Estimation of Energy Requirements for Adults: Tehran Lipid and Glucose Study

Objective: This study was conducted to determine the energy intake of adult residents of district 13 of Tehran and compare the results with their energy requirements. Design: In this cross-sectional study, 403 subjects were selected by random sampling, including 145 men and 151 women aged 25–50 years and 57 men and 50 women over 50 years old in the framework of Tehran Lipid and Glucose Study (TLGS). Measurements: Height, body weight, waist and hip circumferences were measured, and the body mass index (BMI) and waist-to-hip ratio (WHR) were calculated. Mean energy requirements for each sex-age group were estimated by multiplying specific coefficients (allocated to each group) by body weight and resting energy expenditure (REE), and the results of both methods were compared with mean energy values recommended by Food and Agriculture Organization (FAO) /World Health Organization (WHO) and the U.S. recommended dietary allowance (RDA). Dietary assessment was performed by 48-hour diet recall. A ratio of energy intake to basal metabolic rate lower than 1.27 was considered as under-reporting. Physical activity was evaluated by standard questionnaire of the Lipid Research Clinics (LRC). Results: Women were significantly more overweight and obese than men (p < 0.001) and older women were more obese than younger ones (p < 0.05). Only one-third of the study population had adequate physical activity. Women had significantly lower physical activity than men (p < 0.01). Energy requirements for both age and sex groups were lower than recommended daily allowances for energy: men 25–50; 2576 vs. 2900; men > 50: 2155 vs. 2300; women 20–50: 2045 vs. 2200 and women > 50: 1817 vs. 1900 kilocalories (kcal). Reported energy intake of men was higher and that of women was lower than the RDA. Forty percent of women and 14% of men under-reported their energy intake. Conclusion: The energy requirement of the average Tehranian is lower than daily allowances; conditions of obesity and overweight are more prevalent in women. There is high frequency of under-reporting of energy intake in women. Lifestyle modifications to improve dietary habits and to increase physical activity are recommended to decrease overweight and obesity in urban population of Tehran.