Following 2 diet-restricted male outdoor rock climbers: impact on oxidative stress and improvements in markers of cardiovascular risk

2008 ◽  
Vol 33 (6) ◽  
pp. 1250-1256 ◽  
Author(s):  
Krystal J. Merrells ◽  
James K. Friel ◽  
Maria Knaus ◽  
Miyoung Suh

Lower body fat percentage is positively associated with climbing performance. This may lead climbers to practice unhealthy diet restriction when no sport-specific nutrition information exists. This study examined whether prolonged diet restriction affects body composition, oxidative stress, or other potential health risks in outdoor rock climbers. Two healthy male climbers conducted a 5 week rock climbing trip with a limited food budget ($1 each per day). Subjects underwent an energy restriction of approximately 40%. Loss of body weight and fat mass at week 5 were 5.8% and 16.1%, respectively, and were accompanied by significant subcutaneous fat loss in the iliac crest and abdomen. Triacylglycerols (TG), free fatty acids and C-reactive protein (CRP) dramatically decreased from baseline to week 2, and then maintained the lower level until week 5. Plasma vitamin C was below the normal range, and F2-isoprostanes, a marker of oxidative stress, continuously increased to week 5. Superoxide dismutase and glutathione peroxidase increased to week 2, but had returned to baseline levels at week 5. These results indicate that prolonged reduced energy intake while climbing may have an impact on weight loss and fat mass loss, which may contribute to low circulating TG and CRP, indicating improvements in markers of cardiovascular risk, and may lead to increased oxidative stress and reduced circulating antioxidants. Further studies are warranted to determine whether antioxidant supplementation or increased energy intake reduce oxidative stress.

Author(s):  
Shai Olansky ◽  
Kayleigh M. Beaudry ◽  
Stacey Woods ◽  
Erin Barbour-Tuck ◽  
Kimberley L. Gammage ◽  
...  

Purpose: The transition to university is often accompanied by the adoption of negative lifestyle habits, which may result in weight and fat gain. While this has been demonstrated during 1st year, little is known about subsequent years. We investigated changes in body composition, energy expenditure, and dietary/energy intake from 1st to 4th year university. Methods: Thirty-eight students (14 males, 24 females) completed a lifestyle questionnaire and had their body mass, fat mass, lean body mass (LBM), and body fat percentage (%BF) measured three times: at the beginning and end of 1st year, and end of 4th year. Results: During 1st year, body mass, fat mass, LBM, and %BF increased (+3.2 ± 3.8 kg, +2.5 ± 3.0 kg, +0.7 ± 2.1 kg, +2.3 ± 4.9%, respectively; p < 0.01), while daily energy intake and expenditure decreased (−359 ± 1019 kcal·d−1 and −434 ± 786 kcal·d−1, respectively; p < 0.01). Between the end of 1st year and end of 4th year, body mass, LBM, and energy expenditure increased (+3.2 ± 3.8 kg, +1.3 ± 2.9 kg, +209 ± 703 kcal·d−1, respectively; p ≤ 0.05), while %BF, fat mass, and energy intake did not change. Conclusions: Although %BF and fat mass remained stable from the end of 1st year to the end of 4th year in this group of university students, the positive increase in energy expenditure was not enough to reverse the weight and fat gained during 1st year.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247292
Author(s):  
Jackson J. Peos ◽  
Eric R. Helms ◽  
Paul A. Fournier ◽  
James Krieger ◽  
Amanda Sainsbury

Athletes undergoing energy restriction for weight/fat reduction sometimes apply ‘diet breaks’ involving increased energy intake, but there is little empirical evidence of effects on outcomes. Twenty-six resistance-trained athletes (11/26 or 42% female) who had completed 12 weeks of intermittent energy restriction participated in this study. Participants had a mean (SD) age of 29.3 (6.4) years, a weight of 72.7 (15.9) kg, and a body fat percentage of 21.3 (7.5) %. During the 1-week diet break, energy intake was increased (by means of increased carbohydrate intake) to predicted weight maintenance requirements. While the 1-week diet break had no significant effect on fat mass, it led to small but significant increases in mean body weight (0.6 kg, P<0.001), fat-free mass (0.7 kg, P<0.001) and in resting energy expenditure, from a mean (and 95% confidence interval) of 7000 (6420 to 7580) kJ/day to 7200 (6620 to 7780) kJ/day (P = 0.026). Overall, muscle endurance in the legs (but not arms) improved after the diet break, including significant increases in the work completed by the quadriceps and hamstrings in a maximum-effort 25-repetition set, with values increasing from 2530 (2170 to 2890) J to 2660 (2310 to 3010) J (P = 0.018) and from 1280 (1130 to 1430) J to 1380 (1220 to 1540) J (P = 0.018) following the diet break, respectively. However, muscle strength did not change. Participants reported significantly lower sensations of hunger (P = 0.017), prospective consumption (P = 0.020) and irritability (P = 0.041) after the diet break, and significantly higher sensations of fullness (P = 0.002), satisfaction (P = 0.002), and alertness (P = 0.003). In summary, a 1-week diet break improved muscle endurance in the legs and increased mental alertness, and reduced appetite and irritability. With this considered, it may be wise for athletes to coordinate diet breaks with training sessions that require muscle endurance of the legs and/or mental focus, as well as in the latter parts of a weight loss phase when increases in appetite might threaten dietary adherence. Trial registration: Australian New Zealand Clinical Trials Registry Reference Number: ACTRN12618000638235 anzctr.org.au.


2021 ◽  
Vol 13 (598) ◽  
pp. eabd8034
Author(s):  
Iain Templeman ◽  
Harry Alex Smith ◽  
Enhad Chowdhury ◽  
Yung-Chih Chen ◽  
Harriet Carroll ◽  
...  

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.


2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 51-51
Author(s):  
Katelyn Senkus ◽  
Kristi Crowe-White ◽  
Julie Locher ◽  
Jamy Ard

Abstract Objectives It is imperative to accurately estimate whole body fat percentage (%fat) in order to understand the deleterious nature of excess adiposity on cardiometabolic disease risk. However, cost and accessibility often preclude the use of advanced assessment methods. Relative fat mass (RFM), an emerging estimator of whole body %fat based upon waist circumference, height, and biological sex, has yet to be evaluated in an older adult population. The purpose of this study was to examine the relationship between RFM and gold standard measures of adiposity among older adults, and to evaluate whether changes in RFM reflected changes in %fat following a 12-month lifestyle intervention. Methods This study was ancillary to a randomized controlled trial investigating the effects of a lifestyle intervention with and without intentional energy restriction. (Clinicaltrials.gov #NCT00955903). Older adults with obesity (N = 163, 37.4% male, 70.3 ± 4.7 years) were randomized to one of three groups: exercise only, exercise + nutrient-dense weight maintenance diet, or exercise + nutrient-dense energy restriction of 500 kcal/d. Total and regional adiposity were determined by dual-energy X-ray absorptiometry (DXA) at baseline and 12 months. Data were analyzed using Spearman's correlations, Wilcoxon, Kruskal-Wallis, and linear regression tests. Results At baseline, significant correlations were observed between RFM and DXA whole body %fat (r = 0.751, P &lt; 0.001), DXA total fat (r = 0.353, P &lt; 0.001), and DXA trunk %fat (r = 0.661, P &lt; 0.001). Additionally, RFM was a significant predictor of DXA whole body %fat (P &lt; 0.001) and accounted for 63.5% of model variance. From baseline to 12 months, a significant reduction in RFM was observed among participants in the exercise only and exercise + energy restriction groups (P = 0.020, P &lt; 0.001, respectively). Magnitude of RFM change did not differ among groups. Notably, changes in RFM were significantly correlated with changes in DXA whole body %fat (r = 0.279, P = 0.001) and DXA trunk %fat (r = 0.276, P = 0.001). Conclusions Results support use of RFM as an estimate of whole body %fat, as well as an indicator of its sensitivity to change in fat mass over 12 months in older adults. Incorporation of RFM in cardiometabolic research may provide meaningful information not reflected in conventional body composition measures such as body mass index. Funding Sources NIH


2020 ◽  
Vol 12 (23) ◽  
pp. 9894
Author(s):  
Ana Moradell ◽  
David Navarrete-Villanueva ◽  
Ángel Iván Fernández-García ◽  
Lucía Sagarra-Romero ◽  
Jorge Marín-Puyalto ◽  
...  

The aging of humans is associated with body composition and function deterioration creating a burden on an individual level, but also on a societal one, resulting in an economic burden that is socially unsustainable. This study aimed to evaluate changes in body composition after a 6-month MCT (multicomponent training) and a 4-month detraining period, and to examine the possible influence of energy and macronutrient intake in these changes in frail and pre-frail older adults. A total of 43 participants from the training group (TRAIN) and 28 controls (CON) completed the study protocol. Body weight, body mass index (BMI), waist and hip circumferences, fat mass, fat free mass and fat mass percentage were recorded, with a bio-electrical impedance analyzer, at baseline, after 6 months and four months after finishing the MCT. A food frequency questionnaire was used to estimate energy intake. Mixed effect models did not show differences between groups. CON showed increases in hip circumference and waist (3.20 ± 1.41 and 3.06 ± 1.66 cm, respectively) during the first 6 months. TRAIN showed decreases in BMI (−0.29 ± 0.14), fat mass (−0.86 ± 0.38 kg), body fat percentage (−0.98 ± 0.36%) and increases in waist circumference (3.20 ± 1.41). After detraining, TRAIN group showed increases in fat mas (1.07 ± 0.30 kg), body fat percentage (1.43 ± 0.31%) and waist (3.92 ± 1.38 cm), and decreases in fat free mass (−0.90 ± 0.30 kg). CON group only showed an increase in body fat (1.32 ± 0.47%). Energy intake was negatively associated with hip circumference in the first six months and fat mass during detraining in CON. Energy intake showed positive associations with fat mass in TRAIN during detraining. Only carbohydrates were negatively related to detraining changes in fat free mass and BMI in CON. In conclusion, the MCT reduces adiposity of frail and pre-frail older people, leading to a maintenance of fat free mass. In addition, these interventions should not be stopped in this population in order to improve health sustainability.


Obesity ◽  
2016 ◽  
Vol 24 (2) ◽  
pp. 424-429 ◽  
Author(s):  
Susana Santos ◽  
Romy Gaillard ◽  
Andreia Oliveira ◽  
Henrique Barros ◽  
Albert Hofman ◽  
...  

2021 ◽  
pp. 1-27
Author(s):  
Masoome Piri Damaghi ◽  
Atieh Mirzababaei ◽  
Sajjad Moradi ◽  
Elnaz Daneshzad ◽  
Atefeh Tavakoli ◽  
...  

Abstract Background: Essential amino acids (EAAs) promote the process of regulating muscle synthesis. Thus, whey protein that contains higher amounts of EAA can have a considerable effect on modifying muscle synthesis. However, there is insufficient evidence regarding the effect of soy and whey protein supplementation on body composition. Thus, we sought to perform a meta-analysis of published Randomized Clinical Trials that examined the effect of whey protein supplementation and soy protein supplementation on body composition (lean body mass, fat mass, body mass and body fat percentage) in adults. Methods: We searched PubMed, Scopus, and Google Scholar, up to August 2020, for all relevant published articles assessing soy protein supplementation and whey protein supplementation on body composition parameters. We included all Randomized Clinical Trials that investigated the effect of whey protein supplementation and soy protein supplementation on body composition in adults. Pooled means and standard deviations (SD) were calculated using random-effects models. Subgroup analysis was applied to discern possible sources of heterogeneity. Results: After excluding non-relevant articles, 10 studies, with 596 participants, remained in this study. We found a significant increase in lean body mass after whey protein supplementation weighted mean difference (WMD: 0.91; 95% CI: 0.15, 1.67. P= 0.019). Subgroup analysis, for whey protein, indicated that there was a significant increase in lean body mass in individuals concomitant to exercise (WMD: 1.24; 95% CI: 0.47, 2.00; P= 0.001). There was a significant increase in lean body mass in individuals who received 12 or less weeks of whey protein (WMD: 1.91; 95% CI: 1.18, 2.63; P<0.0001). We observed no significant change between whey protein supplementation and body mass, fat mass, and body fat percentage. We found no significant change between soy protein supplementation and lean body mass, body mass, fat mass, and body fat percentage. Subgroup analysis for soy protein indicated there was a significant increase in lean body mass in individuals who supplemented for 12 or less weeks with soy protein (WMD: 1.48; 95% CI: 1.07, 1.89; P< 0.0001). Conclusion: Whey protein supplementation significantly improved body composition via increases in lean body mass, without influencing fat mass, body mass, and body fat percentage.


Author(s):  
Kara C. Anderson ◽  
Katie R. Hirsch ◽  
Austin M. Peterjohn ◽  
Malia N.M. Blue ◽  
Alexis A. Pihoker ◽  
...  

AbstractNormal weight obesity (NWO) describes individuals who have a normal weight body mass index (BMI), but have an unhealthy amount of body fat. Based on the life-long habits that develop during college, exploring NWO among a college-aged population may be essential in identifying and preventing obesity that develops in early adulthood. This study aimed to characterize NWO among young adults with normal weight BMI. 94 college students (Mean ± SD: Age: 19.6 ± 1.5 yrs; BMI: 21.9 ± 1.8 kg/m2) enrolled during the Fall semester (Aug-Oct) were assessed for body composition by dual energy X-ray absorptiometry to determine body fat percentage, fat mass, lean mass and trunk fat; lifestyle habits were characterized from validated questionnaires. Mean arterial pressure and metabolic biomarkers [total cholesterol, high density lipoproteins, non-high density lipoproteins, and glucose] were evaluated for cardiometabolic health. NWO was defined using data from the National Health and Nutrition Examination Survey (NHANES) for body fat percentage. Data was analyzed by group (NWO vs NWL) and sex. with independent t-tests to investigate continuous data, and chi-square test of independence for categorical data. Rates of NWO for the total sample were 13.8%. Males (n=30) had a higher rate of NWO (26.7%) compared to females (n=64; 7.8%). NWO individuals had higher fat mass (p=0.024), trunk fat (p<0.001), and larger waist to hip ratio (p<0.001) than normal weight lean. NWO also engaged in less vigorous physical activity (p=0.043). The occurrence of NWO among otherwise healthy college students is evident. Identification of these individuals may be an effective component for obesity prevention and treatment. Determining feasible methods to measure body fat in this population is essential, as BMI may mask obesity in a young adult population.


Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2349
Author(s):  
Stephen Keenan ◽  
Matthew B. Cooke ◽  
Regina Belski

Diets utilising intermittent fasting (IF) as a strategic method to manipulate body composition have recently grown in popularity, however, dietary practices involving fasting have also been followed for centuries for religious reasons (i.e., Ramadan). Regardless of the reasons for engaging in IF, the impacts on lean body mass (LBM) may be detrimental. Previous research has demonstrated that resistance training promotes LBM accrual, however, whether this still occurs during IF is unclear. Therefore, the objective of this review is to systematically analyse human studies investigating the effects of variations of IF combined with resistance training on changes in LBM in previously sedentary or trained (non-elite) individuals. Changes in body weight and fat mass, and protocol adherence were assessed as a secondary objective. This review followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. MEDLINE, CINAHL, PubMed and SportDiscus databases were searched for articles investigating IF, combined with resistance training that reported measures of body composition. Eight studies met the eligibility criteria. LBM was generally maintained, while one study reported a significant increase in LBM. Body fat mass or percentage was significantly reduced in five of eight studies. Results suggest that IF paired with resistance training generally maintains LBM, and can also promote fat loss. Future research should examine longer-term effects of various forms of IF combined with resistance training compared to traditional forms of energy restriction. Prospero registration CRD42018103867.


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