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Older adults are threatened by the risk of muscle atrophy and excess accumulation of adipose tissue. The objective of this study was to determine whether an essential amino acid enriched meal replacement would reduce excess fat and foster skeletal muscle retention, potentially improving physical function in this cohort.Using a double blind, randomized controlled trial, we compared the influence of an experimental meal replacement enriched with essential amino acids (EMR) to a commercially available, widely used meal replacement (Optifast®) provided once/day (q.d.) for four weeks on body composition, skeletal muscle and physical function in obese older participants. Twenty-eight individuals completed either EMR (n = 13) or Optifast® (n = 15) supplementation protocols. Measurements of body composition, thigh skeletal muscle cross-sectional area (CSA), blood panels, intrahepatic lipid, and physical function were completed pre- and post-supplementation.Body fat mass, visceral fat mass and volume, and intrahepatic lipid were reduced with EMR but not with Optifast®. Thigh muscle CSA increased (Δ 2.4 ± 3.0 cmBeneficial alterations in fat and muscle support the use of EMR-based meal replacements in obese older adults.ISRCTN registry under Reference Number ISRCTN15814848.

We have previously demonstrated that the acute ingestion of essential amino acids may augment net protein balance in the elderly. Using a double blind, randomized controlled trial, our objective was to compare an experimental meal replacement enriched with essential amino acids (EMR) compared to a commercial meal replacement (Optifast®) provided once/day (q.d.) for four weeks on body composition and physical function in older, obese participants. Twenty-seven individuals (69±5 yrs; body mass index of 32±4 kg/m2) were randomly assigned to EMR (n=13) or Optifast® (n=15) supplementation. Measurements of body composition, skeletal muscle cross-sectional area (CSA), intrahepatic lipid and physical function were completed pre- and post-supplementation. Body mass, fat mass, and visceral fat mass were reduced with EMR but not altered with Optifast®. Thigh muscle CSA increased ( 4.1 ± 1.9 cm2, P = 0.03) with EMR but not Optifast®. There was a significant increase in the distance covered during the six-minute walk test with EMR ( 21±26 m) but no change in Optifast® ( 22±54 m). Improvements in body composition and physical function support the efficacious use of EMR-based meal replacements in the obese elderly.

Wild game consumption has been associated with health benefits but the acute influence on human protein metabolism remains unknown. We compared feeding-induced responses of equivalent amounts of free-range reindeer (FR) and commercial beef (CB) on protein kinetics using stable isotope methodology. Seven participants (age: 40 ± 14 years; body mass index: 24 ± 3 kg/m2) completed two randomised studies, ingesting 2 oz of FR or CB. L-[ring 2H5]phenylalanine & L-[ring 2H2]tyrosine were delivered via primed, continuous intravenous infusion. Blood samples were collected during the basal period and following consumption of FR or CB. Feeding-induced changes in whole-body protein synthesis (PS), protein breakdown (PB), and net protein balance (NB) were determined via plasma sample isotope enrichment analysis by gas chromatography-mass spectrometry; plasma essential amino acid (EAA) concentrations were determined by liquid chromatography-electrospray ionisation-mass spectrometry. Plasma post-prandial EAA concentrations were higher with FR compared to CB (P

Background: Physical activity is recommended to mitigate the incidence of obesity, but delivery of community wide initiatives is cumbersome. The challenges met by such programs are magnified when implementation transpires in the remote villages of Alaska. To overcome the difficulty of this challenge in the Arctic, the Skiku/AK Nordic cross-country skiing program was developed. The objective of this study was to evaluate whether access to Skiku/AK Nordic program would promote physical activity levels that met the daily recommendations for physical activity in Alaska Native children. Methods: Eight children (4 females and 4 males; 10±2 years/age) were recruited from Kaktovik, Alaska for participation in this study. Expert coaches and staff provided one week of cross-country ski instruction and access to ski equipment. Physical activity was monitored using ActiGraph GT3X+ accelerometers. Data collected from the devices was then downloaded and analyzed using ActiLife software. Results: The participants expended ~586 calories/day devoted to physical activity. Light and moderate physical activity was 68±38 minutes/day and 447±248 minutes/day, respectively. Conclusions: Delivery of the Skiku/AK Nordic program promoted favorable levels of physical activity in Alaska Native children. Further research is needed to assess the longitudinal and seasonal effectiveness of the Skiku/AK Nordic program.

We have previously reported negative energy balance and health benefits during an Alaska backcountry expeditionary hunting (ABEH) immersion in two males. The purpose of our present study was to increase the number of participants, include females, and evaluate macronutrient intake and serum lipids. Four men (age: 46 ± 6 year, BMI: 26 ± 1 kg/m2) and three women (age: 46 ± 11 year, BMI: 25 ± 3 kg/m2) were recruited. Doubly labeled water methodology and dietary recall were utilized to assess energy expenditure and energy intake, respectively. Data were collected during pre‐ and post‐ABEH visits. Body composition was measured using dual‐energy x‐ray absorptiometry and the cross‐sectional area of skeletal muscle in the upper leg (XT), and intrahepatic lipid (IHL) was determined using magnetic resonance imaging and/or spectroscopy (MRI/MRS). Blood parameters were measured by LabCorp. Paired T‐tests were used for statistical analysis. Data are reported as mean ± SD and considered significant at p, The majority of the scientific literature on exercise training has focused on standardized concepts. We assert that movement constancy of the hunter gatherer lifestyle may offer protection against metabolic abnormalities but has been largely understudied. In the context of unscripted negative energy balance, muscle preservation, and rapid improvements in metabolic biomarkers were demonstrated in both healthy females and males during an Alaskan backcountry hunting expedition.

Wild game consumption has been associated with health benefits, but the influence on protein metabolism remains unknown. We compared the feeding-induced response to 2 oz of free-range reindeer (FR) versus commercial beef (CB) using stable isotope methodology. Seven male and female participants (age: 38±12 years; body mass index: 24±3 kg/m2) completed two studies using a randomized, crossover design in which they ingested 2 oz of FR or CB. L-[ring 2H5]phenylalanine & L-[ring 2H2]tyrosine were delivered via primed, continuous intravenous infusion. Blood samples were collected during the basal period and following consumption of FR or CB. Feeding-induced changes in whole body protein synthesis (PS), protein breakdown (PB), and net protein balance (NB) were determined via analysis of plasma samples for phenyalanine and tyrosine enrichment by gas chromatography mass spectrometry; plasma essential amino acid concentrations were determined by liquid chromatography-electrospray ionization-mass spectrometry. Plasma post-prandial essential amino acid (EAA) concentrations were higher with the ingestion of FR compared to CB (P=0.02). The acute feeding-induced response in PS was not different in either trial, but PB was reduced with the ingestion of FR compared to CB (P

Purpose The Yukon Arctic Ultra is considered the longest and coldest ultraendurance event in the world. Cold exposure and exercise has been reported to influence circulating levels of myokines, adipokines, and hepatokines that may influence considerable alterations in the regulation of metabolism. The purpose of the study was to evaluate the influence of the Yukon Arctic Ultra (430-mile event) on potential activators of brown fat, metabolites, and body composition in healthy individuals. Methods Eight male and female participants (mean ± SEM: age, 44 ± 3 yr; body mass index, 23.4 ± 0.9) were recruited for participation. Blood samples were collected at pre-event, mid-event, and post-event checkpoints. Results The temperature during the event ranged from -45°C to -8°C. Because of these extremely challenging conditions, 50% of the participants withdrew from competition by the 300-mile mark, and those that surpassed 300 miles lost a significant (P = 0.002; P = 0.01) amount of body weight (76 ± 5 kg to 73 ± 4 kg) and fat mass (13 ± 1 kg to 12 ± 3 kg), respectively. With respect to serum irisin, there was a trend (P = 0.06) toward significance from pre-event (1033 ± 88 ng·mL), mid-event (1265 ± 23 ng·mL) to post-event (1289 ± 24 ng·mL). Serum meteorin-like and fibroblast growth factor-21 remained stable throughout the event. There were no changes in creatinine, acetoacetate, acetate, and valine. Serum lactate decreased (P = 0.04) during the event. Conclusions The influence of cold exposure and extreme physical exertion may promote substantial increases in serum irisin, and specific alterations in substrate metabolism that largely preserve skeletal muscle and physiological resilience.

Excess alcohol consumption is a top risk factor for death and disability. Fatty liver will likely develop and the risk of liver disease increases. We have previously demonstrated that an essential amino acid supplement (EAAS) improved protein synthesis and reduced intrahepatic lipid in the elderly. The purpose of this exploratory pilot study was to initiate the evaluation of EAAS on intrahepatic lipid (IHL), body composition, and blood lipids in individuals with mild to moderate alcohol use disorder (AUD). Following consent, determination of eligibility, and medical screening, 25 participants (18 males at 38 &plusmn, 15 years/age and 7 females at 34 &plusmn, 18 years/age) were enrolled and randomly assigned to one of two dosages: a low dose (LD: 8 g of EAAS twice/day (BID)) or high dose (HD: 13 g of EAAS BID). Five of the twenty-five enrolled participants dropped out of the intervention. Both groups consumed the supplement BID for 4 weeks. Pre- and post-EAAS administration, IHL was determined using magnetic resonance imaging/spectroscopy, body composition was analyzed using dual-energy X-ray absorptiometry, and blood parameters were measured by LabCorp. T-tests were used for statistical analysis and considered significant at p &lt, 0.05. While there was no significant change in IHL in the LD group, there was a significant 23% reduction in IHL in the HD group (p = 0.02). Fat mass, lean tissue mass, bone mineral content, and blood lipids were not altered. Post-EAAS phosphatidylethanol was elevated and remained unchanged in LD at 407 &plusmn, 141 ng/mL and HD at 429 &plusmn, 196 ng/mL, indicating chronic and excess alcohol consumption. The HD of the proprietary EAAS formulation consumed BID seemed to lower IHL in individuals with mild to moderate AUD. We suggest that further studies in a larger cohort be conducted to more completely address this important area of investigation.

The purported healthy aspects of subsistence foods have led to the popularity of the Paleo diet. There has been very little focus, surprisingly, on health benefits derived from the nomadic nature of humans during the Paleolithic era. The purpose of our study was to examine total energy expenditure (TEE), total energy intake (TEI), body composition, blood lipids, and intrahepatic lipid in humans during a 12‐day Alaskan backcountry expeditionary hunting (ABEH) immersion. Four healthy men (age: 42 ± 3 year, BMI: 27 ± 1 kg/m2) were recruited for the study. TEE was measured using the doubly labeled water method and a food diary was utilized to assess TEI. Body composition was measured using dual energy X‐ray absorptiometry (DXA); cross‐sectional area of the thigh (XT) and intrahepatic lipid (IHL) were measured using molecular imaging. Blood samples were collected for the measurement of blood lipids. DXA, XT, IHL, and blood data were collected pre‐ and immediately post‐ABEH. Results were analyzed using paired t‐tests and considered significant at P