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.

Objective: Psychosocial stress may influence the risk of disease through its association with oxidative DNA damage. We examined whether perceived stress and depressive symptoms were associated with urinary excretion of 8-hydroxydeoxyguanosine (8-OHdG), with mutual interaction on 8-OHdG. Methods: This cross-sectional study included 6517 individuals aged 45 to 74 years who participated, between 2010 and 2012, in a follow-up survey of an ongoing cohort study. Perceived stress during the past year was measured using a self-report questionnaire. Depressive symptoms were evaluated using the Zung Self-Rating Depression Scale. Urinary 8-OHdG concentrations were measured using a column switching high-pressure liquid chromatography system coupled to an electrochemical detector. Results: Higher perceived stress was significantly associated with higher 8-OHdG (2.1% increase per one-category increase of stress; p _trend = .025), even after adjusting for sex, age, supplement use, psychosocial factors, psychotropic medication use, smoking, and body mass index. This association was modestly attenuated after further adjustment for physical activity, suggesting possible mediation or confounding by this factor. Depressive symptoms were not significantly associated with 8-OHdG. No significant interaction was detected between perceived stress and depressive symptoms on 8-OHdG. Conclusions: In a general Japanese population, we found a weak positive association between perceived stress and urinary excretion of 8-OHdG, whereas no association was observed between depressive symptoms and 8-OHdG. Further studies are needed to examine whether the association between perceived stress and 8-OHdG is modified by depressive symptoms.

To determine energy density for rapid weight loss (RWL) of weight-classified sports, eight male elite wrestlers were instructed to lose 6% of body mass (BM) within 53 h. Energy deficit during the RWL was calculated by subtracting total energy expenditure (TEE) determined using the doubly labeled water method (DLW) from energy intake (EI) assessed with diet records. It was also estimated from body composition change estimated with the four-component model (4C) and other conventional methods. BM decreased significantly by 4.7 ± 0.5 kg (6.4 ± 0.5%). Total body water loss was the major component of the BM loss (71.0 ± 7.6%). TEE was 9446 ± 1422 kcal, and EI was 2366 ± 1184 kcal during the RWL of 53-h; therefore, the energy deficit was 7080 ± 1525 kcal. Thus, energy density was 1507 ± 279 kcal/kg ∆BM during the RWL, comparable with values obtained using the 4C, three-component model, dual energy X-ray absorptiometry, and stable isotope dilution. Energy density for RWL of wrestlers is lower than that commonly used (7400 or 7700 kcal/kg ΔBM). Although RWL is not recommended, we propose that commonly practiced extreme energy restriction such as 7400 or 7700 kcal/kg ΔBM during RWL appears to be meaningless.