Total daily energy expenditure (“total expenditure”) reflects daily energy needs and is a critical variable in human health and physiology, but its trajectory over the life course is poorly studied. We analyzed a large, diverse database of total expenditure measured by the doubly labeled water method for males and females aged 8 days to 95 years. Total expenditure increased with fat-free mass in a power-law manner, with four distinct life stages. Fat-free mass–adjusted expenditure accelerates rapidly in neonates to ~50% above adult values at ~1 year; declines slowly to adult levels by ~20 years; remains stable in adulthood (20 to 60 years), even during pregnancy; then declines in older adults. These changes shed light on human development and aging and should help shape nutrition and health strategies across the life span.

We examined the effect of curcumin (CUR) ingestion before or after exercise on changes in muscle damage and inflammatory responses after exercise. We conducted two parallel experiments with different CUR ingestion timings using a double‐blind crossover. In Exp. 1, ten healthy men ingested 180 mg d−1 of CUR or placebo (PLA) 7 days before exercise. In Exp. 2, ten other healthy men ingested 180 mg d−1 of CUR or PLA 7 days after exercise. They performed 30 maximal isokinetic (120°s−1) eccentric contractions of the elbow flexors using an isokinetic dynamometer, and this was repeated with the other arm ≥4 weeks later. Maximal voluntary contraction (MVC) torque of the elbow flexors, elbow joint range of motion (ROM), muscle soreness, and serum creatine kinase (CK) activity were measured before, immediately after, and 1‐7 days after exercise. Plasma interleukin‐8 (IL‐8) was measured before, immediately after, 12 hours after, and 1‐7 days after exercise. The changes were compared over time. In Exp. 1, no significant differences were found between CUR and PLA subjects for each parameter. However, increases in IL‐8 were significantly reduced 12 hours after exercise when CUR was ingested before exercise. In Exp. 2, compared to the PLA subjects, MVC torque and ROM were higher 3‐7 days and 2‐7 days after exercise (P < 0.05), respectively, whereas muscle soreness and CK activity were lower 3‐6 days and 5‐7 days after exercise (P < 0.05), respectively, in CUR subjects. CUR ingestion before exercise could attenuate acute inflammation, and after exercise could attenuate muscle damage and facilitate faster recovery.

Curcumin is known to have potent anti-inflammatory effects. We have reported that acute curcumin ingestion attenuates eccentric exercise-induced muscle damage. This study aimed to examine the effect of curcumin ingestion timing (before or after exercise) on the changes in muscle damage markers after eccentric exercise. In this randomized, single-blind, parallel design study, 24 healthy young men performed 30 maximal isokinetic (120˚/s) eccentric contractions of the elbow flexors using an isokinetic dynamometer. Subjects were randomly assigned to ingest 180 mg/d of oral curcumin either 7 d before (PRE) or 4 d after exercise (POST) or 180 mg/d of oral placebo 4 d after exercise (CON). The maximal voluntary contraction (MVC) torque of the elbow flexors, elbow joint range of motion (ROM), muscle soreness, and serum creatine kinase (CK) activity were measured before, immediately after, and 1-4 d after exercise. Changes in these variables were compared over time. In the POST group, ROM were higher at 3-4 d and muscle soreness was lower at 3 d after exercise compared with the CON group (p,0.05). However, in the PRE group, there were no significant differences compared with the CON group in changes in ROM and muscle soreness. Meanwhile, there were no significant differences among the groups in terms of changes in MVC torque and serum CK activity. Our results suggest that curcumin ingestion after exercise had a more beneficial effect in attenuating muscle soreness.

Weight-classified athletes need an energy intake plan to accomplish target weight reduction. They have to consider body composition and energy metabolism during rapid weight loss followed by rapid weight regain to achieve their energy intake plan. We investigated the effects of rapid weight loss, followed by weight regain, on body composition and energy expenditure. Ten weight-classified athletes were instructed to reduce their body weight by 5% in 7 days. Following the weight loss, they were asked to try to regain all of their lost weight with an ad libitum diet for 12 h. Food intake was recorded during the baseline, weight loss, and regain periods. Fat mass, total body water, and fat-free dry solids were estimated by underwater weighing and stable isotope dilution methods. A three-component model was calculated using Siri's equation. Basal and sleeping metabolic rates were measured by indirect calorimetry. Body composition and energy expenditure were measured before and after weight loss and after weight regain. Body weight, total body water, and fat-free dry solids were decreased after the weight loss period but recovered after weight regain (p < 0.05). Basal metabolic rate did not change throughout the study. Sleeping metabolic rate decreased significantly during weight loss but recovered after weight regain. Changes in total body water greatly affect body weight during rapid weight loss and regain. In addition, rapid weight loss and regain did not greatly affect the basal metabolic rate in weight-classified athletes.

Body water content increases during carbohydrate loading because 2.7-4-g water binds each 1 g of glycogen. Bioelectrical impedance spectroscopy (BIS) allows separate assessment of extracellular and intracellular water (ECW and ICW, respectively) in the whole body and each body segment. However, BIS has not been shown to detect changes in body water induced by carbohydrate loading. Here, we aimed to investigate whether BIS had sufficient sensitivity to detect changes in body water content and to determine segmental water distribution after carbohydrate loading. Eight subjects consumed a high-carbohydrate diet containing 12 g carbohydrates·kg body mass(-1)·day(-1) for 72 h after glycogen depletion cycling exercise. Changes in muscle glycogen concentration were measured by (13)C-magnetic resonance spectroscopy, and total body water (TBW) was measured by the deuterium dilution technique (TBWD2O). ICW and ECW in the whole body (wrist-to-ankle) and in each body segment (arm, trunk, and leg) were assessed by BIS. Muscle glycogen concentration [72.7 ± 10.0 (SD) to 169.4 ± 55.9 mmol/kg wet wt, P < 0.001] and TBWD2O (39.3 ± 3.2 to 40.2 ± 3.0 kg, P < 0.05) increased significantly 72 h after exercise compared with baseline, respectively. Whole-body BIS showed significant increases in ICW (P < 0.05), but not in ECW. Segmental BIS showed significant increases in ICW in the legs (P < 0.05), but not in the arms or trunk. Our results suggest that increase in body water after carbohydrate loading can be detected by BIS and is caused by segment-specific increases in ICW.

Summary The doubly labeled water (DLW) method measures total energy expenditure (TEE) in free-living subjects. Several equations are used to convert isotopic data into TEE. Using the International Atomic Energy Agency (IAEA) DLW database (5,756 measurements of adults and children), we show considerable variability is introduced by different equations. The estimated rCO 2 is sensitive to the dilution space ratio (DSR) of the two isotopes. Based on performance in validation studies, we propose a new equation based on a new estimate of the mean DSR. The DSR is lower at low body masses (<10 kg). Using data for 1,021 babies and infants, we show that the DSR varies non-linearly with body mass between 0 and 10 kg. Using this relationship to predict DSR from weight provides an equation for rCO 2 over this size range that agrees well with indirect calorimetry (average difference 0.64%; SD = 12.2%). We propose adoption of these equations in future studies.

Background Appropriate energy intake (EI) is essential to prevent frailty. Because self-reported EI is inaccurate and has systematic errors, adequate biomarker calibration is required. This study examined the association between doubly labeled water (DLW)-calibrated EI and the prevalence of frailty among community-dwelling older adults. Method A cross-sectional study was performed using baseline data of 7,022 older adults aged ≥65 years in the Kyoto-Kameoka Study. EI was evaluated using a validated food frequency questionnaire (FFQ), and calibrated EI was obtained from a previously established equation using the DLW method. Physical and comprehensive frailty were defined by the Fried phenotype (FP) model and the Kihon Checklist (KCL), respectively. We used multivariable-adjusted restricted cubic spline logistic regression analysis. Results The prevalence of physical frailty was 14.8% and 13.6% in women and men, respectively. The spline models showed significant reverse J-shaped or U-shaped relationships between the prevalence of physical or comprehensive frailty against the DLW-calibrated EI, respectively. The lowest prevalence of both types of frailty was found at 1,900–2,000 kcal/d in women and 2,400–2,500 kcal/d in men, which corresponded to approximately 40 kcal/d/kg IBW (ideal body weight = 22 × height2) with DLW-calibrated EI. Uncalibrated EI underestimated approximately 20% compared with calibrated EI; underestimated EI were attenuated by calibration approach. Conclusions This study suggests that low EI has a greater detrimental effect compared with excessive EI, particularly on physical frailty. Using biomarkers to calibrate EI holds promise for providing accurate energy requirements to establish guidelines used in public health and clinical nutrition.

Accurate assessments of a target population’s energy intake (EI) are essential to prevent poor nutritional status. However, self-reported dietary records (DRs) or food frequency questionnaires (FFQs) are not always accurate, thereby requiring validation and calibration studies. This study aimed to validate the EI estimated by a FFQ using the doubly labeled water (DLW) method. Participants were 109 Japanese older adults (50 women and 59 men) aged 65–88 years. The EI was obtained by a DR and 47-item FFQ over 1 year. The total energy expenditure (TEE) was measured by DLW for ~2 weeks. EI was significantly lower than TEE (p < 0.01); ratios of EI assessed by DR and FFQ against TEE were 0.91 ± 0.17 and 0.82 ± 0.22, respectively. TEE was significantly and moderately correlated with the EI estimated by the DR (r = 0.45, p < 0.01) and FFQ (r = 0.37, p < 0.01). Furthermore, the EI correlation coefficients estimated by DR and the FFQ in this study were not significantly different (p = 0.46). The EI/TEE ratio was significantly and negatively correlated with the body mass index (BMI). In conclusion, EI estimated with a DR or FFQ modestly correlated with TEE, and calibrating EI with a developed equation in this study can attenuate the underestimation of EI.