Loss Of Fat-free Mass Research Articles

Testosterone status following short-term, severe energy deficit is associated with fat-free mass loss in U.S. Marines.

The objective of this study was to determine metabolic and physiological differences between males with low testosterone (LT) versus those with normal testosterone (NT) following a period of severe energy deficit. In this secondary analysis, 68 male US Marines (mean ± SD, 24.6 ± 2.4 y) were dichotomized by testosterone concentration (< or ≥ 10.5 nmol/L as determined from a single blood sample collected between 0600–0630 after an 8–10 h overnight fast by automated immunoassay) following 7 days of near complete starvation (~300 kcal consumed/d, ~85% energy deficit) during Survival, Evasion, Resistance, and Escape (SERE) training. Dietary intake was assessed before (PRE) SERE. Body composition (dual‐energy x‐ray absorptiometry and peripheral quantitative computed tomography) and whole‐body protein turnover (15N alanine) were assessed before (PRE) and after (POST) SERE. Mean testosterone concentrations decreased PRE (17.5 ± 4.7 nmol/L) to POST (9.8 ± 4.0 nmol/L, p < 0.0001). When volunteers were dichotomized by POST testosterone concentrations [NT (n = 24) 14.1 ± 3.4 vs. LT (n = 44): 7.5 ± 1.8 nmol/L, p < 0.0001], PRE BMI, total fat mass, trunk fat mass, and testosterone were greater and the diet quality score and total carbohydrate intake were lower in NT compared to LT (p ≤ 0.05). LT lost more fat‐free mass and less fat mass, particularly in the trunk region, compared to NT following SERE (p‐interaction≤0.044). Whole‐body protein synthesis, net balance, and flux decreased and whole‐body protein breakdown increased from PRE to POST in both groups (p‐time ≤0.025). Following short‐term, severe energy deficit, Marines who exhibited low testosterone had greater fat‐free mass loss than those who maintained normal testosterone concentrations. Altering body composition and dietary strategies prior to physical training that elicits severe energy deficit may provide an opportunity to attenuate post‐training decrements in testosterone and its associated effects (e.g., loss of lean mass, performance declines, fatigue).

Testosterone Undecanoate Administration Prevents Fat-Free Mass Loss During Strenuous Multi-Stressor Military Operations

PURPOSE: The efficacy of administering testosterone (T) to restore eugonadal concentrations during multi-stressor, sustained military operations (SUSOPS) that suppress endogenous T synthesis to prevent declines in lean mass and physical performance is not well described. Therefore, the objective of this study was to test the effects of T on androgen status, body composition, and physical performance during a simulated SUSOPS. METHODS: After a baseline phase (P1), 32 healthy young males (26.5 ± 4.4 y) received a single injection of either T undecanoate (750 mg; TEST) or placebo (PLA) before completing four consecutive, 5-d simulated SUSOPS cycles (P2). Each cycle consisted of two low-stress days (~1230 kcal/d exercise-induced energy deficit [EDef]; 8 h sleep/night) and three high-stress days (~2800 kcal/d EDef; 4 h sleep/night). P2 was followed by a 23-d recovery period (P3). Circulating hormones, 4-compartment measures of body composition, and physical performance (vertical jump, 3-repetition maximum [RM] deadlift, Wingate anaerobic test, treadmill VO2peak, and 2.5-mile weighted ruck march) were examined at the end of each phase. RESULTS: Total T in TEST was greater by the end of P2 than P1 (mean ± SE between group difference at the end of P2: 6.7 ± 2.6 nmol/L, p < 0.001), which returned to P1 values in P3, but total T did not change in PLA. Despite increases in free T in TEST throughout P2, free T at the end of P2 was not different from P1, but decreased from P1 to P2 in PLA (-1.2 ± 0.6 pmol/L, p = 0.04) and was greater at the end of P3 compared to P1 in PLA (p < 0.05). FFM was maintained across phases in TEST, but decreased from P1 to P2 in PLA (-2.3 ± 1.0 kg, p = 0.02) and recovered in P3. Total body mass and fat mass decreased from P1 to P2 (p < 0.05) and recovered by P3 regardless of treatment. Vertical jump height, 3-RM deadlift, and Wingate peak power decreased, and 2.5-mile ruck march time increased from P1 to P2 (all p < 0.05) and recovered by P3 regardless of treatment. CONCLUSION: Administering T before a 20-d, simulated SUSOPS maintained eugonadal T concentrations and prevented FFM loss without impacting androgen status in recovery. However, T use did not attenuate performance decrements in response to the multi-stressor SUSOPS.

Malnutrition risk screening: New insights in a new era

Twenty years ago, ESPEN published its "Guidelines for nutritional screening 2002", with the note that these guidelines were based on the evidence available until 2002, and that they needed to be updated and adapted to current state of knowledge in the future. Twenty years have passed, and tremendous progress has been made in the field of malnutrition risk screening. Many screening tools have been developed and validated for different patient groups and different health care settings. Some countries even have introduced mandatory screening for malnutrition at admission to hospital. Yet, changes in society and healthcare require a reflection on current practice and policies regarding malnutrition risk screening. In this opinion paper, we share our perspectives on malnutrition risk screening in the twenty-twenties, addressing the changing and varying profile of the malnourished individual, the goals of screening and screening tools (i.e., preventive or reactive), the construct of malnutrition risk (i.e., screening for risk factors or screening for existing malnutrition), and screening alongside a patient's journey.

Effects of physical activity and dietary supplement on fat free mass and bone mass density during weight loss – a systematic review and meta-analysis.

Background: After a diet- or surgery induced weight loss almost 1/3 of lost weight consists of fat free mass (FFM) if carried out without additional therapy. Exercise training and a sufficient supply of protein, calcium and vitamin D is recommended to reduce the loss of FFM. Objective: To investigate the effect of exercise training, protein, calcium, and vitamin D supplementation on the preservation of FFM during non-surgical and surgical weight loss and of the combination of all interventions together in adults with obesity. Methods: A systematic review was performed with a pairwise meta-analysis and an exploratory network meta-analysis according to the PRISMA statement. Results: Thirty studies were included in the quantitative analysis. The pairwise meta-analysis showed for Exercise Training + High Protein vs. High Protein a moderate and statistically significant effect size (SMD 0.45; 95% CI 0.04 to 0.86), for Exercise Training + High Protein vs. Exercise Training a high but statistically not significant effect size (SMD 0.91; 95% CI -0.59 to 2.41) and for Exercise Training alone vs. Control a moderate but statistically not significant effect size (SMD 0.67; 95% CI -0.25 to 1.60). In the exploratory network meta-analysis three interventions showed statistically significant effect sizes compared to Control and all of them included the treatment Exercise Training. Conclusions: Results underline the importance of exercise training and a sufficient protein intake to preserve FFM during weight loss in adults with obesity. The effect of calcium and vitamin D supplementation remains controversial and further research are needed.

Impact of sleeve gastrectomy on renal function in patients with morbid obesity: a 1-year prospective cohort study.

Obesity is an independent risk factor for renal injury. A more favorable metabolic environment following weight loss may theoretically lead to improved renal function. We aimed to evaluate the evolution of renal function one year after sleeve gastrectomy in a large prospective cohort of patients with morbid obesity and assess the influence of fat-free mass (FFM) changes. We prospectively included obese patients admitted for sleeve gastrectomy between February 2014 and November 2016. We also included a historical observational cohort of patients undergoing sleeve gastrectomy between January 2013 and January 2014 who had FFM evaluation. Patients were systematically evaluated 1year after surgery. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. The FFM was estimated by analyzing computerized tomography (CT) scan sections from CT systematically performed 2days and 1year after sleeve gastrectomy to detect surgery complications. Five hundred sixty-three patients fulfilled the inclusion criteria. The mean age was 41.2 ± 0.5years. The mean body mass index was 43.5 ± 0.3kg/m2 and 20.4, 30.5, and 30.7% of the included patients had type 2 diabetes, hypertension, and dyslipidemia, respectively. One hundred fifteen patients were excluded and four hundred forty-eight patients were finally included in the analysis. The eGFR was significantly higher 1year after sleeve gastrectomy than before surgery (87.8 ± 0.9 versus 86.1 ± 0.9, p < 0.01). There was no difference in terms of post-surgery FFM loss between patients with an improved eGFR and those without (6.7 ± 0.3kg versus 6.8 ± 0.5kg, p = 0.9). Furthermore, post-surgery changes in the eGFR did not correlate with the amount of FFM loss (r = 0.1, p = 0.18). Renal function assessed by eGFR is significantly improved at 1-year post-sleeve gastrectomy, independent of changes in skeletal muscle mass.

Effect of Exercise on Energy Expenditure and Body Composition in Astronauts Onboard the International Space Station: Considerations for Interplanetary Travel.

Body mass (BM) loss and body composition (BC) changes threaten astronauts' health and mission success. However, the energetic contribution of the exercise countermeasure to these changes has never been investigated during long-term missions. We studied energy balance and BC in astronauts during 6-month missions onboard the International Space Station. Before and after at least 3months in space, BM, BC, total and activity energy expenditure (TEE and AEE) were measured using the doubly labeled water method in 11 astronauts (2011-2017). Physical activity (PA) was assessed by the SensewearPro® activity-device. Three-month spaceflight decreased BM (-1.20kg [SE 0.5]; P = 0.04), mainly due to non-significant fat-free mass loss (FFM; -0.94kg [0.59]). The decrease in walking time (-63.2min/day [11.5]; P < 0.001) from preflight was compensated by increases in non-ambulatory activities (+ 64.8min/day [18.8]; P < 0.01). Average TEE was unaffected but a large interindividual variability was noted. Astronauts were stratified into those who maintained (stable_TEE; n = 6) and those who decreased (decreased_TEE; n = 5) TEE and AEE compared to preflight data. Although both groups lost similar BM, FFM was maintained and FM reduced in stable_TEE astronauts, while FFM decreased and FM increased in decreased_TEE astronauts (estimated between-group-difference (EGD) in ΔFFMindex [FFMI] 0.87kg/m2, 95% CI + 0.32 to + 1.41; P = 0.01, ΔFMindex [FMI] -1.09kg/m2, 95% CI -2.06 to -0.11kg/m2; P = 0.03). The stable_TEE group had higher baseline FFMI, and greater baseline and inflight vigorous PA than the decreased_TEE group (P < 0.05 for all). ΔFMI and ΔFFMI were respectively negatively and positively associated with both ΔTEE and ΔAEE. Both ground fitness and inflight overall PA are associated with spaceflight-induced TEE and BC changes and thus energy requirements. New instruments are needed to measure real-time individual changes in inflight energy balance components.

Association between Fat-Free Mass Loss after Diet and Exercise Interventions and Weight Regain in Women with Overweight.

This study aimed to determine if percent fat-free mass loss (% FFML) after diet alone, diet plus aerobic, or diet plus resistance exercise is a predictor of weight regain in women with overweight. One hundred and forty-one premenopausal women with overweight (body mass index, 28 ± 1 kg·m -2 ; age, 35 ± 6 yr) enrolled in a weight loss program to achieve a body mass index <25 kg·m -2 (diet alone, diet plus resistance, or diet plus aerobic exercise) and were followed for 1 yr. Body weight and composition (with dual-energy x-ray absorptiometry) were measured at baseline, after weight loss, and at 1 yr. Participants lost 12.1 ± 2.6 kg of body weight, 11.3 ± 2.5 kg of fat mass, and 0.5 ± 1.6 kg of fat-free mass during the weight loss intervention, followed by weight regain at 1 yr (6.0 ± 4.4 kg, 51.3% ± 37.8%; P < 0.001 for all). % FFML was -3.6 ± 12.4, and a greater % FFML was associated with more weight regain ( r = -0.216, P = 0.01, n = 141), even after adjusting for the intervention group ( β = -0.07; 95% confidence interval, -0.13 to -0.01; P = 0.017). % FFML is a significant predictor of weight regain in premenopausal women with overweight. These results support strategies for conserving fat-free mass during weight loss, such as resistance training. Future research should try to identify the mechanisms, at the level of both appetite and energy expenditure, responsible for this association.

Preservation of fat-free mass in the first year after bariatric surgery: a systematic review and meta-analysis of 122 studies and 10,758 participants.

The main goal of bariatric surgery (BS) in patients with morbid obesity is reducing body mass and fat mass (FM). However, body mass loss is systematically accompanied by a decline in fat-free mass (FFM). We aimed to examine the time-course effect of BS on FFM and body FFM percentage (FFM%) in individuals with morbid obesity by conducting a systematic review and meta-analysis of controlled adult human trials. We searched PubMed, Scopus, Embase, Institute for Scientific Information Web of Science, and Cochrane databases within the period from October 2002 to May 2021, with no restriction in the English language, to find studies assessing the effect of BS on FFM and FFM% in patients with morbid obesity. A meta-analysis of 122 studies carried out on data of 10,758 patients with morbid obesity after BS showed that BS was associated with a substantial decrease in FFM at 1 (-3.47 kg [95% confidence interval [CI]: -3.88, -3.07]), 3 (-5.59 kg [95% CI: -6.01, -5.17], 6 (-6.61 kg [95% CI: -7.25, -5.98]), and 12 (-8.34 kg [95% CI: -9.04, -7.63]) months after the surgery; however, the FFM% increased at 3 (6.51% [95% CI: 5.00, 8.02]), 6 (8.56% [95% CI: 6.81, 10.31], and 12 (11.29% [95% CI: 8.94, 13.64]) months after the surgery. BS was associated with sustained declines in FFM and increases in FFM% from 1-12 months with no indication of plateau phase postoperatively. These findings emphasize that postbariatric care should focus more on FFM loss during the first year after surgery.

Sex-specific differences in metabolic outcomes after sleeve gastrectomy and intermittent fasting in obese middle-aged mice.

Despite the high prevalence of obesity among middle-aged subjects, it is unclear if sex differences in middle age affect the metabolic outcomes of obesity therapies. Accordingly, in this study, middle-aged obese female and male mice were randomized to one of three groups: sleeve gastrectomy (SG), sham surgery ad libitum (SH-AL), or sham surgery with weight matching to SG through intermittent fasting with calorie restriction (SH-IF). Comprehensive measures of energy and glucose homeostasis, including energy intake, body weight, energy expenditure, glucose and insulin tolerance, and interscapular brown adipose tissue (iBAT) sympathetic innervation density were obtained. At the end of 8 wk, SG and SH-IF females had better metabolic outcomes than their male counterparts. SG females had improved weight loss maintenance, preservation of fat-free mass (FFM), higher total energy expenditure (TEE), normal locomotor activity, and reduced plasma insulin and white adipose tissue (WAT) inflammatory markers. SH-IF females also had lower plasma insulin and WAT inflammatory markers, and higher TEE than SH-IF males, despite their lower FFM. In addition, SH-IF females had higher iBAT sympathetic nerve density than SG and SH-AL females, whereas there were no differences among males. Notably, SH-IF mice of both sexes had the most improved glucose tolerance, highlighting the benefits of fasting, irrespective of weight loss. Results from this study demonstrate that in middle-aged obese mice, female sex is associated with better metabolic outcomes after SG or IF with calorie restriction. Clinical studies are needed to determine if sex differences should guide the choice of obesity therapies.NEW & NOTEWORTHY SG or IF with calorie restriction produces better metabolic outcomes in females than in males. IF with calorie restriction prevents metabolic adaptation, even in the face of fat-free mass loss. IF with calorie restriction in females only, is associated with increased iBAT sympathetic innervation, which possibly mitigates reductions in energy expenditure secondary to fat-free mass loss. Lastly, IF leads to better glucose homeostasis than SG, irrespective of sex.

439-P: Disparate Effects of Menopause on Cardiovascular Risk in Women with Type 1 Diabetes

Introduction: Women with type 1 diabetes (T1D) are at increased risk for cardiovascular disease (CVD) , and menopause increases CVD risk. However, little is known about menopause and CVD risk in T1D. Methods: Women with (N=64) and without T1D (n=63) ages 47-55 years were examined for CVD risk factors and surrogate CVD markers: pulse wave velocity (PWV) , augmentation pressure (AP) and pulse height (PH) , brachial artery distensibility (BrachD) , and subendocardial viability index (SVI) . Body composition was measured by Dual Xray Absorptiometry. Menopausal status was determined by self-report. CVD markers were examined by diabetes and menopausal status using linear regression models adjusted for age. Results: Mean ± SD age was 51±2.5 years in women with T1D and 51 ± 2.4 years in women without diabetes (p=0.32) . The percentage postmenopausal did not differ (30% vs. 32%, p=0.8) between T1D and nondiabetes women. As shown in the table, women with T1D had higher systolic blood pressure and measures of arterial stiffness (PWV, AP, PH, and BrachD) and lower SVI than women without diabetes. Menopause was associated with a greater loss in fat free mass and a greater increase in PWV and AP among women with T1D compared to women without diabetes. Conclusions: Women with T1D have worse CVD markers, and menopause is associated with greater increases in arterial stiffness and loss in lean body mass than in nondiabetes women, independent of age. Disclosure H.K.Wise: None. E.Malecha: None. C.J.Chartier-logan: None. L.Pyle: None. A.Keshawarz: None. J.K.Snell-bergeon: Stock/Shareholder; GlaxoSmithKline plc. Funding American Diabetes Association (7-13-CD-10)

Age- and sex-specific effects of a long-term lifestyle intervention on body weight and cardiometabolic health markers in adults with prediabetes: results from the diabetes prevention study PREVIEW

Aims/hypothesisLifestyle interventions are the first-line treatment option for body weight and cardiometabolic health management. However, whether age groups or women and men respond differently to lifestyle interventions is under debate. We aimed to examine age- and sex-specific effects of a low-energy diet (LED) followed by a long-term lifestyle intervention on body weight, body composition and cardiometabolic health markers in adults with prediabetes (i.e. impaired fasting glucose and/or impaired glucose tolerance).MethodsThis observational study used longitudinal data from 2223 overweight participants with prediabetes in the multicentre diabetes prevention study PREVIEW. The participants underwent a LED-induced rapid weight loss (WL) period followed by a 3 year lifestyle-based weight maintenance (WM) intervention. Changes in outcomes of interest in prespecified age (younger: 25–45 years; middle-aged: 46–54 years; older: 55–70 years) or sex (women and men) groups were compared.ResultsIn total, 783 younger, 319 middle-aged and 1121 older adults and 1503 women and 720 men were included in the analysis. In the available case and complete case analyses, multivariable-adjusted linear mixed models showed that younger and older adults had similar weight loss after the LED, whereas older adults had greater sustained weight loss after the WM intervention (adjusted difference for older vs younger adults −1.25% [95% CI −1.92, −0.58], p<0.001). After the WM intervention, older adults lost more fat-free mass and bone mass and had smaller improvements in 2 h plasma glucose (adjusted difference for older vs younger adults 0.65 mmol/l [95% CI 0.50, 0.80], p<0.001) and systolic blood pressure (adjusted difference for older vs younger adults 2.57 mmHg [95% CI 1.37, 3.77], p<0.001) than younger adults. Older adults had smaller decreases in fasting and 2 h glucose, HbA1c and systolic blood pressure after the WM intervention than middle-aged adults. In the complete case analysis, the above-mentioned differences between middle-aged and older adults disappeared, but the direction of the effect size did not change. After the WL period, compared with men, women had less weight loss (adjusted difference for women vs men 1.78% [95% CI 1.12, 2.43], p<0.001) with greater fat-free mass and bone mass loss and smaller improvements in HbA1c, LDL-cholesterol and diastolic blood pressure. After the WM intervention, women had greater fat-free mass and bone mass loss and smaller improvements in HbA1c and LDL-cholesterol, while they had greater improvements in fasting glucose, triacylglycerol (adjusted difference for women vs men −0.08 mmol/l [−0.11, −0.04], p<0.001) and HDL-cholesterol.Conclusions/interpretationOlder adults benefited less from a lifestyle intervention in relation to body composition and cardiometabolic health markers than younger adults, despite greater sustained weight loss. Women benefited less from a LED followed by a lifestyle intervention in relation to body weight and body composition than men. Future interventions targeting older adults or women should take prevention of fat-free mass and bone mass loss into consideration.Clinical trial registration numberClinicalTrials.gov NCT01777893.Graphical abstract

Body composition in amyotrophic lateral sclerosis subjects and its effect on disease progression and survival

Motor neuron degeneration and malnutrition alter body composition in amyotrophic lateral sclerosis (ALS). Resulting losses of weight, fat mass (FM), and fat-free mass (FFM) shorten survival. Nutritional management relies on body weight or BMI; neither reliably indicates malnutrition nor differentiates body compartments. We aimed to 1) develop an equation to compute FM and FFM using clinical data, validated against DXA; and 2) examine the effect of computed FM and FFM on disease course and survival. We studied 364 ALS patients from 3 cohorts. In Cohort #1 we used logistic regression on clinical and demographic data to create an equation (test cohort). In Cohort #2 we validated FM and FFM computed using this equation against DXA (validation cohort). In Cohort #3, we examined the effect of computed body composition on disease course and survival. In Cohort #1 (n=29) the model incorporated sex, age, BMI, and bulbar-onset to create an equation to estimate body fat: % body fat=1.73 - [19.80*gender (1 if male or 0 if female)] + [0.25*weight (kg)] + [0.95*BMI (kg/m2)] - (5.20*1 if bulbar-onset or *0 if limb-onset). In Cohort #2 (n=104), body composition using this equation, compared to other published equations, showed the least variance from DXA values. In Cohort #3 (n=314), loss of body composition over 6 mo was greater in males. Adjusted survival was predicted by low baseline FM (HR: 1.39; 95% CI: 1.07, 1.80), and loss of FM (HR: 1.87; 95% CI: 1.30, 2.69) and FFM (HR: 1.73; 95% CI: 1.20, 2.49) over 6 mo. Our equation broadens the traditional nutritional evaluation in clinics and reliably estimates body composition. Measuring body composition could target FM as a focus for nutritional management to ensure adequate energy intake and complement measures, such as the ALS functional rating scale-revised score and forced vital capacity, currently used.

Ongoing Community-Based Whole-Food, Plant-Based Lifestyle Effectively Preserves Muscle Mass during Body Mass Loss

Body fat and muscle mass showed opposing associations with mortality. The results of research on the effectiveness of popular body mass (BM) loss diets in obese subjects showed 20 to 30% loss of muscle mass within the total BM loss; conversely, when the subjects used a whole-food, plant-based (WFPB) diet, the loss was up to 42%. Therefore, we suggest an improvement. The aim of this retrospective analysis of data was to examine the assessment of changes in the body composition of 217 participants from all over Slovenia who joined our ongoing, community-based WFPB lifestyle programme from 2016 to 2021 and underwent two successive measurements of medically approved bioelectrical impedance. The WFPB lifestyle programme consisted of (i) nutrition, (ii) physical activity (PA) and (iii) a support system. The primary outcomes included the (vector of) change of body fat mass (BFM) per body height (BH), fat-free mass (FFM) per BH and whole-body phase angle (PhA) from the initial values to the first follow-up (FU) of the whole sample and for both sexes. Further, we examined the FFM change within the total BM loss according to their BMI classification and depending on how much BM they lost (5 kg &lt; BM ≥ 5 kg) within the FU time (103.6 ± 89.8 day). Participants experienced a decrease in BFM per BH (−0.02 ± 0.02 kg/cm, p &lt; 0.001), no change in FFM and an increase in PhA (0.2 ± 0.7°, p &lt; 0.001). Importantly, the participants in the obesity BMI class achieved only partial FFM preservation (−1.5 ± 3.6 kg, p = 0.032 of FFM loss (20%) within −7.5 ± 6.1 kg, p &lt; 0.001 of BM loss). However, the participants who lost BM &lt; 5 kg had a significantly increased FFM (0.8 ± 3.2 kg, p = 0.001 of FFM (57%) within −1.4 ± 1.8 kg, p &lt; 0.001 of BM loss), whereas the participants who lost BM ≥ 5 kg experienced a decrease in FFM (−2.2 ± 3.9 kg, p &lt; 0.001 of FFM (−25%) within −8.8 ± 5.2 kg, p &lt; 0.001 of BM loss). To conclude, the WFPB lifestyle, on average, effectively preserved FFM during BM and/or BFM loss among the normal and pre-obesity BMI classes but only partially among the obese BMI class and those who lost ≥ 5 kg of BM. Importantly, a customized PA strategy is needed for obese BMI class participants, where general resistance training is not possible or safe in order to preserve their muscle mass more effectively. In addition, muscle mass preservation is important for further improvements of BM, body composition and visual body image.

Association Between Body Mass Index and Incident Dementia Among Community-Dwelling Older Adults: The Shanghai Aging Study.

The relationship between body mass index (BMI) and dementia is inconclusive. Undesirable loss of fat-free mass is a risk factor for cognitive decline while obesity is also a risk factor for cardio-metabolic disorders among the older adults. This study aimed to examine the association between BMI and incident all-cause dementia among Chinese older adults using a prospective study. Participants were 1,627 community residents aged 60 or older without dementia from the Shanghai Aging Study. Cox regression models, incorporated with restricted cubic splines, were used to explore a nonlinear association between baseline BMI and risk of all-cause dementia as measured by hazard ratio (HR) using both frequentist and Bayesian approach. We diagnosed 136 incident dementia cases during the mean follow-up of 5.3 years. Compared with moderate BMI (18.5-24.0 kg/m2), low BMI (< 18.5 kg/m2) were related to an increased risk of dementia with the HR as 3.38 (95% CI 1.50-7.63), while high BMI (≥24.0 kg/m2) showed a decreased risk of dementia without statistical significance (HR = 0.91, 95% CI 0.60 to 1.39). Sensitivity analysis in participants without central obesity indicated that the association was still significant with even higher HR. Bayesian approach presented the similar results. Our result indicates that low BMI may contribute to high risk of incident dementia, even in individuals without central obesity.

Dietary Recommendations for Post-COVID-19 Syndrome.

At the beginning of the coronavirus disease (COVID-19) pandemic, global efforts focused on containing the spread of the virus and avoiding contagion. Currently, it is evident that health professionals should deal with the overall health status of COVID-19 survivors. Indeed, novel findings have identified post-COVID-19 syndrome, which is characterized by malnutrition, loss of fat-free mass, and low-grade inflammation. In addition, the recovery might be complicated by persistent functional impairment (i.e., fatigue and muscle weakness, dysphagia, appetite loss, and taste/smell alterations) as well as psychological distress. Therefore, the appropriate evaluation of nutritional status (assessment of dietary intake, anthropometrics, and body composition) is one of the pillars in the management of these patients. On the other hand, personalized dietary recommendations represent the best strategy to ensure recovery. Therefore, this review aimed to collect available evidence on the role of nutrients and their supplementation in post-COVID-19 syndrome to provide a practical guideline to nutritionists to tailor dietary interventions for patients recovering from COVID-19 infections.

Short-Term Changes on Body Composition After Sleeve Gastrectomy and One Anastomosis Gastric Bypass.

Introduction: Changes in body composition after different bariatric surgeries have been studied extensively, but most of them have emphasized on Roux-en-Y gastric bypass. Only a few studies have assessed the effects of sleeve gastrectomy (SG). Also, the effect of one anastomosis gastric bypass (OAGB) on body composition is not fully apprehended. Furthermore, there is no agreement on how much fat-free mass (FFM) loss is tolerable in weight loss interventions. Therefore, we decided to assess the reduction in fat mass (FM) and FFM at 1, 3, 6, and 12 months after two types of bariatric surgery in a single center. Methods: In the current retrospective cross-sectional study, the patients' hospital records were analyzed. We included patients who had SG or OAGB and a complete 1-year follow-up record. We recorded demographic data as well as weight, body mass index (BMI), FM, and FFM before and at 1, 3, 6, and 12 months after surgery in a predesigned checklist. Results: We analyzed 311 patients (43 males and 268 females) in the SG (N = 192, 61.7%) and OAGB (N = 119, 38.3%) groups. Both the SG and OAGB groups demonstrated a statistically significant reduction in weight, BMI, FM, and FFM indices at 12 months after the intervention (P < .001). Moreover, no statistically significant difference was observed between the SG and OAGB groups regarding the mean of all body composition indices at 3, 6, and 12 months after the intervention. Conclusion: We found that SG and OAGB effectively decreased weight and body composition indices, comprising FM and FFM, with no significant difference between each other.

Stress and the gut-brain axis: Cognitive performance, mood state, and biomarkers of blood-brain barrier and intestinal permeability following severe physical and psychological stress

BackgroundPhysical and psychological stress alter gut-brain axis activity, potentially causing intestinal barrier dysfunction that may, in turn, induce cognitive and mood impairments through exacerbated inflammation and blood brain barrier (BBB) permeability. These interactions are commonly studied in animals or artificial laboratory environments. However, military survival training provides an alternative and unique human model for studying the impacts of severe physical and psychological stress on the gut-brain axis in a realistic environment. PurposeTo determine changes in intestinal barrier and BBB permeability during stressful military survival training and identify relationships between those changes and markers of stress, inflammation, cognitive performance, and mood state. Materials and methodsSeventy-one male U.S. Marines (25.2 ± 2.6 years) were studied during Survival, Evasion, Resistance, and Escape (SERE) training. Measurements were conducted on day 2 of the 10-day classroom phase of training (PRE), following completion of the 7.5-day field-based simulation phase of the training (POST), and following a 27-day recovery period (REC). Fat-free mass (FFM) was measured to assess the overall physiologic impact of the training. Biomarkers of intestinal permeability (liposaccharide-binding protein [LBP]) and BBB permeability (S100 calcium-binding protein B [S100B]), stress (cortisol, dehydroepiandrosterone sulfate [DHEA-S] epinephrine, norepinephrine) and inflammation (interleukin-6 [IL-6], high-sensitivity C-reactive protein [hsCRP]) were measured in blood. Cognitive performance was assessed by psychomotor vigilance (PVT) and grammatical reasoning (GR) tests, and mood state by the Profile of Mood States (total mood disturbance; TMD), General Anxiety Disorder-7 (GAD-7), and Patient Health (PHQ-9) questionnaires. ResultsFFM, psychomotor vigilance, and LBP decreased from PRE to POST, while TMD, anxiety, and depression scores, and S100B, DHEA-S, IL-6, norepinephrine, and epinephrine concentrations all increased (all p ≤ 0.01). Increases in DHEA-S were associated with decreases in body mass (p = 0.015). Decreases in FFM were associated with decreases in LBP concentrations (p = 0.015), and both decreases in FFM and LBP were associated with increases in TMD and depression scores (all p < 0.05) but not with changes in cognitive performance. Conversely, increases in S100B concentrations were associated with decreases in psychomotor vigilance (p < 0.05) but not with changes in mood state or LBP concentrations. ConclusionsEvidence of increased intestinal permeability was not observed in this military survival training-based model of severe physical and psychological stress. However, increased BBB permeability was associated with stress and cognitive decline, while FFM loss was associated with mood disturbance, suggesting that distinct mechanisms may contribute to decrements in cognitive performance and mood state during the severe physical and psychological stress experienced during military survival training.

Effects of physical activity and dietary supplement on fat free mass and bone mass density during weight loss – a systematic review and meta-analysis.

Background: After a diet- or surgery induced weight loss almost 1/3 of lost weight consists of fat free mass (FFM) if carried out without additional therapy. Exercise training and a sufficient supply of protein, calcium and vitamin D is recommended to reduce the loss of FFM. Objective: To investigate the effect of exercise training, protein, calcium, and vitamin D supplementation on the preservation of FFM during non-surgical and surgical weight loss and of the combination of all interventions together in adults with obesity. Methods: A systematic review was performed with a pairwise meta-analysis and an exploratory network meta-analysis according to the PRISMA statement. Results: Thirty studies were included in the quantitative analysis. The pairwise meta-analysis showed for Exercise Training + High Protein vs. High Protein a moderate and statistically significant effect size (SMD 0.45; 95% CI 0.04 to 0.86), for Exercise Training + High Protein vs. Exercise Training a high but statistically not significant effect size (SMD 0.91; 95% CI -0.59 to 2.41) and for Exercise Training alone vs. Control a moderate but statistically not significant effect size (SMD 0.67; 95% CI -0.25 to 1.60). In the exploratory network meta-analysis three interventions showed statistically significant effect sizes compared to Control and all of them included the treatment Exercise Training. Conclusions: Results underline the importance of exercise training and a sufficient protein intake to preserve FFM during weight loss in adults with obesity. The effect of calcium and vitamin D supplementation remains controversial and further research are needed.

Is the Peri-Bariatric Surgery Exercise Program Effective in Adults with Obesity: a Systematic Review.

The number of people with obesity continues to increase. Bariatric surgery is the most effective treatment for severe obesity. However, this surgery also has disadvantages, such as an increased risk of excessive loss of fat-free mass, lean body mass, and muscle mass compared to other weight loss interventions. PubMed and Cochrane Library database including articles in English, Dutch, French, and German were used. From the 3609 retrieved references, 20 articles were selected. Compared with the control group, physical exercise improved body mass index (5 of 13 articles), weight loss (7 of 17 articles), functional capacity (2 of 5 articles), muscle strength (1 of 1 article), fat-free mass (3 of 5 articles), cardiorespiratory endurance (4 of 6 articles), and quality of life (2 of 4 articles) in obese patients undergoing BS. Current data is suggestive of positive effects of exercise on body mass index, weight loss, functional capacity, muscle strength, fat-free mass, cardiorespiratory endurance, and quality of life in obese patients undergoing bariatric surgery. However, our conclusions are limited because of the heterogeneity of programs and short studies. Further research is needed to determine the most effective physical exercise program in peri-bariatric surgery.

Why exercise by itself is often ineffective for weight loss but crucial for weight management

The prevalence of obesity is increasing worldwide, and excess body weight is associated with a substantially increased risk of adverse health conditions. Exercise supports the prevention and management of obesity; however, when used for weight loss, exercise (even at high volumes) is usually relatively ineffective, frequently producing less weight loss than expected based on measured energy expenditure. The difference between observed and expected weight loss is called compensation and it is primarily caused by increases in energy intake in response to exercise (compensatory eating). On the other hand, it has been shown that energy balance and body weight are better regulated in individuals with moderate to high levels of physical activity (i.e., energy intake = energy expenditure) compared to those with a sedentary lifestyle (energy expenditure &lt; energy intake), demonstrating that physical activity and exercise are crucial for long-term maintenance of a healthy weight. Weight loss approaches should combine dietary components (calorie restriction) and physical activity for increased success. Calorie restriction facilitates weight loss while physical activity can support the conservation of fat-free mass to avoid a state of increased hunger, often occurring following calorie restriction interventions due to the associated loss in fat-free mass, which ultimately encourages weight regain.