Effect of Intermittent Fasting on Appetite and Dietary Intake

Document Type : Original Article

Authors

1 Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

2 Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran

3 Department of Biostatistics, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran

4 Social Determinants of Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

5 Brighton and Sussex Medical School, Division of Medical Education, Falmer, Brighton, Sussex BN1 9PH, UK

6 Transplant Research Center, Clinical Research Institute, Mashhad University of Medical Sciences, Mashhad, Iran

10.30476/ijns.2026.105697.1402

Abstract

Background: The role of 5:2 intermittent fasting (IF) in influencing appetite to improve dietary compliance and sustain long-term weight loss is unclear. This study aimed to evaluate changes in appetite on fasting days for an IF group and to compare dietary intakes between the IF and continuous calorie restriction (CR) groups.
Methods: A three-month longitudinal study was conducted using data from the Iranian National Obesity Registry. Eligible participants (body mass index (BMI) ≥25 kg/m², 18-65 years old) were assigned to a 5:2 IF group (n=40) or a CR group (n=42) for 12 weeks. To evaluate appetiterelated variables on fasting days, we used a validated visual analog scale to measure hunger, fullness, estimated eating capacity, and other factors related to appetite. These measurements were taken at the beginning and the end of fasting days. To assess dietary intake, we conducted 3-day food recalls at baseline and after three months.
Results: Both groups showed significant reductions in macro- and micronutrient intakes compared to baseline values, but no significant differences between the two groups were observed (p>0.05). Hunger and estimated eating capacity significantly decreased on fasting days (p=0.02 and p<0.001, respectively), and fullness significantly increased (p=0.03).
No significant changes were observed in satisfaction (p=0.88) or eating desire intensity (p=0.41).
Conclusion: These findings suggested that the 5:2 IF regimen effectively reduced hunger and estimated eating capacity; while increasing fullness on fasting days. These effects may contribute to the efficacy of IF as a weight loss strategy over a 12-week period.

Highlights

Niloufar Abdollahpour (Google Scholar)

Maryam Alinezhad-Namaghi (Google Scholar)

Majid Ghayour-Mobarhan (Google Scholar)

Keywords

References

  1. 1. Volpe M, Gallo G. Obesity and cardiovascular disease: An executive document on pathophysiological and clinical links promoted by the Italian Society of Cardiovascular Prevention (SIPREC). Front Cardiovasc Med. 2023;10:1136340. DOI: 10.3389/fcvm.2023.1136340. PMID: 36993998.
  2. Zare P, Sohrabi Z, Haghighat N, et al. Changes in Ferritin and Hemoglobin Levels in Obese Patients before and after Bariatric Surgery: A Cohort Study. Int J Nutr Sci. 2024;9:101-108. DOI: 10.30476/IJNS.2024.101242.1294.
  1. Carter S, Clifton PM, Keogh JB. Effect of intermittent compared with continuous energy restricted diet on glycemic control in patients with type 2 diabetes: a randomized noninferiority trial. JAMA Netw Open. 2018;1:e180756-e. DOI: 10.1001/jamanetworkopen.2018.0756. PMID: 30646030.
  2. Khandouzi M, Haghighat N, Zare M, et al. Anthropometric, Body Composition, and Biochemical Measurements in Morbidly Obese Patients Prior to Bariatric Surgery.
  1. Varady KA, Cienfuegos S, Ezpeleta M, et at. Cardiometabolic benefits of intermittent fasting. Annu Rev Nutr. 2021;41:333-61. DOI: 10.1146/annurev-nutr-052020-041327. PMID: 34633860.
  2. Hajek P, Przulj D, Pesola F, et al. A randomised controlled trial of the 5: 2 diet. PLoS One. 2021;16:e0258853. DOI: 10.1371/journal.pone.0258853. PMID: 34788298.
  3. Hetherington M, Cunningham K, Dye L, et al. Potential benefits of satiety to the consumer: scientific considerations. Nutr Res Rev. 2013;26:22-38. DOI: 10.1017/S0954422413000012. PMID: 23680169.
  4. Stubbs J, Brogelli D, Pallister C, et al. Behavioural and motivational factors associated with weight loss and maintenance in a commercial weight management programme. Open Obes J. 2012;4:35-43. DOI: 10.2174/1876823701204010035.
  5. Nymo S, Coutinho S, Eknes P, et al. Investigation of the long-term sustainability of changes in appetite after weight loss. Int J Obes. 2018;42:1489-99. DOI: 10.1038/s41366-018-0119-9. PMID: 29930313.
  6. Martins C, Dutton GR, Hunter GR, et al. Revisiting the Compensatory Theory as an explanatory model for relapse in obesity management. Am J Clin Nutr. 2020;112:1170-9. DOI: 10.1093/ajcn/nqaa243. PMID: 32936896.
  7. Batra P, Das SK, Salinardi T, et al. Eating behaviors as predictors of weight loss in a 6 month weight loss intervention. Obesity. 2013;21:2256-63. DOI: 10.1002/oby.20404. PMID: 23512619.
  8. Ghahremani A, Barati M, Namdar Ahmadabad H. Unlocking the Potential of Intermittent

Fasting as a Dietary Intervention for Chronic Inflammatory Diseases. Int J Nutr Sci. 2025;10:382-394. DOI: 10.30476/ijns.2025.105356.1393.

  1. Arciero PJ, Poe M, Mohr AE, et al. Intermittent fasting and protein pacing are superior to caloric restriction for weight and visceral fat loss. Obesity. 2023;31:139-49.
  2. Beaulieu K, Casanova N, Oustric P, et al. Matched weight loss through intermittent or continuous energy restriction does not lead to compensatory increases in appetite and eating behavior in a randomized controlled trial in women with overweight and obesity. J Nutr. 2020;150:623-33. DOI: 10.1093/jn/nxz296. PMID: 31825067.
  3. Bhutani S, Klempel MC, Kroeger CM, et al. Effect of exercising while fasting on eating behaviors and food intake. J Int Soc Sports Nutr. 2013;10:50. DOI: 10.1186/1550-2783-10-50. PMID: 24176020.
  4. Hoddy KK, Gibbons C, Kroeger CM, et al. Changes in hunger and fullness in relation to gut peptides before and after 8 weeks of alternate day fasting. Clin Nutr. 2016;35:1380-5. DOI: 10.1016/j.clnu.2016.03.011. PMID: 27062219.
  5. Coutinho SR, Halset EH, Gåsbakk S, et al. Compensatory mechanisms activated with intermittent energy restriction: a randomized control trial. Clin Nutr. 2018;37:815-23. DOI: 10.1016/j.clnu.2017.04.002. PMID: 28446382.
  6. Drummond MD, Soares PS, Savoi LA, et al. Fasting reduces satiety and increases hunger but does not affect the performance in resistance training. Biol Sport. 2023;41:57-65. DOI: 10.5114/biolsport.2024.131814. PMID: 38524818.
  7. Elsworth RL, Monge A, Perry R, et al. The effect of intermittent fasting on appetite: a systematic review and meta-analysis. Nutrients. 2023;15:2604. DOI: 10.3390/nu15112604. PMID: 37299567.
  8. Sepple C, Read N. Gastrointestinal correlates of the development of hunger in man. Appetite. 1989;13:183-91. DOI: 10.1016/0195-6663(89)90011-1. PMID: 2596841.
  9. Mehrabani D, Masoumi SJ, Masoumi AS, et al. Role of Diet in Mesenchymal Stem Cells’ Function: A Review. Int J Nutr Sci. 2023;8:9-19. DOI: 10.30476/IJNS.2023.97788.1221.
  10. Homayoun M, Mehrabani D, Edalatmanesh MA, et al. The Role of Lithium Chloride in Nutrition and Stem Cell Growth Kinetics: A Review. Int J Nutr Sci. 2021;6:6-13. DOI: 10.30476/IJNS.2021.88801.1104.
  11. Hedayati A, Homayuon M, Mobaracky A, et al. Lithium Chloride, Ketogenic Diet and Stem Cell Transplantation in Treatment of Bipolar Disorder.
  1. Ahmadi A, Hajiani N, Keshavarzi S. Anthropometric Index and Diet Pattern of Fasting Men in Khvormuj. Int J Nutr Sci. 2017;2:27-32.
  2. Kroeger CM, Trepanowski JF, Klempel MC, et al. Eating behavior traits of successful weight losers during 12 months of alternate-day fasting: An exploratory analysis of a randomized controlled trial. Nutr Health. 2018;24:5-10. DOI: 10.1177/0260106017753487. PMID: 29353535.
  3. Strohacker K, McCaffery J, MacLean P, et al. Adaptations of leptin, ghrelin or insulin during weight loss as predictors of weight regain: a review of current literature. Int J Obes. 2014;38:388-96. DOI: 10.1038/ijo.2013.118. PMID: 23801147.
  4. Woods SC, Lutz TA, Geary N, et al. Pancreatic signals controlling food intake; insulin, glucagon and amylin. Philos Trans R Soc Lond B Biol Sci. 2006;361:1219-35. DOI: 10.1098/rstb.2006.1858. PMID: 16815800.
  5. Rubinsztein DC. Autophagy—alias self‐eating—appetite and ageing. EMBO Rep. 2012;13:173-4. DOI: 10.1038/embor.2012.5. PMID: 22302030.
  6. Fernández ÁF, Bárcena C, Martínez-García GG, et al. Autophagy couteracts weight gain, lipotoxicity and pancreatic β-cell death upon hypercaloric pro-diabetic regimens. Cell Death Dis. 2017;8:e2970. DOI: 10.1038/cddis.2017.373. PMID: 28771229.
  7. Irani D, Mehrabani D, Karimi-Busheri F. Mesenchymal Stem Cells in Regenerative Medicine, Possible Applications in The Restoration of Spermatogenesis: A Review. Cell J. 2024;26:169-184. DOI: 10.22074/cellj.2024.2015141.1442. PMID: 38628090.
  8. Frank J, Gupta A, Osadchiy V, et al. Brain–gut–microbiome interactions and intermittent fasting in obesity. Nutrients. 2021;13:584.
  9. van der Klaauw AA, Keogh JM, Henning E, et al. High protein intake stimulates postprandial GLP1 and PYY release. Obesity. 2013;21:1602-7. DOI: 10.1002/oby.20154. PMID: 23666746.
  10. Masoumi SJ, Khademolhosseini F, Mehrabani D, et al. Correlation of quality of life with gastroesophageal reflux disease amongst Qashqai nomads in Iran. Arch Iran Med. 2012;15:747-50. PMID: 23199245.
  11. Paoli A, Tinsley G, Bianco A, et al. The influence of meal frequency and timing on health in humans: the role of fasting. Nutrients. 2019;11:719. DOI: 10.3390/nu11040719. PMID: 30925707.
  12. Gliklich RE, Leavy MB, Dreyer NA. Analysis, interpretation, and reporting of registry data to evaluate outcomes. Registries for Evaluating Patient Outcomes: A User’s Guide [Internet] 4th edition: Agency for Healthcare Research and Quality (US); 2020.

Files

Share

How to cite

Statistics