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1.
Cancer Med ; 13(5): e7001, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38491821

RESUMO

PURPOSE: Resistance training may offer several unique advantages within breast cancer (BC) survivorship care; however, safety concerns have limited the application of high-intensity compound movements necessary to elicit optimal changes in body composition, strength, and quality of life in this population. The EXERT-BC trial assesses the safety and feasibility of an evidence-based, dose-escalated resistance training regimen among BC survivors, with the goal of improving physical and metabolic function, mobility, muscle mass, and body composition. METHODS: Participants included women with breast cancer underwent a 3-month thrice weekly exercise regimen involving dose escalation of high-intensity compound exercises. Coprimary outcomes included safety and adherence. Pre- and post-regimen assessment included body composition testing, functional mobility and balance, total load (weight × repetitions × sets) across compound exercises, and patient reported quality of life. Pairwise comparison was performed via the paired t test. RESULTS: Fourty participants completed a 3-month exercise regimen, with a median age of 57 years (range, 27-74 years) and 73% having stage 0-2 BC. BC therapies concurrent with exercise included anti-estrogen therapy (80%), radiotherapy (30%), and non-hormonal systemic therapy (15%). No adverse events were observed aside from a single case of self-limited knee pain. Session attendance exceeded a prespecified threshold of 75%, and 98% patients reported ongoing compliance to an exercise regimen following regimen completion. Significant reductions in percent body fat (p < 0.001) and increases in percent muscle mass (p = 0.011) were observed. Significant increases in resting metabolic rate (p = 0.023), bilateral grip strength (p < 0.001), functional movement screen (p < 0.001), bilateral Y-Balance testing (p < 0.001), and Godin questionnaire scores (p < 0.001) were observed. CONCLUSION: A 3-month dose-escalated resistance training regimen comprising high-intensity compound movements appears safe with a high degree of adherence among breast cancer survivors, resulting in demonstrable improvements in body composition, metabolic parameters, strength increases, and patient-reported quality of life.


Assuntos
Neoplasias da Mama , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Composição Corporal , Neoplasias da Mama/terapia , Terapia por Exercício/métodos , Força Muscular/fisiologia , Projetos Piloto , Qualidade de Vida
2.
Sports Med Int Open ; 8: a21930922, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38312924

RESUMO

Purpose EXERT-BC is a dose-escalated resistance training regimen created to improve body composition, strength, and balance in women treated for breast cancer (BC). Herein, we report the interim analysis. Women treated for BC underwent this 3-month exercise regimen in an exercise oncology facility with continual monitoring of load and strength. Twenty women completed the IRB-approved protocol, with a mean age of 57 years (range 41-74). Concurrent therapies included anti-estrogen therapy (73%), chemotherapy (14%), and radiotherapy (23%). 27% of women endorsed prior exercise. Subjects missed an average of 1.75 classes (range 0-7), with all meeting adherence over 75%. No injuries or adverse events were reported aside from muscle soreness and 2 days of knee pain. Significant differences in body composition at completion included reduced body fat (38.2% vs. 36.7%, p=0.003), and increased muscle mass (33.1% vs. 37.1%, p<0.001), functional mobility screening (9.82 vs. 11.73, p=0.018), and Y-balance (left: 72.4 vs. 85.3, p=0.001; right: 70.3 vs. 85.2. p<0.001). Significant increases in load were demonstrated: split squat (p<0.001), trap bar deadlift (p=0.035), inclined dumbbell press (p<0.001), and bird dog rows (p<0.001). Dose-escalated resistance training in women with BC is safe and feasible, endorsing significant improvements across body composition, balance, and strength.

3.
PLoS One ; 19(1): e0296523, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38166036

RESUMO

PURPOSE: Ketogenic diets may positively influence cancer through pleiotropic mechanisms, but only a few small and short-term studies have addressed feasibility and efficacy in cancer patients. The primary goals of this study were to evaluate the feasibility and the sustained metabolic effects of a personalized well-formulated ketogenic diet (WFKD) designed to achieve consistent blood beta-hydroxybutyrate (ßHB) >0.5 mM in women diagnosed with stage IV metastatic breast cancer (MBC) undergoing chemotherapy. METHODS: Women (n = 20) were enrolled in a six month, two-phase, single-arm WFKD intervention (NCT03535701). Phase I was a highly-supervised, ad libitum, personalized WFKD, where women were provided with ketogenic-appropriate food daily for three months. Phase II transitioned women to a self-administered WFKD with ongoing coaching for an additional three months. Fasting capillary ßHB and glucose were collected daily; weight, body composition, plasma insulin, and insulin resistance were collected at baseline, three and six months. RESULTS: Capillary ßHB indicated women achieved nutritional ketosis (Phase I mean: 0.8 mM (n = 15); Phase II mean: 0.7 mM (n = 9)). Body weight decreased 10% after three months, primarily from body fat. Fasting plasma glucose, plasma insulin, and insulin resistance also decreased significantly after three months (p < 0.01), an effect that persisted at six months. CONCLUSIONS: Women diagnosed with MBC undergoing chemotherapy can safely achieve and maintain nutritional ketosis, while improving body composition and insulin resistance, out to six months.


Assuntos
Neoplasias da Mama , Dieta Cetogênica , Resistência à Insulina , Insulinas , Cetose , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Estudos de Viabilidade , Ácido 3-Hidroxibutírico
4.
Clin Nutr ESPEN ; 54: 277-287, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36963874

RESUMO

BACKGROUND: Single doses of exogenous ketone salts (KS) transiently increase circulating beta-hydroxybutyrate (BHB) (∼1 mM; 1-2 h) regardless of starting levels of ketosis; however, no studies have explored how sustained use of KS influences measures of ketonemia and glycemia. OBJECTIVES: To determine the response to a hypocaloric, well-formulated ketogenic diet (KD), with and without the inclusion of two daily racemic KS doses (6 g R-BHB + 6 g S-BHB per serving) on 1) daily fasting capillary R-BHB and glucose (R-BHB/GLUfast), 2) bi-weekly 13 h diurnal BHB and glucose (R-BHB/GLUdiur), 3) three-hours post-KS ingestion kinetics (R-BHBKS), and 4) bi-weekly fasting plasma enantiomer-specific BHB (R/S-BHBplasma). METHODS: Non-diabetic adults with overweight and obesity were randomized to receive a precisely measured hypocaloric KD (∼75 %en of maintenance) for six weeks, supplemented twice-daily with KS or placebo (PL). A non-randomized comparison group was provided an isonitrogenous/isoenergetic low-fat diet (LFD). All meals were provided to subjects. Capillary blood was collected daily to measure R-BHB/GLUfast and hourly for R-BHB/GLUdiur. Plasma was collected to measure R/S-BHBplasma, insulin, fasting glucose, and insulin resistance (HOMA-IR). Total AUC was calculated using the trapezoidal method. RESULTS: Mean R-BHBfast increased significantly during KD + PL (1.0 mM BHB), an effect enhanced 26% during KD + KS. GLUfast AUC was -6% lower during KD + KS versus LFD. Mean R-BHBdiur increased 40% in KD + KS versus KD + PL, whereas GLUdiur decreased 13% during both KDs versus LFD. R-BHBKS peaked (Δ: ∼1 mM) 1 h after the morning KS dose, but not following the afternoon dose. Both R/S-BHBplasma increased during KD independent of KS inclusion. R-BHBplasma was 50-times greater compared to S-BHBplasma, and the KS augmented S-BHBplasma 50% more than PL. Fasting insulin and HOMA-IR decreased after 14 days independent of diet. CONCLUSIONS: A hypocaloric KD was effective at reducing diurnal glucose compared to a LFD independent of weight loss, but twice-daily racemic KS ingestion during KD augmented ketonemia, both as R- and S-BHB, and decreased mean fasting glucose beyond a KD alone. The hypoglycemic effects of KD in combination with exogenous ketones merit further investigation.


Assuntos
Dieta Cetogênica , Cetose , Adulto , Humanos , Ácido 3-Hidroxibutírico , Sais , Corpos Cetônicos , Cetonas , Glucose , Insulina , Jejum
5.
J Am Nutr Assoc ; 42(2): 169-177, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35512774

RESUMO

BACKGROUND: Ketosis has been reported to benefit healthspan and resilience, which has driven considerable interest in development of exogenous ketones to induce ketosis without dietary changes. Bis hexanoyl (R)-1,3-butanediol (BH-BD) is a novel ketone di-ester that can be used as a food ingredient that increases hepatic ketogenesis and blood beta-hydroxybutyrate (BHB) concentrations. METHODS: Here, we provide the first description of blood ketone and metabolite kinetics for up to five hours after consumption of a beverage containing BH-BD by healthy adults (n = 8) at rest in three randomized, cross-over conditions (25 g + Meal (FEDH); 12.5 g + Meal (FEDL) ; 25 g + Fasted (FASTH)). RESULTS: Consumption of BH-BD effectively raised plasma r-BHB concentrations to 0.8-1.7 mM in all conditions, and both peak r-BHB concentration and r-BHB area under the curve were greater with 25 g versus 12.5 g of BH-BD. Urinary excretion of r-BHB was <1 g. Plasma concentration of the non-physiological isoform s-BHB was increased to 20-60 µM in all conditions. BH-BD consumption decreased plasma glucose and free fatty acid concentrations; insulin was increased when BH-BD was consumed with a meal. CONCLUSIONS: These results demonstrate that consumption of BH-BD effectively induces exogenous ketosis in healthy adults at rest.


Assuntos
Ésteres , Cetose , Adulto , Humanos , Ácido 3-Hidroxibutírico , Hidroxibutiratos , Corpos Cetônicos , Cetonas
6.
Sports Med ; 53(1): 75-89, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36175646

RESUMO

There are many benefits to the addition of exercise to cancer treatment and survivorship, particularly with resistance training regimens that target hypertrophy, bone mineral density, strength, functional mobility, and body composition. These goals are best achieved through a series of individualized high-intensity compound movements that mirror functional mobility patterns and sufficiently stress the musculoskeletal system. As a result of adequate stress, the body will engage compensatory cellular mechanisms that improve the structural integrity of bones and muscles, stimulate metabolism and the immune system, optimize functional performance, and minimize mechanical injury risk. The current evidence suggests that application of the above exercise principles, practiced in a safe environment under expert observation, may offer patients with cancer an effective means of improving overall health and cancer-specific outcomes. The following article poses several important questions certified exercise specialists and physicians should consider when prescribing resistance exercise for patients with cancer.


Assuntos
Neoplasias , Treinamento de Força , Humanos , Densidade Óssea , Exercício Físico/fisiologia , Osso e Ossos , Composição Corporal , Força Muscular/fisiologia , Neoplasias/terapia
8.
Nutrients ; 14(6)2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35334791

RESUMO

A growing number of endurance athletes have considered switching from a traditional high-carbohydrate/low-fat (HCLF) to a low-carbohydrate/high-fat (LCHF) eating pattern for health and performance reasons. However, few studies have examined how LCHF diets affect blood lipid profiles in highly-trained runners. In a randomized and counterbalanced, cross-over design, athletes (n = 7 men; VO2max: 61.9 ± 6.1 mL/kg/min) completed six weeks of two, ad libitum, LCHF (6/69/25% en carbohydrate/fat/protein) and HCLF (57/28/15% en carbohydrate/fat/protein) diets, separated by a two-week washout. Plasma was collected on days 4, 14, 28, and 42 during each condition and analyzed for: triglycerides (TG), LDL-C, HDL-C, total cholesterol (TC), VLDL, fasting glucose, and glycated hemoglobin (HbA1c). Capillary blood beta-hydroxybutyrate (BHB) was monitored during LCHF as a measure of ketosis. LCHF lowered plasma TG, VLDL, and TG/HDL-C (all p < 0.01). LCHF increased plasma TC, LDL-C, HDL-C, and TC/HDL-C (all p < 0.05). Plasma glucose and HbA1c were unaffected. Capillary BHB was modestly elevated throughout the LCHF condition (0.5 ± 0.05 mmol/L). Healthy, well-trained, normocholesterolemic runners consuming a LCHF diet demonstrated elevated circulating LDL-C and HDL-C concentrations, while concomitantly decreasing TG, VLDL, and TG/HDL-C ratio. The underlying mechanisms and implications of these adaptive responses in cholesterol should be explored.


Assuntos
Dieta com Restrição de Gorduras , Carboidratos da Dieta , HDL-Colesterol , Estudos Cross-Over , Humanos , Lipídeos , Masculino
10.
Integr Cancer Ther ; 20: 15347354211032283, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34259084

RESUMO

Alpelisib is a α-selective phosphatidylinositol 3-kinase (PI3K) inhibitor approved for treatment of postmenopausal women, and men, with hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-), PIK3CA-mutated, advanced breast cancer (ABC). Hyperglycemia is a common, on-target adverse effect that impairs treatment efficacy and increases the rate of treatment delays, dose reductions, and discontinuation. Currently, there are no clear guidelines on how to manage hyperglycemia due to alpelisib when metformin is not effective. In this case series, we review 3 subjects with ABC that developed hyperglycemia during alpelisib-fulvestrant therapy and were successfully managed with dietary and pharmacologic interventions. These cases provide anecdotal evidence to support the use of sodium-glucose co-transporter-2 inhibitors (SGLT2i) and very low carbohydrate diets to minimize hyperglycemia during alpelisib therapy.


Assuntos
Hiperglicemia , Inibidores do Transportador 2 de Sódio-Glicose , Simportadores , Dieta com Restrição de Carboidratos , Feminino , Glucose , Humanos , Hiperglicemia/induzido quimicamente , Hiperglicemia/tratamento farmacológico , Masculino , Fosfatidilinositol 3-Quinases , Receptor ErbB-2/metabolismo , Sódio , Tiazóis
11.
Nutrients ; 13(6)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198888

RESUMO

BACKGROUND: Foods rich in saturated fatty acids (SFAs) have been discouraged by virtue of their cholesterol-raising potential, but this effect is modulated by the food source and background level of carbohydrate. OBJECTIVE: We aimed to compare the consumption of palm stearin (PS) versus butter on circulating cholesterol responses in the setting of both a low-carbohydrate/high-fat (LC/HF) and high-carbohydrate/low-fat (HC/LF) diet in healthy subjects. We also explored effects on plasma lipoprotein particle distribution and fatty acid composition. METHODS: We performed a randomized, controlled-feeding, cross-over study that compared a PS- versus a Butter-based diet in a group of normocholesterolemic, non-obese adults. A controlled canola oil-based 'Run-In' diet preceded the experimental PS and Butter diets. All diets were eucaloric, provided for 3-weeks, and had the same macronutrient distribution but varied in primary fat source (40% of the total fat). The same Run-In and cross-over experiments were done in two separate groups who self-selected to either a LC/HF (n = 12) or a HC/LF (n = 12) diet track. The primary outcomes were low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein (HDL)-C, triglycerides, and LDL particle distribution. RESULTS: Compared to PS, Butter resulted in higher LDL-C in both the LC/HF (13.4%, p = 0.003) and HC/LF (10.8%, p = 0.002) groups, which was primarily attributed to large LDL I and LDL IIa particles. There were no differences between PS and Butter in HDL-C, triglycerides, or small LDL particles. Oxidized LDL was lower after PS than Butter in LC/HF (p = 0.011), but not the HC/LF group. CONCLUSIONS: These results demonstrate that Butter raises LDL-C relative to PS in healthy normocholesterolemic adults regardless of background variations in carbohydrate and fat, an effect primarily attributed to larger cholesterol-rich LDL particles.


Assuntos
Manteiga , Colesterol/sangue , Dieta/métodos , Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Óleo de Palmeira/administração & dosagem , Adulto , Idoso , Estudos Cross-Over , Dieta/efeitos adversos , Dieta da Carga de Carboidratos/efeitos adversos , Dieta da Carga de Carboidratos/métodos , Dieta com Restrição de Carboidratos/efeitos adversos , Dieta com Restrição de Carboidratos/métodos , Dieta com Restrição de Gorduras/efeitos adversos , Dieta com Restrição de Gorduras/métodos , Dieta Hiperlipídica/efeitos adversos , Dieta Hiperlipídica/métodos , Feminino , Voluntários Saudáveis , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Óleo de Palmeira/química , Adulto Jovem
12.
Nutrients ; 13(3)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33802651

RESUMO

Ketogenic diets (KDs) often contain high levels of saturated fat, which may increase liver fat, but the lower carbohydrate intake may have the opposite effect. Using a controlled feeding design, we compared liver fat responses to a hypocaloric KD with a placebo (PL) versus an energy-matched low-fat diet (LFD) in overweight adults. We also examined the added effect of a ketone supplement (KS). Overweight adults were randomized to a 6-week KD (KD + PL) or a KD with KS (KD + KS); an LFD group was recruited separately. All diets were estimated to provide 75% of energy expenditure. Weight loss was similar between groups (p > 0.05). Liver fat assessed by magnetic resonance imaging decreased after 6 week (p = 0.004) with no group differences (p > 0.05). A subset with nonalcoholic fatty liver disease (NAFLD) (liver fat > 5%, n = 12) showed a greater reduction in liver fat, but no group differences. In KD participants with NAFLD, 92% of the variability in change in liver fat was explained by baseline liver fat (p < 0.001). A short-term hypocaloric KD high in saturated fat does not adversely impact liver health and is not impacted by exogenous ketones. Hypocaloric low-fat and KDs can both be used in the short-term to significantly reduce liver fat in individuals with NAFLD.


Assuntos
Dieta com Restrição de Gorduras , Dieta Cetogênica , Suplementos Nutricionais , Gorduras/análise , Cetonas/uso terapêutico , Fígado/química , Sobrepeso/dietoterapia , Adulto , Dieta com Restrição de Gorduras/métodos , Dieta Cetogênica/métodos , Gorduras/metabolismo , Feminino , Humanos , Fígado/diagnóstico por imagem , Fígado/metabolismo , Imageamento por Ressonância Magnética , Masculino , Sobrepeso/metabolismo
13.
Front Nutr ; 8: 618520, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33869263

RESUMO

Background: Ketogenic diets (KDs) that elevate beta-hydroxybutyrate (BHB) promote weight and fat loss. Exogenous ketones, such as ketone salts (KS), also elevate BHB concentrations with the potential to protect against muscle loss during caloric restriction. Whether augmenting ketosis with KS impacts body composition responses to a well-formulated KD remains unknown. Purpose: To explore the effects of energy-matched, hypocaloric KD feeding (<50 g carbohydrates/day; 1.5 g/kg/day protein), with and without the inclusion of KS, on weight loss and body composition responses. Methods: Overweight and obese adults were provided a precisely defined hypocaloric KD (~75% of energy expenditure) for 6 weeks. In a double-blind manner, subjects were randomly assigned to receive ~24 g/day of a racemic BHB-salt (KD + KS; n = 12) or placebo (KD + PL; n = 13). A matched comparison group (n = 12) was separately assigned to an isoenergetic/isonitrogenous low-fat diet (LFD). Body composition parameters were assessed by dual x-ray absorptiometry and magnetic resonance imaging. Results: The KD induced nutritional ketosis (>1.0 mM capillary BHB) throughout the study (p < 0.001), with higher fasting concentrations observed in KD + KS than KD + PL for the first 2 weeks (p < 0.05). There were decreases in body mass, whole body fat and lean mass, mid-thigh muscle cross-sectional area, and both visceral and subcutaneous adipose tissues (p < 0.001), but no group differences between the two KDs or with the LFD. Urine nitrogen excretion was significantly higher in KD + PL than LFD (p < 0.01) and trended higher in KD + PL compared to KD + KS (p = 0.076), whereas the nitrogen excretion during KD + KS was similar to LFD (p > 0.05). Conclusion: Energy-matched hypocaloric ketogenic diets favorably affected body composition but were not further impacted by administration of an exogenous BHB-salt that augmented ketosis. The trend for less nitrogen loss with the BHB-salt, if manifested over a longer period of time, may contribute to preserved lean mass.

14.
J Strength Cond Res ; 35(5): 1467-1476, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33900267

RESUMO

ABSTRACT: Rosenberg, J, Hyde, PN, Yancy, WS, Ford, KM, and Champ, CE. Quantity of resistance exercise for breast cancer patients: does the dose match the objective? J Strength Cond Res 35(5): 1467-1476, 2021-There is currently a lack of consensus as to what defines exercise and resistance training in the cancer setting and whether current studies comply with exercise guidelines. This study aimed to quantify the available research studies using resistance training exercise interventions in the breast cancer setting for future clinical trial utilization. We systemically reviewed all available resistance exercise studies during and after breast cancer treatment in an attempt to quantify to the prescribed dose and whether regimens aligned with general exercise guidelines to improve functional mobility, body composition, and metabolic function. They were then compared with recommendations set forth by the national committees that create evidence-based exercise guidelines. Fifty studies met the initial criteria, with 35 meeting analysis criteria for evaluation. Fifteen studies evaluated an exercise regimen during cancer treatment, and 20 evaluated a regimen after treatment. The average adherence rates were 84% for all studies. Only 23 studies listed specific exercises used within the protocol. Most exercise regimens relied on open chain movements and machine exercises. Around half of studies met criteria to achieve hypertrophy, and 66% met American College of Sports Medicine exercise guidelines for cancer patients. A minority of breast cancer studies implementing a resistance training exercise regimen prescribed a regimen or specific dose that follows general exercise guidelines. This study highlights a potential deficiency in exercise programs designed for patients with breast cancer, and these findings should be considered in future study design.


Assuntos
Neoplasias da Mama , Treinamento de Força , Composição Corporal , Neoplasias da Mama/terapia , Exercício Físico , Terapia por Exercício , Humanos
15.
J Strength Cond Res ; 34(12): 3326-3330, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33235016

RESUMO

Kraemer, WJ, Caldwell, LK, Post, EM, DuPont, WH, Martini, ER, Ratamess, NA, Szivak, TK, Shurley, JP, Beeler, MK, Volek, JS, Maresh, CM, Todd, JS, Walrod, BJ, Hyde, PN, Fairman, C, and Best, TM. Body composition in elite strongman competitors. J Strength Cond Res 34(12): 3326-3330, 2020-The purpose of this descriptive investigation was to characterize a group of elite strongman competitors to document the body composition of this unique population of strength athletes. Data were collected from eligible competitors as part of a health screening program conducted over 5 consecutive years. Imaging was acquired using dual-energy x-ray absorptiometry (DXA), providing total body measures of fat mass, lean mass, and bone mineral content (BMC). Year to year, testing groups showed a homogenous grouping of anthropometric, body composition, and bone density metrics. Composite averages were calculated to provide an anthropometric profile of the elite strongman competitor (N = 18; mean ± SD): age, 33.0 ± 5.2 years; body height, 187.4 ± 7.1 cm; body mass, 152.9 ± 19.3 kg; body mass index, 43.5 ± 4.8 kg·m; fat mass, 30.9 ± 11.1 kg; lean mass, 118.0 ± 11.7 kg, body fat, 18.7 ± 6.2%, total BMC, 5.23 ± 0.41 kg, and bone mineral density, 1.78 ± 0.14 g·cm. These data demonstrate that elite strongman competitors are among the largest human male athletes, and in some cases, they are at the extreme limits reported for body size and structure. Elite strongman competitors undergo a high degree of mechanical stress, providing further insight into the potent role of physical training in mediating structural remodeling even into adulthood. Such data provide a glimpse into a unique group of competitive athletes pushing the limits not only of human performance but also of human physiology.


Assuntos
Atletas , Composição Corporal , Absorciometria de Fóton , Adulto , Índice de Massa Corporal , Densidade Óssea , Humanos , Masculino
16.
Am J Physiol Endocrinol Metab ; 319(6): E995-E1007, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32985255

RESUMO

Animal data indicate that ketogenic diets are associated with improved mitochondrial function, but human data are lacking. We aimed to characterize skeletal muscle mitochondrial changes in response to a ketogenic diet combined with exercise training in healthy individuals. Twenty-nine physically active adults completed a 12-wk supervised exercise program after self-selection into a ketogenic diet (KD, n = 15) group or maintenance of their habitual mixed diet (MD, n = 14). Measures of metabolic health and muscle biopsies (vastus lateralis) were obtained before and after the intervention. Mitochondria were isolated from muscle and studied after exposure to carbohydrate (pyruvate), fat (palmitoyl-l-carnitine), and ketone (ß-hydroxybutyrate+acetoacetate) substrates. Compared with MD, the KD resulted in increased whole body resting fat oxidation (P < 0.001) and decreased fasting insulin (P = 0.019), insulin resistance [homeostatic model assessment of insulin resistance (HOMA-IR), P = 0.022], and visceral fat (P < 0.001). The KD altered mitochondrial function as evidenced by increases in mitochondrial respiratory control ratio (19%, P = 0.009), ATP production (36%, P = 0.028), and ATP/H2O2 (36%, P = 0.033) with the fat-based substrate. ATP production with the ketone-based substrate was four to eight times lower than with other substrates, indicating minimal oxidation. The KD resulted in a small decrease in muscle glycogen (14%, P = 0.035) and an increase in muscle triglyceride (81%, P = 0.006). These results expand our understanding of human adaptation to a ketogenic diet combined with exercise. In conjunction with weight loss, we observed altered skeletal muscle mitochondrial function and efficiency, an effect that may contribute to the therapeutic use of ketogenic diets in various clinical conditions, especially those associated with insulin resistance.


Assuntos
Dieta Cetogênica , Exercício Físico/fisiologia , Mitocôndrias Musculares/fisiologia , Músculo Esquelético/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/fisiologia , Adulto , Gorduras na Dieta/farmacologia , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Humanos , Insulina/metabolismo , Resistência à Insulina/fisiologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Mitocôndrias Musculares/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/ultraestrutura , Oxirredução
17.
J Am Coll Nutr ; 39(4): 290-300, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32330107

RESUMO

Background: Acute ingestion of ketone supplements alters metabolism and potentially exercise performance. No studies to date have evaluated the impact of co-ingestion of ketone salts with caffeine and amino acids on high intensity exercise performance, and no data exists in Keto-Adapted individuals.Methods: We tested the performance and metabolic effects of a pre-workout supplement containing beta-hydroxybutyrate (BHB) salts, caffeine, and amino acids (KCA) in recreationally-active adults habitually consuming a mixed diet (Keto-Naïve; n = 12) or a ketogenic diet (Keto-Adapted; n = 12). In a randomized and balanced manner, subjects consumed either the KCA consisting of ∼7 g BHB (72% R-BHB and 28% S-BHB) with ∼100 mg of caffeine, and amino acids (leucine and taurine) or Water (control condition) 15 minutes prior to performing a staged cycle ergometer time to exhaustion test followed immediately by a 30 second Wingate test.Results: Circulating total BHB concentrations increased rapidly after KCA ingestion in KN (154 to 732 µM) and KA (848 to 1,973 µM) subjects and stayed elevated throughout recovery in both groups. Plasma S-BHB increased >20-fold 15 minutes after KCA ingestion in both groups and remained elevated throughout recovery. Compared to Water, KCA ingestion increased time to exhaustion 8.3% in Keto-Naïve and 9.8% in Keto-Adapted subjects (P < 0.001). There was no difference in power output during the Wingate test between trials. Peak lactate immediately after exercise was higher after KCA (∼14.9 vs 12.7 mM).Conclusion: These results indicate that pre-exercise ingestion of a moderate dose of R- and S-BHB salts combined with caffeine, leucine and taurine improves high-intensity exercise performance to a similar extent in both Keto-Adapted and Keto-Naïve individuals.


Assuntos
Ácido 3-Hidroxibutírico/administração & dosagem , Aminoácidos/administração & dosagem , Ciclismo/fisiologia , Cafeína/administração & dosagem , Suplementos Nutricionais , Fenômenos Fisiológicos da Nutrição Esportiva , Ácido 3-Hidroxibutírico/sangue , Adaptação Fisiológica , Adolescente , Adulto , Estudos Cross-Over , Dieta Cetogênica , Ingestão de Alimentos/fisiologia , Teste de Esforço , Feminino , Humanos , Ácido Láctico/sangue , Masculino , Pessoa de Meia-Idade , Resistência Física/efeitos dos fármacos , Sais/farmacologia , Adulto Jovem
18.
JCI Insight ; 4(12)2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31217353

RESUMO

BACKGROUNDMetabolic syndrome (MetS) is highly correlated with obesity and cardiovascular risk, but the importance of dietary carbohydrate independent of weight loss in MetS treatment remains controversial. Here, we test the theory that dietary carbohydrate intolerance (i.e., the inability to process carbohydrate in a healthy manner) rather than obesity per se is a fundamental feature of MetS.METHODSIndividuals who were obese with a diagnosis of MetS were fed three 4-week weight-maintenance diets that were low, moderate, and high in carbohydrate. Protein was constant and fat was exchanged isocalorically for carbohydrate across all diets.RESULTSDespite maintaining body mass, low-carbohydrate (LC) intake enhanced fat oxidation and was more effective in reversing MetS, especially high triglycerides, low HDL-C, and the small LDL subclass phenotype. Carbohydrate restriction also improved abnormal fatty acid composition, an emerging MetS feature. Despite containing 2.5 times more saturated fat than the high-carbohydrate diet, an LC diet decreased plasma total saturated fat and palmitoleate and increased arachidonate.CONCLUSIONConsistent with the perspective that MetS is a pathologic state that manifests as dietary carbohydrate intolerance, these results show that compared with eucaloric high-carbohydrate intake, LC/high-fat diets benefit MetS independent of whole-body or fat mass.TRIAL REGISTRATIONClinicalTrials.gov Identifier: NCT02918422.FUNDINGDairy Management Inc. and the Dutch Dairy Association.


Assuntos
Carboidratos da Dieta/metabolismo , Síndrome Metabólica/metabolismo , Obesidade/metabolismo , Redução de Peso , Ácido 8,11,14-Eicosatrienoico/sangue , Adulto , Idoso , Ácido Araquidônico/sangue , LDL-Colesterol/metabolismo , Estudos Cross-Over , Dieta , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Mil Med ; 184(9-10): e538-e547, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30877806

RESUMO

INTRODUCTION: Ketogenic diets (KDs) that elevate ketones into a range referred to as nutritional ketosis represent a possible nutrition approach to address the emerging physical readiness and obesity challenge in the military. An emerging body of evidence demonstrates broad-spectrum health benefits attributed to being in nutritional ketosis, but no studies have specifically explored the use of a KD in a military population using daily ketone monitoring to personalize the diet prescription. MATERIALS AND METHODS: To evaluate the feasibility, metabolic, and performance responses of an extended duration KD, healthy adults (n = 29) from various military branches participated in a supervised 12-wk exercise training program. Fifteen participants self-selected to an ad libitum KD guided by daily measures of capillary blood ketones and 14 continued their normal mixed diet (MD). A battery of tests were performed before and after the intervention to assess changes in body mass, body composition, visceral fat, liver fat, insulin sensitivity, resting energy metabolism, and physical performance. RESULTS: All KD subjects were in nutritional ketosis during the intervention as assessed by daily capillary beta-hydroxybutyrate (ßHB) (mean ßHB 1.2 mM reported 97% of all days) and showed higher rates of fat oxidation indicative of keto-adaptation. Despite no instruction regarding caloric intake, the KD group lost 7.7 kg body mass (range -3.5 to -13.6 kg), 5.1% whole-body percent fat (range -0.5 to -9.6%), 43.7% visceral fat (range 3.0 to -66.3%) (all p < 0.001), and had a 48% improvement in insulin sensitivity; there were no changes in the MD group. Adaptations in aerobic capacity, maximal strength, power, and military-specific obstacle course were similar between groups (p > 0.05). CONCLUSIONS: US military personnel demonstrated high adherence to a KD and showed remarkable weight loss and improvements in body composition, including loss of visceral fat, without compromising physical performance adaptations to exercise training. Implementation of a KD represents a credible strategy to enhance overall health and readiness of military service members who could benefit from weight loss and improved body composition.


Assuntos
Dieta Cetogênica/normas , Militares/estatística & dados numéricos , Condicionamento Físico Humano/fisiologia , Ácido 3-Hidroxibutírico/análise , Ácido 3-Hidroxibutírico/sangue , Tecido Adiposo/fisiologia , Adulto , Composição Corporal/fisiologia , Dieta Cetogênica/métodos , Dieta Cetogênica/estatística & dados numéricos , Feminino , Humanos , Masculino , Estado Nutricional , Ohio , Condicionamento Físico Humano/métodos , Condicionamento Físico Humano/estatística & dados numéricos , Aptidão Física/fisiologia , Estudos Prospectivos , Redução de Peso/fisiologia
20.
Tomography ; 5(4): 358-366, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31893234

RESUMO

Excess visceral adipose tissue (VAT) and VAT volume relative to subcutaneous adipose tissue (SAT) are associated with elevated health risks. This study compares fat measurements by dual-energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI). In total, 21 control subjects (Control) and 16 individuals with metabolic syndrome (MetSyn) were scanned by DXA and MRI. The region measured by MRI was matched to the android region defined by DXA, and MRI reproducibility was also evaluated. In addition, liver fat fraction was quantified via MRI and whole-body fat by DXA. VAT measurements are interchangeable between DXA and MRI in the Control (R = 0.946), MetSyn (R = 0.968), and combined cohort (R = 0.983). VAT/SAT ratio did not differ in the Control group (P = .10), but VAT/SAT ratio measured by DXA was significantly higher in the MetSyn group (P < .01) and the combined (P = .03) cohort. Intraobserver (ICC = 0.998) and interobserver (ICC = 0.977) reproducibility of MRI VAT measurements was excellent. Liver fat fraction by MRI was higher (P = .001) in MetSyn (12.4% ± 7.6%) than in controls (2.6% ± 2.2%), as was whole-body fat percentage by DXA (P = .001) between the MetSyn (42.0% ± 8.1%) and Control groups (26.7% ± 6.9%). DXA and MRI VAT are interchangeable when measured over an anatomically matched region of the abdomen, while SAT and VAT/SAT ratio differ between the 2 modalities.


Assuntos
Absorciometria de Fóton , Gordura Intra-Abdominal/diagnóstico por imagem , Imageamento por Ressonância Magnética , Feminino , Humanos , Masculino , Síndrome Metabólica/diagnóstico por imagem , Gordura Subcutânea/diagnóstico por imagem
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