RESUMO
Dairy product consumption may decrease colorectal cancer (CRC) risk, but very few studies have evaluated the association between different types of dairy products and CRC location. The aim of this systematic review and meta-analysis was to examine the associations between dairy product consumption and CRC incidence. Summary RRs and ORs with 95% CIs were estimated. A total of 15 cohort studies and 14 case-control studies comprising a total of >22,000 cases were included in the quantitative synthesis. The cohort studies showed a consistent significant decrease in CRC risk associated with higher consumption of total dairy products (RR: 0.80; 95% CI: 0.70, 0.91) and total milk (RR: 0.82; 95% CI: 0.76, 0.88) compared with the CRC risk associated with lower consumption. These studies also showed a significant protective association between low-fat milk consumption and CRC (RR: 0.76; 95% CI: 0.66, 0.88), but only for colon cancer (RR: 0.73; 95% CI: 0.61, 0.87). Cheese consumption was inversely associated with the risk of CRC (RR: 0.85; 95% CI: 0.76, 0.96) and proximal colon cancer (RR: 0.74; 95% CI: 0.60, 0.91). No significant associations with CRC were found for the consumption of low-fat dairy products, whole milk, fermented dairy products, or cultured milk. Most of these associations were not supported by the case-control studies. In conclusion, high consumption of total dairy products and total milk was associated with a lower risk of developing CRC at any anatomic location, including the proximal and distal colon and the rectum. Low-fat milk consumption was associated with a lower risk of CRC, but this association was restricted to colon cancer. Cheese consumption was associated with the prevention of CRC, specifically proximal colon cancer. Further studies on larger samples and with longer follow-up periods, along with appropriately designed and executed clinical trials, are warranted to determine whether dairy product consumption affects CRC development.
Assuntos
Neoplasias Colorretais/prevenção & controle , Laticínios , Dieta , Comportamento Alimentar , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Gorduras na Dieta/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Leite , Adulto JovemRESUMO
There is limited evidence from epidemiological studies for the inflammatory or anti-inflammatory properties of fatty acids in blood cell membranes. Therefore, this study examined associations between baseline (n = 282) and 1-year (n = 143) changes in the levels of fatty acids in blood cell membranes with circulating inflammatory markers in older adults at high cardiovascular risk. The data for this cross-sectional analysis was obtained from a case-control study within the PREDIMED study. Linear regression with elastic net penalty was applied to test associations between measured fatty acids and inflammatory markers. Several fatty acids were associated with interferon-γ (IFNγ) and interleukins (ILs) IL-6, IL-8, and IL-10 at baseline and additionally also with IL-1b at 1 year. Omega-6 fatty acids were consistently positively associated with pro-inflammatory IL-6 and IL-8 at baseline. Omega-3 fatty acids including C20:5n3 and C18:3n3 were negatively associated with IFN-γ at 1 year. It is interesting to note that the cis and trans forms of C16:1n7 at 1 year were oppositely associated with the inflammatory markers. C16:1n7trans was negatively associated with IFN-γ, IL-6, IL-8, IL-10, and IL-1b, whereas C16:1n7cis was positively associated with IL-1b. This study adds to the growing body of evidence suggesting potential differences in inflammatory or anti-inflammatory properties of fatty acids in blood cell membranes.
Assuntos
Células Sanguíneas/citologia , Membrana Celular/química , Ácidos Graxos/análise , Inflamação/metabolismo , Idoso , Idoso de 80 Anos ou mais , Células Sanguíneas/química , Estudos de Casos e Controles , Estudos Transversais , Citocinas/análise , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
AIMS: We aimed to examine the associations of leisure-time physical activity (PA) and sedentary behavior (SB) with the prevalence of sarcopenia, body composition and muscle strength among older adults having overweight/obesity and metabolic syndrome, from the PREDIMED-Plus trial. METHODS: Cross-sectional baseline analysis including 1539 men and women (65 ± 5 y). Sarcopenia was defined as low muscle mass (according to FNIH cut-offs) plus low muscle strength (lowest sex-specific tertile for 30-s chair-stand test). We applied multivariable-adjusted Cox regression with robust variance and constant time (given the cross-sectional design) for the associations of self-reported leisure-time PA and SB with sarcopenia; and multivariable-linear regression for the associations with dual-energy X-ray absorptiometry (DXA)-derived bone mass, fat mass, lean mass and lower-limb muscle strength. RESULTS: Inverse associations were observed between sarcopenia and each hourly increment in total [prevalence ratio 0.81 (95% confidence interval, 0.70, 0.93)], moderate [0.80 (0.66, 0.97)], vigorous [0.51 (0.32, 0.84)], and moderate-vigorous PA (MVPA) [0.74 (0.62, 0.89)]. Incrementing 1-h/day total-PA and MVPA was inversely associated with body-mass-index, waist circumference (WC), fat mass, and positively associated with bone mass and lower-limb muscle strength (all P <.05). One h/day increase in total SB, screen-based SB and TV-viewing was positively associated with body-mass-index, WC and fat mass. Light-PA was not significantly associated with any outcome. CONCLUSIONS: Total-PA and PA at moderate and high intensities may protect against the prevalence of sarcopenia, have a beneficial role on body composition and prevent loss of muscle strength. SB, particularly TV-viewing, may have detrimental effects on body composition in older adults at high cardiovascular risk.
Assuntos
Composição Corporal/fisiologia , Exercício Físico/fisiologia , Atividades de Lazer , Síndrome Metabólica/epidemiologia , Força Muscular/fisiologia , Obesidade/epidemiologia , Sarcopenia/epidemiologia , Idoso , Comorbidade , Estudos Transversais , Feminino , Humanos , Masculino , Ilhas do Mediterrâneo/epidemiologia , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Prevalência , Sarcopenia/fisiopatologiaRESUMO
BACKGROUND: Visceral adipose tissue (VAT) is a strong predictor of cardiometabolic health, and lifestyle factors may have a positive influence on VAT depot. This study aimed to assess the cross-sectional associations between baseline levels of physical activity (PA), sedentary behaviours (SB) and adherence to the Mediterranean diet (MedDiet) with VAT depot in older individuals with overweight/obesity and metabolic syndrome. METHODS: Baseline data of the PREDIMED-Plus study including a sample of 1,231 Caucasian men and women aged 55-75 years were used. Levels of leisure-time PA (total, light, and moderate-to-vigorous, in METs·min/day) and SB (total and TV-viewing, in h/day) were evaluated using validated questionnaires. Adherence to the MedDiet was evaluated using a 17-item energy-restricted MedDiet (erMedDiet) screener. The chair-stand test was used to estimate the muscle strength. VAT depot was assessed with DXA-CoreScan. Multivariable adjusted linear regression models were used to evaluate the association between lifestyle factors and VAT. For the statistics we had used multiadjusted linear regression models. RESULTS: Total leisure-time PA (100 METs·min/day: ß -24.3g, -36.7;-11.9g), moderate-to-vigorous PA (ß -27.8g, 95% CI -40.8;-14.8g), chair-stand test (repeat: ß -11.5g, 95% CI -20.1;-2.93g) were inversely associated, and total SB (h/day: ß 38.2g, 95% CI 14.7;61.7) positively associated with VAT. Light PA, TV-viewing time and adherence to an erMedDiet were not significantly associated with VAT. CONCLUSIONS: In older adults with overweigh/obesity and metabolic syndrome, greater PA, muscle strength, and lower total SB were associated with less VAT depot. In this study, adherence to an erMedDiet was not associated with lower VAT.
Assuntos
Gordura Intra-Abdominal , Estilo de Vida , Acidente Vascular Cerebral/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
BACKGROUND: Sarcopenia is a progressive age-related skeletal muscle disorder associated with increased likelihood of adverse outcomes. Muscle wasting is often accompanied by an increase in body fat, leading to 'sarcopenic obesity'. The aim of the present study was to analyse the association of lifestyle variables such as diet, dietary components, physical activity (PA), body composition, and inflammatory markers, with the risk of sarcopenic obesity. METHODS: A cross-sectional analysis based on baseline data from the PREDIMED-Plus study was performed. A total of 1535 participants (48% women) with overweight/obesity (body mass index: 32.5 ± 3.3 kg/m2 ; age: 65.2 ± 4.9 years old) and metabolic syndrome were categorized according to sex-specific tertiles (T) of the sarcopenic index (SI) as assessed by dual-energy X-ray absorptiometry scanning. Anthropometrical measurements, biochemical markers, dietary intake, and PA information were collected. Linear regression analyses were carried out to evaluate the association between variables. RESULTS: Subjects in the first SI tertile were older, less physically active, showed higher frequency of abdominal obesity and diabetes, and consumed higher saturated fat and less vitamin C than subjects from the other two tertiles (all P < 0.05). Multiple adjusted linear regression models evidenced significant positive associations across tertiles of SI with adherence to the Mediterranean dietary score (P-trend < 0.05), PA (P-trend < 0.0001), and the 30 s chair stand test (P-trend < 0.0001), whereas significant negative associations were found with an inadequate vitamin C consumption (P-trend < 0.05), visceral fat and leucocyte count (all P-trend < 0.0001), and some white cell subtypes (neutrophils and monocytes), neutrophil-to-lymphocyte ratio, and platelet count (all P-trend < 0.05). When models were additionally adjusted by potential mediators (inflammatory markers, diabetes, and waist circumference), no relevant changes were observed, only dietary variables lost significance. CONCLUSIONS: Diet and PA are important regulatory mediators of systemic inflammation, which is directly involved in the sarcopenic process. A healthy dietary pattern combined with exercise is a promising strategy to limit age-related sarcopenia.
Assuntos
Inflamação/complicações , Estilo de Vida , Obesidade/epidemiologia , Obesidade/etiologia , Sarcopenia/epidemiologia , Sarcopenia/etiologia , Absorciometria de Fóton , Idoso , Biomarcadores , Composição Corporal , Estudos Transversais , Suscetibilidade a Doenças , Feminino , Humanos , Inflamação/metabolismo , Masculino , Pessoa de Meia-Idade , Obesidade/diagnóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , Sarcopenia/diagnóstico , Fatores SocioeconômicosRESUMO
Magnesium (Mg) is an essential dietary element for humans involved in key biological processes. A growing body of evidence from epidemiological studies, randomized controlled trials (RCTs) and meta-analyses have indicated inverse associations between Mg intake and cardiovascular diseases (CVD). The present review aims to summarize recent scientific evidence on the topic, with a focus on data from epidemiological studies assessing the associations between Mg intake and major cardiovascular (CV) risk factors and CVD. We also aimed to review current literature on circulating Mg and CVD, as well as potential biological processes underlying these observations. We concluded that high Mg intake is associated with lower risk of major CV risk factors (mainly metabolic syndrome, diabetes and hypertension), stroke and total CVD. Higher levels of circulating Mg are associated with lower risk of CVD, mainly ischemic heart disease and coronary heart disease. Further, RCTs and prospective studies would help to clarify whether Mg intake and Mg circulating levels may also protect against other CVDs and CVD death.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Magnésio/farmacologia , Doenças Cardiovasculares/epidemiologia , Dieta , Suplementos Nutricionais , Humanos , Magnésio/administração & dosagem , Fatores de RiscoRESUMO
Infertility, which affects â¼15% of the world's population, is a global public health issue recognized by the WHO. Therefore, it is of major clinical and public health importance to investigate whether modifiable lifestyle factors-such as stress, drug use, smoking, alcohol intake, and diet-may influence human fertility. A systematic review and meta-analysis of randomized clinical trials (RCTs) from the MEDLINE-PubMed database was conducted to assess the effect of nutrients, dietary supplements, or food on sperm quality parameters. In total, 28 articles were included for qualitative analysis and 15 for quantitative meta-analysis. Total sperm concentrations [expressed as mean differences (MDs); 95% CIs, in spermatozoa (spz)/mL] were increased by selenium (3.91 × 106 spz/mL; 3.08, 4.73 spz/mL), zinc (1.48 × 106 spz/mL; 0.69, 2.27 spz/mL), omega-3 (n-3) fatty acids (10.98 × 106 spz/mL; 10.25, 11.72 spz/mL), and coenzyme Q10 (CoQ10) (5.93 × 106 spz/mL; 5.36, 6.51 spz/mL). Sperm counts were increased by ω-3 fatty acids (18.70 × 106 spz/mL; 16.89, 20.51 spz/mL) and CoQ10 supplementation (10.15 × 106 spz/mL; 8.34, 11.97 spz/mL). Sperm total motility was increased by selenium (3.30%; 2.95%, 3.65%), zinc (7.03%; 6.03%, 8.03%), ω-3 fatty acids (7.55%; 7.09%, 8.01%), CoQ10 (5.30%; 4.98%, 5.62%), and carnitines (7.84%; 6.54%, 9.13%), whereas sperm progressive motility was increased only after supplementation with carnitines (7.45%; 6.24%, 8.67%). Finally, sperm morphology was enhanced by selenium (1.87%; 1.50%, 2.24%), ω-3 fatty acid (0.91%; 0.69%, 1.13%), CoQ10 (1.06%; 0.72%, 1.41%), and carnitine (4.91%; 3.68%, 6.15%) supplementation. This meta-analysis of RCTs suggests that some dietary supplements could beneficially modulate sperm quality parameters and affect male fertility. However, results must be cautiously interpreted due to the limited sample size of the meta-analyzed studies and the considerable observed interstudy heterogeneity.The present study and the corresponding search protocol were registered at the PROSPERO registry at http://www.crd.york.ac.uk/PROSPERO as CRD42017058380.
Assuntos
Suplementos Nutricionais , Infertilidade Masculina/terapia , Nutrientes/farmacologia , Espermatozoides/efeitos dos fármacos , Adulto , Humanos , Masculino , Ensaios Clínicos Controlados Aleatórios como Assunto , Contagem de Espermatozoides , Motilidade dos Espermatozoides/efeitos dos fármacosRESUMO
Background: High glucose and insulin concentrations seem to have a negative impact on bone health. However, the relation between the dietary glycemic index (DGI) and the dietary glycemic load (DGL), which has proved to be effective at modulating blood glucose concentrations after carbohydrate consumption, has yet to be explored in relation to bone health. Objective: The aim of the study was to examine the associations between the DGI or DGL and the risk of osteoporotic-related fractures in an elderly Mediterranean population. Design: The study was conducted in 870 subjects aged 55-80 y at high cardiovascular disease risk participating in the PREvención con DIeta MEDiterránea (PREDIMED)-Reus study. The DGI and DGL were estimated from validated food-frequency questionnaires with the use of the international glycemic index and glycemic load values, with glucose as reference. Data on osteoporotic fractures were acquired from a systematic review of medical records. We used Cox proportional hazard models to assess the risk of osteoporotic fracture according to tertiles of average DGI and DGL. Results: A total of 114 new cases of osteoporotic-related fractures were documented after a mean follow-up of 8.9 y. Participants in the highest tertile of DGI and DGL had a significantly higher risk of osteoporotic fractures than those in the lowest tertile after adjusting for potential confounders (HR: 1.80; 95% CI: 1.03, 3.15 and HR: 3.20; 95% CI: 1.25, 8.18, respectively). Conclusions: A high DGI and DGL are associated with a higher risk of osteoporosis-related fractures in an elderly Mediterranean population at high cardiovascular disease risk. This trial was registered at isrctn.com as ISRCTN35739639.
Assuntos
Dieta com Restrição de Gorduras , Dieta Mediterrânea , Índice Glicêmico , Carga Glicêmica , Fraturas por Osteoporose/etiologia , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/epidemiologia , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
BACKGROUND & AIMS: Legumes, a low-energy, nutrient-dense and low glycemic index food, have shown beneficial effects on glycemic control and adiposity. As such, legumes are widely recommended in diabetic diets, even though there is little evidence that their consumption protects against type 2 diabetes. Therefore the aim of the present study was to examine the associations between consumption of total legumes and specific subtypes, and type 2 diabetes risk. We also investigated the effect of theoretically substituting legumes for other protein- or carbohydrate-rich foods. METHODS: Prospective assessment of 3349 participants in the PREvención con DIeta MEDiterránea (PREDIMED) study without type 2 diabetes at baseline. Dietary information was assessed at baseline and yearly during follow-up. We used Cox regression models to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for type-2 diabetes incidence according to quartiles of cumulative average consumption of total legumes, lentils, chickpeas, dry beans and fresh peas. RESULTS: During a median follow-up of 4.3 years, 266 new cases of type 2 diabetes occurred. Individuals in the highest quartile of total legume and lentil consumption had a lower risk of diabetes than those in the lowest quartile (HR: 0.65; 95% CI: 0.43, 0.96; P-trend = 0.04; and HR: 0.67; 95% CI: 0.46-0.98; P-trend = 0.05, respectively). A borderline significant association was also observed for chickpeas consumption (HR 0.68; 95% CI: 0.46, 1.00; P-trend = 0.06). Substitutions of half a serving/day of legumes for similar servings of eggs, bread, rice or baked potato was associated with lower risk of diabetes incidence. CONCLUSIONS: A frequent consumption of legumes, particularly lentils, in the context of a Mediterranean diet, may provide benefits on type 2 diabetes prevention in older adults at high cardiovascular risk. TRIAL REGISTRATION: The trial is registered at http://www.controlled-trials.com (ISRCTN35739639). Registration date: 5th October 2005.
Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/prevenção & controle , Dieta Mediterrânea , Dieta , Fabaceae , Adiposidade , Idoso , Glicemia/análise , Feminino , Seguimentos , Índice Glicêmico , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de RiscoRESUMO
Study Objectives: To examine independent and combined associations of sleep duration and sleep variability with body composition, obesity and type 2 diabetes (T2D) in elders at high cardiovascular risk. Methods: Cross-sectional analysis of 1986 community-dwelling elders with overweight/obesity and metabolic syndrome from PREDIMED-Plus trial. Associations of accelerometry-derived sleep duration and sleep variability with body mass index (BMI), waist circumference (WC) and body composition were assessed fitting multivariable-adjusted linear regression models. Prevalence ratios (PR) and 95% confidence intervals (CI) for obesity and T2D were obtained using multivariable-adjusted Cox regression with constant time. "Bad sleepers" (age-specific non-recommended sleep duration plus sleep variability above the median) and "good sleepers" (age-specific recommended sleep duration plus sleep variability below the median) were characterized by combining sleep duration and sleep variability, and their associations with these outcomes were examined. Results: One hour/night increment in sleep duration was inversely associated with BMI (ß -0.38 kg/m2 [95% CI -0.54, -0.23]), WC (ß -0.86 cm [95% CI -1.25, -0.47]), obesity (PR 0.96 [95% CI 0.93, 0.98]), T2D (PR 0.93 [95% CI 0.88, 0.98]) and other DXA-derived adiposity-related measurements (android fat and trunk fat, all p < .05). Each 1-hour increment in sleep variability was positively associated with T2D (PR 1.14 [95% CI 1.01, 1.28]). Compared with "good sleepers," "bad sleepers" were positively associated with obesity (PR 1.12 [95% CI 1.01, 1.24]) and T2D (PR 1.62 [95% CI 1.28, 2.06]). Conclusions: This study revealed cross-sectional associations of sleep duration with adiposity parameters and obesity. Sleep duration and sleep variability were associated with T2D. Considering simultaneously sleep duration and sleep variability could have additional value, particularly for T2D, as they may act synergistically.
Assuntos
Adiposidade/fisiologia , Diabetes Mellitus Tipo 2/fisiopatologia , Obesidade/fisiopatologia , Distúrbios do Início e da Manutenção do Sono/fisiopatologia , Sono/fisiologia , Acelerometria , Idoso , Índice de Massa Corporal , Estudos Transversais , Feminino , Humanos , Masculino , Síndrome Metabólica/patologia , Pessoa de Meia-Idade , Fatores de Risco , Circunferência da CinturaRESUMO
Limited data exists on the interrelationships between physical activity (PA), sedentary behaviors and sleep concerning cardiometabolic risk factors in aged adults at high cardiovascular disease risk. Our aim was to examine independent and joint associations between time spent in leisure-time PA, sedentary behaviors and sleep on the prevalence of obesity, type 2 diabetes (T2D) and components of the metabolic syndrome (MetS) in Mediterranean individuals at high cardiovascular risk. Cross-sectional analyses were performed on baseline data from 5776 Spanish adults (aged 55-75y in men; 60-75y in women) with overweight/obesity and MetS, from October 2013 to October 2016, in the PREDIMED-PLUS trial. Employing multivariable-adjusted Cox regression with robust variance and constant time (given the cross-sectional design), higher prevalence of obesity, T2D and abdominal obesity as component of the MetS were associated with greater time in TV-viewing (Relative Risk, RR: 1.02, 95%CI: 1.01, 1.03; RR:1.04, 95%CI: 1.02, 1.06 and RR: 1.01 95%CI: 1.00, 1.02; respectively, all P < .01). Conversely, greater time in moderate-vigorous PA (MVPA) was associated with lower prevalence of obesity, T2D, abdominal obesity and low HDL-cholesterol (RR: 0.95, 95%CI: 0.93, 0.97; RR: 0.94, 95%CI: 0.89, 0.99; RR: 0.97, 95%CI: 0.96, 0.98; and RR: 0.95, 95%CI: 0.91, 0.99, respectively, all P < .05). For these outcomes, theoretically substituting 1-h/day of MVPA for 1-h/day TV-viewing was also significantly associated with lower prevalence (RR 0.91 to 0.97, all P < .05). Similar lower RR in these outcomes was observed when substituting 1-h/day of MVPA for 1-h/day of sleeping. Longer time watching TV and not meeting MVPA recommendations were jointly associated with higher RR of the prevalence of obesity and T2D. We concluded that, in senior individuals at high cardiovascular risk, greater time spent on MVPA and fewer on sedentary behaviors was inversely associated with prevalence of obesity, T2D, and some of the components of MetS.
Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/etiologia , Exercício Físico , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/etiologia , Comportamento Sedentário , Sono , Idoso , Biomarcadores , Doenças Cardiovasculares/complicações , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Fatores de Risco , Espanha/epidemiologiaRESUMO
BACKGROUND: Sleep has been associated with the regulation of energy balance, yet the relation between sleep stages and energy expenditure remains unclear. OBJECTIVE: The objective was to investigate the relation between sleep stages and energy expenditure, with sleep stage and overnight energy expenditure patterns taken into account. DESIGN: Thirteen subjects aged (mean ± SD) 24.3 ± 2.5 y with a BMI (in kg/m(2)) of 23.6 ± 1.7 slept in a respiration chamber while sleep was polysomnographically recorded to determine wake after sleep onset (WASO), slow-wave sleep (SWS), and rapid eye movement (REM) sleep. Energy expenditure was calculated during each sleep stage for the whole night and separately for sleeping metabolic rate (SMR; ie, 3-h period during the night with the lowest mean energy expenditure) and non-SMR. RESULTS: Energy expenditure and sleep stages showed characteristic patterns during the night, independently of each other. Sleep stages exerted no effect on energy expenditure during the whole night, except for WASO compared with SWS (P < 0.05) and WASO compared with REM sleep (P < 0.05). During the SMR and non-SMR periods of the night, no overall effect of sleep stage on energy expenditure, except for WASO compared with SWS (P < 0.05) and WASO compared with REM sleep (P < 0.01) during the non-SMR period of the night, was found. Energy expenditure and activity counts during the night were positively correlated (r = 0.927, P < 0.001). CONCLUSIONS: Energy expenditure does not vary according to sleep stage overnight, except for higher energy expenditure during wake episodes than during SWS and REM sleep. Coincidence of the sleep stage pattern and the overnight energy expenditure pattern may have caused accidental relations in previous observations. This trial was registered at http://apps.who.int/trialsearch as NTR2926.