Does Ramadan Fasting Alter the Resting Metabolic Rate, Body Composition and Dietary Intake of Overweight and Obese Adults?

Document Type : Research Paper


1 Department of Nutrition, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

2 Metabolic Syndrome Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.

3 Department of Public Health, North Khorasan University of Medical Sciences, Bojnurd, Iran.

4 Department of community medicine, Medical School, Mashhad University of Medical Sciences, Mashhad, Iran


Introduction: Ramadan fasting (RF) is a model of calorie restriction similar to intermittent fasting, which is extensively practiced by a large population of Muslims. Limited and controversial studies have investigated the physiological changes induced by 30 days of RF. The present study aimed to evaluate the effects of Ramadan fasting on the resting metabolic rate and body composition of overweight and obese individuals. Methods: This study was conducted on 21 men and women aged 18-40 years. The subjects avoided eating and drinking for one month during the holy month of Ramadan (at least 20 days) and received a routine diet without an intervention between Iftar and dawn (Sahur). Before and after the study, the energy of the basal metabolic rate was measured via indirect calorimetry, and body composition was measured by bioimpedance (InBody s10). In addition, the physical activity of each participant was evaluated using a pedometer during one week. During the study, each participant received a 24-hour recall once a week. Results: Compared to the pre-study period and after four weeks of RF, body weight (77.91±11.83 vs. 77.01 ±11.75 kg; P<0.05) decreased, while the body fat percentage (34.84±7.07 vs. 38.48±5.93%; P<0.001) increased. However, the resting metabolic rate had no significant changes (P=0.641), while the total fat-free mass and visceral fat mass significantly deceased after the study (P<0.001). The mean daily energy intake increased after the study compared to before RF (3,290±785.82 vs. 2,458±535.32 kcal; P<0.05). Moreover, the total carbohydrate and sugar intake increased significantly after RF (437.04±101.02 and 194.04±56.87 g per day vs. 310.09±87.12 and 60.42±31.57 g per day). Conclusion: According to the results, RF may effectively improve metabolic parameters and prevent the decline of the basal metabolic rate if accompanied by nutritional support and healthy dietary recommendations.


  1. Djalalinia S, Saeedi Moghaddam S, Sheidaei A, Rezaei N, Naghibi Iravani SS, Modirian M, et al. Patterns of obesity and overweight in the iranian population: findings of steps 2016. Front Endocrinol. 2020;11:42.
  2. Bastard J-P, Maachi M, Lagathu C, Kim MJ, Caron M, Vidal H, et al. Recent advances in the relationship between obesity, inflammation, and insulin resistance. Eur Cytokine Netw . 2006;17(1):4-12.
  3. Tremblay A, Therrien F. Physical activity and body functionality: implications for obesity prevention and treatment. Can J Physiol Pharmacol. 2006;84(2):149-56.
  4. Alinezhad-Namaghi M, Eslami S, Nematy M, Khoshnasab A, Rezvani R, Philippou E, et al. Intermittent fasting during Ramadan and its effects in individuals with metabolic syndrome. Nutr Today. 2019;54(4):159-64.
  5. Ali Babaei A, Ghasemi M, Tavakoli Ghouchani H, Yousefi A. Evaluation of the effects of Islamic fasting on the biochemical markers of health. J Nutr Fast Health. 2016;4(2):88-91.
  6. Kul S, Savaş E, Öztürk ZA, Karadağ G. Does Ramadan fasting alter body weight and blood lipids and fasting blood glucose in a healthy population? A meta-analysis. J Relig Health. 2014;53(3):929-42.
  7. Maughan RJ, Fallah J, Coyle EF. The effects of fasting on metabolism and performance. Br J Sports Med. 2010;44(7):490-4.
  8. Khattak MMAK, Bakar IA, Yeim L. Does religious fasting increase fat free mass (FFM) and reduce abdominal obesity?. Nutr Food Sci. 2012.
  9. Mansi KMS. Study the effects of Ramadan fasting on the serum glucose and lipid profile among healthy Jordanian students. Am J Appl Sci. 2007;4(8):565-9.
  10. Sadeghirad B, Motaghipisheh S, Kolahdooz F, Zahedi MJ, Haghdoost AA. Islamic fasting and weight loss: a systematic review and meta-analysis. Public Health Nutr. 2014;17(2):396-406.
  11. Mazidi M, Karimi E, Rezaee P, Nematy M, Salehi M. The effects of Ramadan fasting on body composition. Shiraz E Med J. 2014;15(1).
  12. Lessan N, Saadane I, Alkaf B, Hambly C, Buckley AJ, Finer N, et al. The effects of Ramadan fasting on activity and energy expenditure. Am J Clin Nutr. 2018;107(1):54-61.
  13. Haghdoost AA, Poorranjbar M. The interaction between physical activity and fasting on the serum lipid profile during Ramadan. Singapore Med J. 2009;50(9):897-901.
  14. Zauner C, Schneeweiss B, Kranz A, Madl C, Ratheiser K, Kramer L, et al. Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine. Am J Clin Nutr. 2000;71(6):1511-5.
  15. El Ati J, Beji C, Danguir J. Increased fat oxidation during Ramadan fasting in healthy women: an adaptative mechanism for body-weight maintenance. Am J Clin Nutr. 1995;62(2):302-7.
  16. McNeil J, Mamlouk MM, Duval K, Schwartz A, Nardo Junior N, Doucet É. Alterations in metabolic profile occur in normal-weight and obese men during the Ramadan fast despite no changes in anthropometry. J Obes. 2014; 2014.
  17. Harder-Lauridsen NM, Rosenberg A, Benatti FB, Damm JA, Thomsen C, Mortensen EL, et al. Ramadan model of intermittent fasting for 28 d had no major effect on body composition, glucose metabolism, or cognitive functions in healthy lean men. Nutrition. 2017;37:92-103.
  18. Mansoori A, Khosravi M, Asadi M. Effects of Evening Meal Timing on Weight Loss: A Pilot Open-Labelled Randomized Clinical Trial. J Adv Med Biomed Res. 2020; 28 (126): 41-6.
  19. Ziaee V, Razaei M, Ahmadinejad Z, Shaikh H, Yousefi R, Yarmohammadi L, et al. The changes of metabolic profile and weight during Ramadan fasting. Singapore Med J. 2006;47(5):409-14.
  20. Al-Hourani H, Atoum M. Body composition, nutrient intake and physical activity patterns in young women during Ramadan. Singapore Med J. 2007;48(10):906.
  21. Fernando HA, Zibellini J, Harris RA, Seimon RV, Sainsbury A. Effect of Ramadan fasting on weight and body composition in healthy non-athlete adults: a systematic review and meta-analysis. Nutrients. 2019;11(2):478.
  22. Nachvak SM, Pasdar Y, Pirsaheb S, Darbandi M, Niazi P, Mostafai R, et al. Effects of Ramadan on food intake, glucose homeostasis, lipid profiles and body composition composition. Eur J Clin Nutr. 2019;73(4):594-600.
  23. A Babaei AA, Khosravi M, Ghasemi M, Tavakoli Ghouchani H. Evaluation of the Effects of Islamic Fasting on the Biochemical Markers of Health. J Fast Health. 4 (2), 88-91.