IER—like CER—is known to effectively reduce body fat in non-athletes, evidence for effectiveness of IER in athletic populations is lacking. This review provides theoretical considerations for successful body composition adjustment using IER, with discussion of how the limited existing evidence can be cautiously applied in athlete practice.

scholarly journals Trends in obesity and adiposity measures by race or ethnicity among adults in the United States 2011-18: population based study

BMJ ◽  
2021 ◽  
pp. n365
Author(s):  
Buyun Liu ◽  
Yang Du ◽  
Yuxiao Wu ◽  
Linda G Snetselaar ◽  
Robert B Wallace ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Waist Circumference ◽  
Ethnic Groups ◽  
Body Mass ◽  
Body Fat ◽  
Lean Mass ◽  
The United States ◽  
Population Based ◽  
Body Fat Percentage ◽  
Fat Percentage

AbstractObjectiveTo examine the trends in obesity and adiposity measures, including body mass index, waist circumference, body fat percentage, and lean mass, by race or ethnicity among adults in the United States from 2011 to 2018.DesignPopulation based study.SettingNational Health and Nutrition Examination Survey (NHANES), 2011-18.ParticipantsA nationally representative sample of US adults aged 20 years or older.Main outcome measuresWeight, height, and waist circumference among adults aged 20 years or older were measured by trained technicians using standardized protocols. Obesity was defined as body mass index of 30 or higher for non-Asians and 27.5 or higher for Asians. Abdominal obesity was defined as a waist circumference of 102 cm or larger for men and 88 cm or larger for women. Body fat percentage and lean mass were measured among adults aged 20-59 years by using dual energy x ray absorptiometry.ResultsThis study included 21 399 adults from NHANES 2011-18. Body mass index was measured for 21 093 adults, waist circumference for 20 080 adults, and body fat percentage for 10 864 adults. For the overall population, age adjusted prevalence of general obesity increased from 35.4% (95% confidence interval 32.5% to 38.3%) in 2011-12 to 43.4% (39.8% to 47.0%) in 2017-18 (P for trend<0.001), and age adjusted prevalence of abdominal obesity increased from 54.5% (51.2% to 57.8%) in 2011-12 to 59.1% (55.6% to 62.7%) in 2017-18 (P for trend=0.02). Age adjusted mean body mass index increased from 28.7 (28.2 to 29.1) in 2011-12 to 29.8 (29.2 to 30.4) in 2017-18 (P for trend=0.001), and age adjusted mean waist circumference increased from 98.4 cm (97.4 to 99.5 cm) in 2011-12 to 100.5 cm (98.9 to 102.1 cm) in 2017-18 (P for trend=0.01). Significant increases were observed in body mass index and waist circumference among the Hispanic, non-Hispanic white, and non-Hispanic Asian groups (all P for trend<0.05), but not for the non-Hispanic black group. For body fat percentage, a significant increase was observed among non-Hispanic Asians (30.6%, 29.8% to 31.4% in 2011-12; 32.7%, 32.0% to 33.4% in 2017-18; P for trend=0.001), but not among other racial or ethnic groups. The age adjusted mean lean mass decreased in the non-Hispanic black group and increased in the non-Hispanic Asian group, but no statistically significant changes were found in other racial or ethnic groups.ConclusionsAmong US adults, an increasing trend was found in obesity and adiposity measures from 2011 to 2018, although disparities exist among racial or ethnic groups.

Body Mass and Body Composition Changes over 7 Years in a Male Professional Rugby Union Team

2021 ◽  
Author(s):  
Clíodhna McHugh ◽  
Karen Hind ◽  
Aoife O'Halloran ◽  
Daniel Davey ◽  
Gareth Farrell ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Mass ◽  
Body Fat ◽  
Lean Mass ◽  
Total Mass ◽  
Rugby Union ◽  
Body Fat Percentage ◽  
Fat Percentage ◽  
Dxa Scans ◽  
Composition Changes

AbstractThe purpose of this study was to investigate longitudinal body mass and body composition changes in one professional rugby union team (n=123), (i) according to position [forwards (n=58) versus backs (n=65)], analysis of players with 6 consecutive seasons of DXA scans (n=21) and, (iii) to examine differences by playing status [academy and international], over 7 years. Players [mean age: 26.8 y, body mass index: 28.9+kg.m2] received DXA scans at fourtime points within each year. A modest (but non-significant) increase in mean total mass (0.8 kg) for professional players was reflected by increased lean mass and reduced body fat mass. At all-time points, forwards had a significantly greater total mass, lean mass and body fat percentage compared to backs (p<0.05). Academy players demonstrated increased total and lean mass and decreased body fat percentage over the first 3 years of senior rugby, although this was not significant. Senior and academy international players had greater lean mass and lower body fat percentage (p<0.05) than non-international counterparts. Despite modest increases in total mass; reflected by increased lean mass and reduced fat mass, no significant changes in body mass or body composition, irrespective of playing position were apparent over 7 years.

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