A total of 301 women with overweight/obesity took part in the present cross-sectional study. There is a higher prevalence of poor sleep quality (19), depression, and anxiety disorders (19, 20) in women than in men. Moreover, women are more often affected by problems with their eating behaviors, such as craving for special foods (21), which results to a higher rate of obesity compared with men, which results in a higher rate of obesity compared with men (22). Thus, in the present study, we selected women as the study population. 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. 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. 41017-33893).
Body composition and anthropometric measurement
The body composition of all participants was mustered using a body composition analyzer (InBody770 scanner; InBody, Seoul, Korea) by following the manufacturer’s protocol. The 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. The height of participants was evaluated by a seca stadiometer, with exactness close to 0.1 cm. BMI was calculated as weight (kg)/hieght2 (m). Waist (WC) and hip circumference (HC) were measured in the smallest girth and the largest girth, respectively, with accuracy nearest to 0.1 cm.
Evaluation of food intake and DED
To assess the 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. FFQ assesses the usual food intake over the previous year. The high reliability and validity and of the FFQ have been confirmed previously (23). All FFQ questionnaires were completed by trained nutritionists. The energy of food consumed was evaluated using Nutritionist 4 software. 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) (24).
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), which evaluates depression, anxiety and, stress over the past week (25). The Pittsburgh Sleep Quality Index (PSQI) (26) was applied to subjectively measure the sleep quality of participants. It evaluates usual sleep habits during the past month. Total scores could range from 0 to 21, with a global sum of “5” or greater indicates poor sleep quality (26).
Measurement of biochemical parameters
Blood samples were obtained in the early morning between 8:00 and 10:00 am after a 10- to 12-hr overnight fasting. 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 a glucose oxidase method. Serum high-sensitive C-reactive protein (hs-CRP) was assessed with the use of the immunoturbidimetric assay.
DED was categorized into quartiles as followings: Q1 (0.61 to 1.00); Q2 (1.01 to 1.18); Q3 (1.19 to 1.44); and Q4 (1.45 to 3.79). Analyses of continuous variables to assess differences among quartile of DED were performed using the one-way analysis of variance (ANOVA). The results were adjusted for multiple comparisons using the tukey's post hoc test. Analysis of Covariance (ANCOVA) was then used 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).