RESUMEN
BACKGROUND: Green tea catechins may play a role in body weight regulation through interactions with the gut microbiota. AIM: We examined whether green tea supplementation for 12 weeks induces changes in composition of the human gut microbiota. METHODS: 58 Caucasian men and women were included in a randomized, placebo-controlled design. For 12 weeks, subjects consumed either green tea (>0.56 g/d epigallocatechin-gallate + 0.28 â¼ 0.45 g/d caffeine) or placebo capsules. Fecal samples were collected twice (baseline, vs. week 12) for analyses of total bacterial profiles by means of IS-profiling, a 16S-23S interspacer region-based profiling method. RESULTS: No significant changes between baseline and week 12 in subjects receiving green tea or placebo capsules, and no significant interactions between treatment (green tea or placebo) and time (baseline and week 12) were observed for body composition. Analysis of the fecal samples in subjects receiving green tea and placebo showed similar bacterial diversity and community structures, indicating there were no significant changes in bacterial diversity between baseline and week 12 in subjects receiving green tea capsules or in subjects receiving placebo capsules. No significant interactions were observed between treatment (green tea or placebo) and time (baseline and week 12) for the gut microbial diversity. Although, there were no significant differences between normal weight and overweight subjects in response to green tea, we did observe a reduced bacterial alpha diversity in overweight as compared to normal weight subjects (p = 0.002). CONCLUSION: Green tea supplementation for 12 weeks did not have a significant effect on composition of the gut microbiota. TRIAL REGISTRATION: ClinicalTrials.gov NCT01556321.
Asunto(s)
Cafeína/administración & dosificación , Catequina/análogos & derivados , Microbioma Gastrointestinal/efectos de los fármacos , Adulto , Composición Corporal/efectos de los fármacos , Cafeína/farmacología , Catequina/administración & dosificación , Catequina/farmacología , Suplementos Dietéticos , Esquema de Medicación , Heces/microbiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Té/química , Población Blanca , Adulto JovenRESUMEN
Green tea catechins mixed with caffeine have been proposed as adjuvants for maintaining or enhancing energy expenditure and for increasing fat oxidation, in the context of prevention and treatment of obesity. These catechins-caffeine mixtures seem to counteract the decrease in metabolic rate that occurs during weight loss. Their effects are of particular importance during weight maintenance after weight loss. Other metabolic targets may be fat absorption and the gut microbiota composition, but these effects still need further investigation in combination with weight loss. Limitations for the effects of green tea catechins are moderating factors such as genetic predisposition related to COMT-activity, habitual caffeine intake, and ingestion combined with dietary protein. In conclusion, a mixture of green tea catechins and caffeine has a beneficial effect on body-weight management, especially by sustained energy expenditure, fat oxidation, and preservation of fat free body-mass, after energy restriction induced body-weight loss, when taking the limitations into account.
Asunto(s)
Peso Corporal/efectos de los fármacos , Catequina/administración & dosificación , Suplementos Dietéticos , Té/química , Animales , Peso Corporal/genética , Cafeína/farmacología , Catecol O-Metiltransferasa/genética , Estimulantes del Sistema Nervioso Central/farmacología , Grasas/metabolismo , Microbioma Gastrointestinal/fisiología , Humanos , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
BACKGROUND: Based on controlled 36 h experiments a higher dietary protein intake causes a positive protein balance and a negative fat balance. A positive net protein balance may support fat free mass accrual. However, few data are available on the impact of more prolonged changes in habitual protein intake on whole-body protein metabolism and basal muscle protein synthesis rates. OBJECTIVE: To assess changes in whole-body protein turnover and basal muscle protein synthesis rates following 12 weeks of adaptation to a low versus high dietary protein intake. METHODS: A randomized parallel study was performed in 40 subjects who followed either a high protein (2.4 g protein/kg/d) or low protein (0.4 g protein/kg/d) energy-balanced diet (30/35/35% or 5/60/35% energy from protein/carbohydrate/fat) for a period of 12 weeks. A subgroup of 7 men and 8 women (body mass index: 22.8±2.3 kg/m2, age: 24.3±4.9 y) were selected to evaluate the impact of prolonged adaptation to either a high or low protein intake on whole body protein metabolism and basal muscle protein synthesis rates. After the diet, subjects received continuous infusions with L-[ring-2H5]phenylalanine and L-[ring-2H2]tyrosine in an overnight fasted state, with blood samples and muscle biopsies being collected to assess post-absorptive whole-body protein turnover and muscle protein synthesis rates in vivo in humans. RESULTS: After 12 weeks of intervention, whole-body protein balance in the fasted state was more negative in the high protein treatment when compared with the low protein treatment (-4.1±0.5 vs -2.7±0.6 µmol phenylalanine/kg/h;P<0.001). Whole-body protein breakdown (43.0±4.4 vs 37.8±3.8 µmol phenylalanine/kg/h;P<0.03), synthesis (38.9±4.2 vs 35.1±3.6 µmol phenylalanine/kg/h;P<0.01) and phenylalanine hydroxylation rates (4.1±0.6 vs 2.7±0.6 µmol phenylalanine/kg/h;P<0.001) were significantly higher in the high vs low protein group. Basal muscle protein synthesis rates were maintained on a low vs high protein diet (0.042±0.01 vs 0.045±0.01%/h;P = 0.620). CONCLUSIONS: In the overnight fasted state, adaptation to a low-protein intake (0.4 g/kg/d) does not result in a more negative whole-body protein balance and does not lower basal muscle protein synthesis rates when compared to a high-protein intake. TRIAL REGISTRATION: Clinicaltrials.gov NCT01551238.
Asunto(s)
Dieta con Restricción de Proteínas , Proteínas en la Dieta/administración & dosificación , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Adulto , Proteínas en la Dieta/metabolismo , Ayuno/sangre , Femenino , Glucosa/metabolismo , Humanos , Insulina/metabolismo , Masculino , Nitrógeno/metabolismo , Fenilalanina/sangre , Biosíntesis de Proteínas , Tirosina/sangre , Adulto JovenRESUMEN
BACKGROUND: Green tea (GT) extract may play a role in body weight regulation. Suggested mechanisms are decreased fat absorption and increased energy expenditure. OBJECTIVE: We examined whether GT supplementation for 12 wk has beneficial effects on weight control via a reduction in dietary lipid absorption as well as an increase in resting energy expenditure (REE). METHODS: Sixty Caucasian men and women [BMI (in kg/m²): 18-25 or >25; age: 18-50 y] were included in a randomized placebo-controlled study in which fecal energy content (FEC), fecal fat content (FFC), resting energy expenditure, respiratory quotient (RQ), body composition, and physical activity were measured twice (baseline vs. week 12). For 12 wk, subjects consumed either GT (>0.56 g/d epigallocatechin gallate + 0.28-0.45 g/d caffeine) or placebo capsules. Before the measurements, subjects recorded energy intake for 4 consecutive days and collected feces for 3 consecutive days. RESULTS: No significant differences between groups and no significant changes over time were observed for the measured variables. Overall means ± SDs were 7.2 ± 3.8 g/d, 6.1 ± 1.2 MJ/d, 67.3 ± 14.3 kg, and 29.8 ± 8.6% for FFC, REE, body weight, and body fat percentage, respectively. CONCLUSION: GT supplementation for 12 wk in 60 men and women did not have a significant effect on FEC, FFC, REE, RQ, and body composition.
Asunto(s)
Fármacos Antiobesidad/uso terapéutico , Camellia sinensis/química , Grasas de la Dieta/metabolismo , Suplementos Dietéticos , Absorción Intestinal , Sobrepeso/prevención & control , Extractos Vegetales/uso terapéutico , Adiposidad , Adolescente , Adulto , Metabolismo Basal , Índice de Masa Corporal , Grasas de la Dieta/antagonistas & inhibidores , Heces/química , Femenino , Manipulación de Alimentos , Fármacos Gastrointestinales/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Sobrepeso/metabolismo , Hojas de la Planta/química , Método Simple Ciego , Adulto JovenRESUMEN
INTRODUCTION: Green tea(GT) is able to increase energy expenditure(EE) and fat oxidation(FATox) via inhibition of catechol-O-methyl transferase(COMT) by catechins. However, this does not always appear unanimously because of large inter-individual variability. This may be explained by different alleles of the functional COMT Val108/158Met polymorphism that are associated with COMT enzyme activity; high-activity enzyme, COMT(H)(Val/Val genotype), and low-activity COMT(L)(Met/Met genotype). METHODS: Fourteen Caucasian subjects (BMI: 22.2±2.3 kg/m2, age: 21.4±2.2 years) of whom 7 with the COMT(H)-genotype and 7 with the COMT(L)-genotype were included in a randomized, cross-over study in which EE and substrate oxidation were measured with a ventilated-hood system after decaffeinated GT and placebo(PL) consumption. RESULTS: At baseline, EE, RQ, FATox and carbohydrate oxidation(CHOox) did not differ between groups. Significant interactions were observed between COMT genotypes and treatment for RQ, FATox and CHOox (p<0.05). After GT vs. PL, EE(GT: 62.2 vs. PL: 35.4 kJ.3.5 hrs; p<0.01), RQ(GT: 0.80 vs. PL: 0.83; p<0.01), FATox(GT: 18.3 vs. PL: 15.3 g/d; p<0.001) and CHOox(GT: 18.5 vs. PL: 24.3 g/d; p<0.001) were significantly different for subjects carrying the COMT(H) genotype, but not for subjects carrying the COMT(L) genotype (EE, GT: 60.3 vs. PL: 51.7 kJ.3.5 hrs; NS), (RQ, GT: 0.81 vs. PL: 0.81; NS), (FATox, GT: 17.3 vs. PL: 17.0 g/d; NS), (CHOox, GT: 22.1 vs. PL: 21.4 g/d; NS). CONCLUSION: Subjects carrying the COMT(H) genotype increased energy expenditure and fat-oxidation upon ingestion of green tea catechins vs, placebo, whereas COMT(L) genotype carriers reacted similarly to GT and PL ingestion. The differences in responses were due to the different responses on PL ingestion, but similar responses to GT ingestion, pointing to different mechanisms. The different alleles of the functional COMT Val108/158Met polymorphism appear to play a role in the inter-individual variability for EE and FATox after GT treatment. TRIAL REGISTRATION: Nederlands Trial register NTR1918.
Asunto(s)
Camellia sinensis/química , Catequina/farmacología , Catecol O-Metiltransferasa/genética , Metabolismo Energético/genética , Genotipo , Metabolismo de los Lípidos/genética , Polimorfismo Genético , Adulto , Catecol O-Metiltransferasa/química , Estudios Cruzados , Femenino , Humanos , Masculino , Oxidación-Reducción , Proyectos Piloto , Población Blanca/genéticaRESUMEN
Addition of capsaicin (CAPS) to the diet has been shown to increase satiety; therefore, CAPS is of interest for anti-obesity therapy. We investigated the effects of CAPS on appetite profile and ad libitum energy intake in relation to energy balance. Fifteen subjects (seven women and eight men, age: 29.7 ± 10.8yrs, BMI: 23.3 ± 2.9 kg/m(2)) underwent four conditions in a randomized crossover design in 36 hour sessions in a respiration chamber; they received 100% of their daily energy requirements in the conditions "100%Control" and "100%CAPS", and 75% of their daily energy requirements in the conditions "75%Control" and "75%CAPS", followed by an ad libitum dinner. In the 100%CAPS and 75%CAPS conditions, CAPS was given at a dose of 2.56 mg (1.03 g of red chili pepper, 39,050 Scoville heat units) with every meal. Satiety (P < 0.05) and fullness (P = 0.01) were measured every waking hour and before and after every meal using visual analogue scales, and were higher in the 100%CAPS versus 100%Control condition. After dinner desire to eat, satiety and fullness did not differ between 75%CAPS and 100%Control, while desire to eat was higher (P < 0.05) and satiety (P = 0.06) and fullness (P = 0.06) tended to be lower in the 75%Control versus 100%Control condition. Furthermore, ad libitum intake (P = 0.07) and overconsumption (P = 0.06) tended to decrease in 100%CAPS versus 100%Control. In energy balance, addition of capsaicin to the diet increases satiety and fullness, and tends to prevent overeating when food intake is ad libitum. After dinner, capsaicin prevents the effects of the negative energy balance on desire to eat.
Asunto(s)
Apetito/efectos de los fármacos , Capsaicina/farmacología , Capsicum/química , Ingestión de Energía/efectos de los fármacos , Conducta Alimentaria/efectos de los fármacos , Hiperfagia/prevención & control , Saciedad/efectos de los fármacos , Adolescente , Adulto , Dieta , Ingestión de Alimentos/efectos de los fármacos , Metabolismo Energético , Femenino , Humanos , Hambre , Masculino , Comidas , Persona de Mediana Edad , Obesidad/prevención & control , Respuesta de Saciedad/efectos de los fármacos , Sensación , Método Simple Ciego , Adulto JovenRESUMEN
Maintaining the level of daily energy expenditure during weight loss and weight maintenance is as important as maintaining satiety while decreasing energy intake. In this context, different catechin- and caffeine-rich teas (CCRTs), such as green, oolong, and white teas, as well as caffeine have been proposed as tools for maintaining or enhancing energy expenditure and for increasing fat oxidation. Tea polyphenols have been proposed to counteract the decrease in metabolic rate that is usually present during weight loss. Their effects may be of particular importance during weight maintenance after weight loss. Although the thermogenic effect of CCRT has the potential to produce significant effects on these metabolic targets as well as on fat absorption and energy intake, possibly via its impact on the gut microbiota and gene expression, a clinically meaningful outcome also depends on compliance by the subjects. Limitations to this approach require further examination, including moderating factors such as genetic predisposition, habitual caffeine intake, and catechin composition and dose. Nevertheless, CCRTs may be useful agents that could help in preventing a positive energy balance and obesity.
Asunto(s)
Peso Corporal/efectos de los fármacos , Cafeína/uso terapéutico , Camellia sinensis/química , Catequina/uso terapéutico , Metabolismo Energético/efectos de los fármacos , Obesidad/dietoterapia , Té/química , Cafeína/farmacología , Catequina/farmacología , Humanos , Metabolismo de los Lípidos/efectos de los fármacos , Fitoterapia , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Polifenoles/farmacología , Polifenoles/uso terapéuticoRESUMEN
BACKGROUND: Addition of capsaicin (CAPS) to the diet has been shown to increase energy expenditure; therefore capsaicin is an interesting target for anti-obesity therapy. AIM: We investigated the 24 h effects of CAPS on energy expenditure, substrate oxidation and blood pressure during 25% negative energy balance. METHODS: Subjects underwent four 36 h sessions in a respiration chamber for measurements of energy expenditure, substrate oxidation and blood pressure. They received 100% or 75% of their daily energy requirements in the conditions '100%CAPS', '100%Control', '75%CAPS' and '75%Control'. CAPS was given at a dose of 2.56 mg (1.03 g of red chili pepper, 39,050 Scoville heat units (SHU)) with every meal. RESULTS: An induced negative energy balance of 25% was effectively a 20.5% negative energy balance due to adapting mechanisms. Diet-induced thermogenesis (DIT) and resting energy expenditure (REE) at 75%CAPS did not differ from DIT and REE at 100%Control, while at 75%Control these tended to be or were lower than at 100%Control (pâ=â0.05 and pâ=â0.02 respectively). Sleeping metabolic rate (SMR) at 75%CAPS did not differ from SMR at 100%CAPS, while SMR at 75%Control was lower than at 100%CAPS (pâ=â0.04). Fat oxidation at 75%CAPS was higher than at 100%Control (pâ=â0.03), while with 75%Control it did not differ from 100%Control. Respiratory quotient (RQ) was more decreased at 75%CAPS (pâ=â0.04) than at 75%Control (pâ=â0.05) when compared with 100%Control. Blood pressure did not differ between the four conditions. CONCLUSION: In an effectively 20.5% negative energy balance, consumption of 2.56 mg capsaicin per meal supports negative energy balance by counteracting the unfavorable negative energy balance effect of decrease in components of energy expenditure. Moreover, consumption of 2.56 mg capsaicin per meal promotes fat oxidation in negative energy balance and does not increase blood pressure significantly. TRIAL REGISTRATION: Nederlands Trial Register; registration number NTR2944.
Asunto(s)
Metabolismo Basal/efectos de los fármacos , Capsaicina/administración & dosificación , Grasas de la Dieta/metabolismo , Metabolismo Energético/efectos de los fármacos , Consumo de Oxígeno/efectos de los fármacos , Administración Oral , Adolescente , Adulto , Presión Sanguínea/efectos de los fármacos , Composición Corporal , Estudios Cruzados , Carbohidratos de la Dieta/metabolismo , Proteínas en la Dieta/metabolismo , Metabolismo Energético/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oxidación-Reducción/efectos de los fármacos , Consumo de Oxígeno/fisiologíaRESUMEN
BACKGROUND: Epidemiologic studies have shown an inverse or U-shaped relation between sleep duration and body mass index (BMI; in kg/m(2)). Moreover, associations between energy balance (EB) and characteristics of quality sleep (QS) have recently been reported. OBJECTIVE: We assessed the relation between total energy expenditure (TEE) as well as substrate oxidation and QS after disturbed compared with nondisturbed sleep in EB. DESIGN: Fifteen healthy men (mean ± SD BMI: 24.1 ± 1.9; age: 23.7 ± 3.5 y) were included in a randomized crossover study. TEE and substrate oxidation were measured twice for 48 h in a respiration chamber, whereas slow-wave sleep (SWS), rapid eye movement (REM)-sleep, total sleeping time (TST), sleep stage 2 (S2), and QS [(SWS + REM) ÷ TST × 100%] were determined by using electroencephalography. During 2 nights, sleep (2330-0730) was either disturbed or nondisturbed (control). RESULTS: Positive correlations were shown for TEE, activity-induced energy expenditure corrected for body mass (AEE/BM), respiratory quotient (RQ), and carbohydrate oxidation with QS and SWS during nondisturbed sleep. Fat oxidation was inversely correlated with QS and SWS. RQ and carbohydrate oxidation were inversely related to REM sleep. During the disturbed condition SWS, REM, TST, and S2 were reduced, and positive correlations were shown between TEE and AEE/BM with QS. The reduction in QS was stronger in high-quality sleepers; QS reduction was positively associated with increases in energy intake, TEE, and EB. CONCLUSION: A disadvantageous shift in energy balance is primarily expressed in high-quality sleepers after a decline in QS because of disturbance, implying that good sleepers are most liable to a positive energy balance because of sleep disturbance. This trial was registered at ISRCTN as NTR1919.
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Metabolismo Energético/fisiología , Sueño/fisiología , Adulto , Composición Corporal , Índice de Masa Corporal , Metabolismo de los Hidratos de Carbono , Estudios Cruzados , Electroencefalografía , Ingestión de Energía , Humanos , Metabolismo de los Lípidos , Masculino , Actividad Motora , Oxidación-Reducción , Método Simple Ciego , Sueño REM , Adulto JovenRESUMEN
The increase in obesity, including childhood obesity, has developed over the same time period as the progressive decrease in self-reported sleep duration. Since epidemiological studies showed an inverse relationship between short or disturbed sleep and obesity, the question arose, how sleep duration and sleep quality are associated with the development of obesity. In this review, the current literature on these topics has been evaluated. During puberty, changes in body mass index (BMI) are inversely correlated to changes in sleep duration. During adulthood, this relationship remains and at the same time unfavorable metabolic and neuro-endocrinological changes develop, that promote a positive energy balance, coinciding with sleep disturbance. Furthermore, during excessive weight loss BMI and fat mass decrease, in parallel, and related with an increase in sleep duration. In order to shed light on the association between sleep duration, sleep quality and obesity, until now it only has been shown that diet-induced body-weight loss and successive body-weight maintenance contribute to sleep improvement. It remains to be demonstrated whether body-weight management and body composition improve during an intervention concomitantly with spontaneous sleep improvement compared with the same intervention without spontaneous sleep improvement.
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Peso Corporal/fisiología , Obesidad/complicaciones , Trastornos del Sueño-Vigilia/etiología , Sueño/fisiología , Discapacidades del Desarrollo/fisiopatología , HumanosRESUMEN
In addition to short sleep duration, reduced sleep quality is also associated with appetite control. The present study examined the effect of sleep fragmentation, independent of sleep duration, on appetite profiles and 24 h profiles of hormones involved in energy balance regulation. A total of twelve healthy male subjects (age 23 (sd 4) years, BMI 24·4 (sd 1·9) kg/m²) completed a 24 h randomised crossover study in which sleep (23.30-07.30 hours) was either fragmented or non-fragmented. Polysomnography was used to determine rapid-eye movement (REM) sleep, slow-wave sleep (SWS) and total sleep time (TST). Blood samples were taken at baseline and continued hourly for the 24 h period to measure glucose, insulin, ghrelin, leptin, glucagon-like peptide 1 (GLP-1) and melatonin concentrations. In addition, salivary cortisol levels were measured. Visual analogue scales were used to score appetite-related feelings. Sleep fragmentation resulted in reduced REM sleep (69·4 min compared with 83·5 min; P< 0·05) and preservation of SWS without changes in TST. In fragmented v. non-fragmented sleep, glucose concentrations did not change, while insulin secretion was decreased in the morning, and increased in the afternoon (P< 0·05), and GLP-1 concentrations and fullness scores were lower (P< 0·05). After dinner, desire-to-eat ratings were higher after fragmented sleep (P< 0·05). A single night of fragmented sleep, resulting in reduced REM sleep, induced a shift in insulin concentrations, from being lower in the morning and higher in the afternoon, while GLP-1 concentrations and fullness scores were decreased. These results may lead to increased food intake and snacking, thus contributing to a positive energy balance.
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Apetito/fisiología , Privación de Sueño/sangre , Sueño/fisiología , Adulto , Regulación del Apetito , Glucemia/análisis , Ingestión de Alimentos , Metabolismo Energético , Ghrelina/sangre , Péptido 1 Similar al Glucagón/sangre , Voluntarios Sanos , Hormonas/sangre , Humanos , Hidrocortisona/sangre , Insulina/sangre , Insulina/metabolismo , Secreción de Insulina , Leptina/sangre , Masculino , Melatonina/sangre , Polisomnografía , Sueño REM/fisiología , Encuestas y Cuestionarios , Factores de Tiempo , Adulto JovenRESUMEN
BACKGROUND: Epidemiologic studies show an inverse or U-shaped relation between sleep duration and BMI. Decreases in total energy expenditure (TEE) and physical activity have been suggested to be contributing factors. OBJECTIVE: The objective was to assess the effect of sleep fragmentation on energy metabolism and energy balance in healthy men. DESIGN: Fifteen healthy male subjects [mean ± SD BMI (in kg/m(2)): 24.1 ± 1.9; age: 23.7 ± 3.5 y] were included in a randomized crossover study in which energy expenditure, substrate oxidation, and physical activity (by radar) were measured twice for 48 h in a respiration chamber while subjects were monitored by electroencephalography to determine slow-wave sleep (SWS), rapid eye movement (REM) sleep, and total sleeping time (TST). During 2 nights, sleep (2330-0730 h) was either fragmented or nonfragmented. RESULTS: Fragmented sleep led to reductions in TST, SWS, and REM sleep (P < 0.001). TEE did not differ (9.96 ± 0.17 compared with 9.83 ± 0.13 MJ/d, NS) between the sleep groups, nor did the components of energy expenditure, with the exception of activity-induced energy expenditure (AEE; 1.63 ± 0.15 compared with 1.42 ± 0.13 MJ/d for fragmented and nonfragmented sleep, respectively; P < 0.05). Physical activity, exhaustion, sleepiness, respiratory quotient (RQ), and carbohydrate oxidation were elevated in comparison with nonfragmented sleep [physical activity counts: 2371 ± 118 compared with 2204 ± 124 counts/d, P < 0.02; exhaustion: 40.1 ± 3.8 compared with 21.8 ± 2.4 mm (by using a visual analog scale; VAS), P < 0.001; sleepiness: 47.4 ± 4.2 compared with 33.9 ± 4.6 mm (VAS), P < 0.001; RQ: 0.94 ± 0.04 compared with 0.91 ± 0.03, P < 0.05; and carbohydrate oxidation: 346.3 ± 23.8 compared with 323.7 ± 22.5 g/d, P < 0.05], whereas fat oxidation was reduced (29.1 ± 9.1 compared with 61.0 ± 6.6 g/d, P < 0.01). CONCLUSIONS: Fragmented compared with nonfragmented sleep induced reductions in the most important sleep phases, which coincided with elevated AEE, physical activity, exhaustion, and sleepiness. RQ and carbohydrate oxidation increased and fat oxidation decreased, which may predispose to overweight. This trial is registered at www.who.int/ictrp and www.trialregister.nl as NTR1919.
Asunto(s)
Metabolismo de los Hidratos de Carbono , Metabolismo Energético , Fatiga , Metabolismo de los Lípidos , Esfuerzo Físico/fisiología , Privación de Sueño/fisiopatología , Sueño/fisiología , Adulto , Dióxido de Carbono/metabolismo , Estudios Cruzados , Electroencefalografía , Humanos , Masculino , Oxidación-Reducción , Consumo de Oxígeno , Dimensión del Dolor , Valores de Referencia , Privación de Sueño/metabolismo , Vigilia , Adulto JovenRESUMEN
Green tea and protein separately are able to increase diet-induced thermogenesis. Although their effects on long-term weight-maintenance were present separately, they were not additive. Therefore, the effect of milk-protein (MP) in combination with green tea on diet-induced thermogenesis (DIT) was examined in 18 subjects (aged 18-60 years; BMI: 23.0 ± 2.1 kg/m(2)). They participated in an experiment with a randomized, 6 arms, crossover design, where energy expenditure and respiratory quotient (RQ) were measured. Green tea (GT)vs. placebo (PL) capsules were either given in combination with water or with breakfasts containing milk protein in two different dosages: 15 g (15 MP) (energy% P/C/F: 15/47/38; 1.7 MJ/500 mL), and 3.5 g (3.5 MP) (energy% P/C/F: 41/59/0; 146.4 kJ/100 mL). After measuring resting energy expenditure (REE) for 30 min, diet-induced energy expenditure was measured for another 3.5 h after the intervention. There was an overall significant difference observed between conditions (p < 0.001). Post-hoc, areas under the curve (AUCs) for diet-induced energy expenditure were significantly different (P ≤ 0.001) for GT + water (41.11 [91.72] kJ·3.5 h) vs. PL + water (10.86 [28.13] kJ·3.5 h), GT + 3.5 MP (10.14 [54.59] kJ·3.5 h) and PL + 3.5 MP (12.03 [34.09] kJ·3.5 h), but not between GT + 3.5 MP, PL + 3.5 MP and PL + water, indicating that MP inhibited DIT following GT. DIT after GT + 15 MP (167.69 [141.56] kJ·3.5 h) and PL + 15 MP (168.99 [186.56] kJ·3.5 h) was significantly increased vs. PL + water (P < 0.001), but these were not different from each other indicating that 15 g MP stimulated DIT, but inhibited the GT effect on DIT. No significant differences in RQ were seen between conditions for baseline and post-treatment. In conclusion, consumption of milk-protein inhibits the effect of green tea on DIT.
Asunto(s)
Dieta , Proteínas de la Leche/administración & dosificación , Té , Termogénesis/fisiología , Adolescente , Adulto , Estudios Cruzados , Proteínas en la Dieta/administración & dosificación , Metabolismo Energético/efectos de los fármacos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Placebos , Método Simple Ciego , Té/química , Termogénesis/efectos de los fármacosRESUMEN
Previous studies have shown effects of high-protein diets, especially whey protein, on energy expenditure and satiety, yet a possible distinction between the effects of whey or alpha-lactalbumin has not been made. The present study assessed the effects of the addition of total whey protein (whey) or caseinomacropeptide-depleted alpha-lactalbumin-enriched whey protein (alpha-lac) to a breakfast yoghurt drink on energy expenditure and appetite suppression in human subjects. A total of eighteen females and seventeen males (aged 20.9 (sd 1.9) years; BMI 23.0 (sd 2.1) kg/m2) participated in an experiment with a randomised, three-arm, cross-over design where diet-induced energy expenditure, respiratory quotient and satiety were measured. Breakfasts were isoenergetic and subject-specific: a normal-protein (NP) breakfast consisting of whole milk (15, 47 and 38 % energy from protein, carbohydrate and fat, respectively), a high-protein (HP) breakfast with additional whey or a HP breakfast containing alpha-lac (41, 47 and 12 % energy from protein, carbohydrate and fat, respectively). Resting energy expenditure did not differ between the three conditions. HP breakfasts (area under the curve: whey, 217.1 (se 10.0) kJ x 4 h; alpha-lac, 234.3 (se 11.6) kJ x 4 h; P < 0.05) increased diet-induced thermogenesis more compared with a NP yoghurt at breakfast (179.7 (se 10.9) kJ x 4 h; P < 0.05). Hunger and desire to eat were significantly more suppressed after alpha-lac (hunger, - 6627 (se 823); desire to eat, - 6750 (se 805) mm visual analogue scale (VAS) x 4 h; P < 0.05) than after the whey HP breakfast (hunger, - 5448 (se 913); desire to eat, - 5070 (se 873) mm VAS x 4 h; P < 0.05). After the HP breakfasts, a positive protein balance occurred (alpha-lac, 0.35 (sd 0.18) MJ/4 h; whey, 0.37 (sd 0.20) MJ/4 h; P < 0.001); after the NP breakfast a positive fat balance occurred (1.03 (sd 0.29) MJ/4 h; P < 0.001). In conclusion, consumption of a breakfast yoghurt drink with added whey or alpha-lac increased energy expenditure, protein balance and decreased fat balance compared with a NP breakfast. The alpha-lac-enriched yoghurt drink suppressed hunger and the desire to eat more than the whey-enriched yoghurt drink.
Asunto(s)
Regulación del Apetito/efectos de los fármacos , Apetito/efectos de los fármacos , Proteínas en la Dieta/farmacología , Lactalbúmina/farmacología , Proteínas de la Leche/farmacología , Termogénesis/efectos de los fármacos , Yogur , Adolescente , Adulto , Área Bajo la Curva , Bebidas , Caseínas/farmacología , Estudios Cruzados , Dieta , Proteínas en la Dieta/metabolismo , Suplementos Dietéticos , Metabolismo Energético/efectos de los fármacos , Femenino , Alimentos Fortificados , Humanos , Hambre/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Masculino , Fragmentos de Péptidos/farmacología , Método Simple Ciego , Proteína de Suero de Leche , Adulto JovenRESUMEN
BACKGROUND: Green tea (epigallocatechin gallate + caffeine) and protein each were shown to improve body weight maintenance after weight loss. OBJECTIVE: We investigated the effect of a green tea-caffeine mixture added to a high-protein (HP) diet on weight maintenance (WM) after body weight loss in moderately obese subjects. DESIGN: A randomized, placebo-controlled, double-blind parallel trial was conducted in 80 overweight and moderately obese subjects [age (mean +/- SD): 44 +/- 2 y; body mass index (BMI; in kg/m(2)): 29.6 +/- 2.0] matched for sex, age, BMI, height, body mass, and with a habitually low caffeine intake. A very-low-energy diet intervention during 4 wk was followed by 3 mo of WM; during the WM period, the subjects received a green tea-caffeine mixture (270 mg epigallocatechin gallate + 150 mg caffeine/d) or placebo, both in addition to an adequate protein (AP) diet (50-60 g protein/d) or an HP diet (100-120 g protein/d). RESULTS: Subjects lost 7.0 +/- 1.6 kg, or 8.2 +/- 2.0%, body weight (P < 0.001). During the WM phase, WM, resting energy expenditure, and fat-free mass (FFM) increased relatively in both the HP groups and in the AP + green tea-caffeine mixture group (P < 0.05), whereas respiratory quotient and body fat mass decreased, all compared with the AP + placebo group. Satiety increased only in both HP groups (P < 0.05). The green tea-caffeine mixture was only effective with the AP diet. CONCLUSION: The green tea-caffeine mixture, as well as the HP diet, improved WM independently through thermogenesis, fat oxidation, sparing FFM, and, for the HP diet, satiety; a possible synergistic effect failed to appear.