A total of 301 overweight/obese women took part in the present cross-sectional study. All subjects were randomly recruited from individuals referring to health centers in Tehran during 2016-2017. Inclusion criteria were age 18–56 years, being overweight or obese (body mass index (BMI) ≥25), absence of any acute or chronic infection, no alcohol or drug abuse, no history of hypertension, and not being pregnant. Based on exclusion criteria, prospective subjects with a history of cardiovascular disease, cancer, sustained hypertension, diabetes, thyroid disease, cancer, acute or chronic infections, liver and kidney disease, and smokers were excluded from the study. Enrolment was voluntary, and the participants were informed about the objectives and all the stages of this study. Written informed consent was obtained from all participants before taking part in the study. The study protocol was approved by the local ethical committee of Tehran University of Medical Sciences (IR. TUMS.VCR.REC. 95-04-161-33893).
Body composition and anthropometric measurement
Body composition of all participants was mustered using a body composition analyzer (InBody770 scanner; InBody, Seoul, Korea) by following the manufacturer’s protocol. Weight of the individuals was measured with the use of a digital scale (Seca, Hamburg, Germany) in light clothing and without shoes with precision near to 0.1 kg. Height of participants was evaluated by a seca stadiometer, with exactness close to 0.1 cm in a standing position. BMI was calculated as weight (kg)/hieght2 (m). Furthermore, Waist (WC) and hip circumference (HC) were measured in the smallest girth and in the largest girth, respectively, with the use of an inelastic tape with accuracy nearest to 0.1 cm.
Evaluation of food intake and DED
To assess dietary intake of participants, a semi-quantitative food frequency questionnaire (sq-FFQ) with 147 Iranian food items, containing a list of foods with standard serving sizes was used. The high reliability and validity and of the FFQ have been confirmed previously (19). All FFQ questionnaires were completed by trained nutritionists. The energy of food consumed was evaluated using Nutritionist 4 software (First Databank Inc., Hearst Corp., San Bruno, CA). DED was calculated by dividing the total dietary energy intake from consumed food (kcal/d) by the total weight (g/d) of consumed foods (excluding beverages) (20).
Assessment of mental health and sleep quality
Mental health was evaluated with the use of the 21-question version of the Depression Anxiety Stress Scales (DASS-21). The DASS-21 is a self-administered psychological questionnaire containing of 3 scales. Each subscale has 7 items based on 4-point Likert scale (0–3 scale) (Never, Sometimes, Often, Almost, Always)(21). The Pittsburgh Sleep Quality Index (PSQI) (22) was applied to subjectively measure the sleep quality of participants. Total scores could range from 0 to 21, with global sum of “5”or greater indicates poor sleep quality (22).
Measurement of biochemical parameters
Blood samples were obtained from the forearm of all participants in the early morning between 8:00 and 10:00 am after a 10- to 12-hr overnight fasting. The samples were centrifuged at 3,500 rpm for 10 min at −70oC and the separated sera stored at a temperature of −80 °C. Serum concentrations of high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) were evaluated by using of enzymatic approaches using related kits (Pars Azemun, Iran) and autoanalyzer system. Insulin level was assessed using an ELISA kit (Human insulin ELISA kit,DRG Pharmaceuticals, GmbH, Germany), and fasting concentration of glucose was measured using glucose oxidase method. Serum high-sensitive C-reactive protein (hs-CRP) was assessed with the use of immunoturbidimetric assay.
Analyses of continuous variables to assess differences among quartile of DED were performed using one-way analysis of variance (ANOVA). Analysis of Covariance (ANCOVA) was then used in order to find the difference between the means of investigated variables across quartiles of DED adjusted for age, physical activity and BMI. The logistic regression analysis was applied to find the relation of DED to sleep quality, stress, anxiety, and depression; this model was then adjusted for age, physical activity and BMI. The level of significance was set at a probability of ≤ 0.05 for all tests. All statistical analyses were conducted using a statistical Package for Social Science (Version 22.0; SPSS Inc., Chicago IL, USA).