Intermittent fasting (IF) is an eating pattern that alternates periods of eating and fasting and has attracted significant attention in recent years to help people live longer and improve their overall health. The main types of IF include:

  • Time-restricted eating (TRE)2
  • Alternate-day fasting (ADF)3
  • Modified alternate-day fasting (MADF)4
  • Time-restricted fasting (TRF) – early or late (16:8 protocol)5
  • Fast-mimicking diet (FMD)6
  • 5:2 meal replacement plan (5:2 MR)7

  1. Persynaki A, Karras S, Pichard C, (2017). Unraveling the metabolic health benefits of fasting related to religious beliefs: a narrative review. Nutrition. 35:14-20.
  2. Manoogian ENC, Laferrère B (2023). Time-restricted eating: What we know and where the field is going. Obesity (Silver Spring). 31 Suppl 1(Suppl 1):7-8.
  3. Longo VD, Di Tano M, Mattson MP, et al (2021). Intermittent and periodic fasting, longevity and disease. Nat Aging. 1(1):47-59.
  4. Hooshiar SH, Yazdani A, Jafarnejad S, (2023). Alternate-day modified fasting diet improves weight loss, subjective sleep quality and daytime dysfunction in women with obesity or overweight: a randomized, controlled trial. Front. Nutr. 10:1174293.
  5. Anton SD, Moehl K, Donahoo WT et al (2018). Flipping the metabolic switch: understanding and applying the health benefits of fasting. Obesity (Silver Spring). 26(2):254-268.
  6. Popa AD, Gherasim A, Mihalache L, et al. (2025). Mimicking Diet for Metabolic Syndrome: A Narrative Review of Human Studies. Metabolites. 23;15(3):150.
  7. Brandhorst S, Choi IY, Wei M, et al (2015). A periodic diet that mimics fasting promotes multi-system regeneration, enhanced cognitive performance, and healthspan. Cell Metab. 22(1):86-99.
  8. Reddy LB, Reddy VS, Saier MH (2024). Health Benefits of Intermittent Fasting. Microb Physiol 20. 34 (1): 142–152.
  9. Hazzard LB. (1908). Fasting for the cure of disease. (1st ed.), Seattle, Washington, Harrison Publishing Co.
  10. Song DK, Kim YW (2023). Beneficial effects of intermittent fasting: a narrative review. J Yeungnam Med Sci.40(1):4-11.
  11. Sun M, Yao W, Wang X et al (2024). Intermittent fasting and health outcomes: an umbrella review of systematic reviews and meta-analyses of randomised controlled trials. eClinicalMedicine, 70.
  12. Singh I, Bhat S, Tamatta R, et al (2026). Interplay Between Autophagy, Cellular Senescence, and Brain Aging: Neuroprotective Implications of Intermittent Fasting. Cell Mol Neurobiol. 11;46(1):75.
  13. Mulas A, Cienfuegos S, Ezpeleta M, et al (2023). Effect of intermittent fasting on circulating inflammatory markers in obesity: A review of human trials. Front Nutr. 10:1146924.
  14. McGuire BD, Schlussel Y, Shah A, et al. (2026). Time-Restricted Eating and Caloric Restriction Influences Cognition in Older Women: A Randomized Controlled Trial. Aging and Chronic Disease (II), (Poster Session). American Society for Nutrition. Jul 2026, Washington D.C.
  15. Bahadoran Z, Mirmiran P, Kashfi K, et al (2024). Effects of time-restricted feeding (TRF)-model of intermittent fasting on adipose organ: a narrative review. Eat Weight Disord. 24;29(1):77.
  16. Gabel K et al. (2018). Effects of 8-hour time restricted feeding on body weight and metabolic disease risk factors in obese adults: a pilot study. Nutr. Healthy Aging 4, 345–353.
  17. Petridi F, Geurts JMW, Nyakayiru J, et al. (2024). Effects of Early and Late Time-Restricted Feeding on Parameters of Metabolic Health: An Explorative Literature Assessment. Nutrients. 16(11):1721.
  18. Manoogian ENC, Chow LS, Taub PR, et al. (2022). Time-restricted Eating for the Prevention and Management of Metabolic Diseases. Endocr Rev. 43(2):405-436.
  19. Yi X, Abas R, Raja MR, et al. (2025). Time-restricted feeding reduced blood pressure and improved cardiac structure and function by regulating both circulating and local renin-angiotensin systems in spontaneously hypertensive rat model. PLoS One. 20(4):e0321078.
  20. Longo V. (2025). Fasting Mimicking Diet Cycles, Regeneration, Biological Age, and Disease. Innov Aging. 9(Suppl 2):igaf122.1389.
  21. Liu Y, Zhou L, Xue J. (2025). The Role of Fasting-Mimicking Diet in Cancer Therapy: Mechanisms, Challenges, and Clinical Prospects]. Sichuan Da Xue Xue Bao Yi Xue Ban. 56(3):873-880.
  22. Salvadori G, Zanardi F, Iannelli F, et al. (2021). Fasting-mimicking diet blocks triple-negative breast cancer and cancer stem cell escape. Cell Metab. 33(11):2247-2259.e6.
  23. Guo L, Xi Y, Jin W, (2024). A 5:2 Intermittent Fasting Meal Replacement Diet and Glycemic Control for Adults With Diabetes: The EARLY Randomized Clinical Trial. JAMA Netw Open. 7(6):e2416786.
  24. Wu C, Chen B, Yu J, (2025). Effect of the 5:2 Diet on Weight Loss and Cardiovascular Disease Risk Factors in Overweight and/or Obesity: A Systematic Review and Meta-Analysis. Int J Endocrinol. 2025:6658512
  25. Sainsbury A, Wood RE, Seimon RV, et al. (2018). Rationale for Novel Intermittent Dieting Strategies to Attenuate Adaptive Responses to Energy Restriction. Obes. Rev.19:47–60.
  26. Pierre K, Pellerin L, (2005). Monocarboxylate transporters in the central nervous system: distribution, regulation and function. J Neurochem. 94(1):1–14
  27. Jensen NJ, Wodschow HZ, Nilsson M, et al (2020). Effects of Ketone Bodies on Brain Metabolism and Function in Neurodegenerative Diseases. Int J Mol Sci. 21(22):8767.
  28. Singh I, Bhat S, Tamatta R, et al (2026). Interplay Between Autophagy, Cellular Senescence, and Brain Aging: Neuroprotective Implications of Intermittent Fasting. Cell Mol Neurobiol. 46(1):75.
  29. Jenkins D. (2025). Metabolic Effects of Intermittent Fasting: Insights from Clinical Trials. J Clin Nutr Metab 2025, 9:1.
  30. Shalabi H, Hassan AS 4th, Al-Zahrani FA, et al. (2023). Intermittent Fasting: Benefits, Side Effects, Quality of Life, and Knowledge of the Saudi Population. Cureus. 15(2):e34722.
  31. Jackson JM, Blaine D, Powell-Tuck J, et al. (2006). Macro- and micronutrient losses and nutritional status resulting from 44 days of total fasting in a non-obese man. Nutrition. 22(9):889-97.
  32. Conn MO, Marko DM, Schertzer JD. (2024). Type 2 Diabetes Alters Metabolic Fuel Selection During Intermittent Fasting. J Endocr Soc. 8(Suppl 1):bvae163.984.
  33. Paulussen KJM, McKenna CF, Beals JW, et al. (2021). Anabolic Resistance of Muscle Protein Turnover Comes in Various Shapes and Sizes. Front Nutr. 8:615849.
  34. Williamson E, Moore DR. (2021). A Muscle-Centric Perspective on Intermittent Fasting: A Suboptimal Dietary Strategy for Supporting Muscle Protein Remodeling and Muscle Mass? Front Nutr. 8:640621
  35. Blumberg J, Hahn SL, Bakke J. (2023). Intermittent fasting: consider the risks of disordered eating for your patient. Clin Diabetes Endocrinol. 9(1):4.
  36. Sebastian SA, Shah Y, Arsene C. (2024). Intermittent fasting and cardiovascular disease: A scoping review of the evidence. Dis Mon. 70(11):101778

About the Author: Giuliana Rocca, ANutr

Giuliana is a Programme Manager in University College Dublin. She delivers nutrition workshops and mentors in cooking programmes, providing advice on sustainable diets and healthy food choices to individuals, families and communities.

Leave A Comment

Intermittent fasting (IF) is an eating pattern that alternates periods of eating and fasting and has attracted significant attention in recent years to help people live longer and improve their overall health. The main types of IF include:

  • Time-restricted eating (TRE)2
  • Alternate-day fasting (ADF)3
  • Modified alternate-day fasting (MADF)4
  • Time-restricted fasting (TRF) – early or late (16:8 protocol)5
  • Fast-mimicking diet (FMD)6
  • 5:2 meal replacement plan (5:2 MR)7

  1. Persynaki A, Karras S, Pichard C, (2017). Unraveling the metabolic health benefits of fasting related to religious beliefs: a narrative review. Nutrition. 35:14-20.
  2. Manoogian ENC, Laferrère B (2023). Time-restricted eating: What we know and where the field is going. Obesity (Silver Spring). 31 Suppl 1(Suppl 1):7-8.
  3. Longo VD, Di Tano M, Mattson MP, et al (2021). Intermittent and periodic fasting, longevity and disease. Nat Aging. 1(1):47-59.
  4. Hooshiar SH, Yazdani A, Jafarnejad S, (2023). Alternate-day modified fasting diet improves weight loss, subjective sleep quality and daytime dysfunction in women with obesity or overweight: a randomized, controlled trial. Front. Nutr. 10:1174293.
  5. Anton SD, Moehl K, Donahoo WT et al (2018). Flipping the metabolic switch: understanding and applying the health benefits of fasting. Obesity (Silver Spring). 26(2):254-268.
  6. Popa AD, Gherasim A, Mihalache L, et al. (2025). Mimicking Diet for Metabolic Syndrome: A Narrative Review of Human Studies. Metabolites. 23;15(3):150.
  7. Brandhorst S, Choi IY, Wei M, et al (2015). A periodic diet that mimics fasting promotes multi-system regeneration, enhanced cognitive performance, and healthspan. Cell Metab. 22(1):86-99.
  8. Reddy LB, Reddy VS, Saier MH (2024). Health Benefits of Intermittent Fasting. Microb Physiol 20. 34 (1): 142–152.
  9. Hazzard LB. (1908). Fasting for the cure of disease. (1st ed.), Seattle, Washington, Harrison Publishing Co.
  10. Song DK, Kim YW (2023). Beneficial effects of intermittent fasting: a narrative review. J Yeungnam Med Sci.40(1):4-11.
  11. Sun M, Yao W, Wang X et al (2024). Intermittent fasting and health outcomes: an umbrella review of systematic reviews and meta-analyses of randomised controlled trials. eClinicalMedicine, 70.
  12. Singh I, Bhat S, Tamatta R, et al (2026). Interplay Between Autophagy, Cellular Senescence, and Brain Aging: Neuroprotective Implications of Intermittent Fasting. Cell Mol Neurobiol. 11;46(1):75.
  13. Mulas A, Cienfuegos S, Ezpeleta M, et al (2023). Effect of intermittent fasting on circulating inflammatory markers in obesity: A review of human trials. Front Nutr. 10:1146924.
  14. McGuire BD, Schlussel Y, Shah A, et al. (2026). Time-Restricted Eating and Caloric Restriction Influences Cognition in Older Women: A Randomized Controlled Trial. Aging and Chronic Disease (II), (Poster Session). American Society for Nutrition. Jul 2026, Washington D.C.
  15. Bahadoran Z, Mirmiran P, Kashfi K, et al (2024). Effects of time-restricted feeding (TRF)-model of intermittent fasting on adipose organ: a narrative review. Eat Weight Disord. 24;29(1):77.
  16. Gabel K et al. (2018). Effects of 8-hour time restricted feeding on body weight and metabolic disease risk factors in obese adults: a pilot study. Nutr. Healthy Aging 4, 345–353.
  17. Petridi F, Geurts JMW, Nyakayiru J, et al. (2024). Effects of Early and Late Time-Restricted Feeding on Parameters of Metabolic Health: An Explorative Literature Assessment. Nutrients. 16(11):1721.
  18. Manoogian ENC, Chow LS, Taub PR, et al. (2022). Time-restricted Eating for the Prevention and Management of Metabolic Diseases. Endocr Rev. 43(2):405-436.
  19. Yi X, Abas R, Raja MR, et al. (2025). Time-restricted feeding reduced blood pressure and improved cardiac structure and function by regulating both circulating and local renin-angiotensin systems in spontaneously hypertensive rat model. PLoS One. 20(4):e0321078.
  20. Longo V. (2025). Fasting Mimicking Diet Cycles, Regeneration, Biological Age, and Disease. Innov Aging. 9(Suppl 2):igaf122.1389.
  21. Liu Y, Zhou L, Xue J. (2025). The Role of Fasting-Mimicking Diet in Cancer Therapy: Mechanisms, Challenges, and Clinical Prospects]. Sichuan Da Xue Xue Bao Yi Xue Ban. 56(3):873-880.
  22. Salvadori G, Zanardi F, Iannelli F, et al. (2021). Fasting-mimicking diet blocks triple-negative breast cancer and cancer stem cell escape. Cell Metab. 33(11):2247-2259.e6.
  23. Guo L, Xi Y, Jin W, (2024). A 5:2 Intermittent Fasting Meal Replacement Diet and Glycemic Control for Adults With Diabetes: The EARLY Randomized Clinical Trial. JAMA Netw Open. 7(6):e2416786.
  24. Wu C, Chen B, Yu J, (2025). Effect of the 5:2 Diet on Weight Loss and Cardiovascular Disease Risk Factors in Overweight and/or Obesity: A Systematic Review and Meta-Analysis. Int J Endocrinol. 2025:6658512
  25. Sainsbury A, Wood RE, Seimon RV, et al. (2018). Rationale for Novel Intermittent Dieting Strategies to Attenuate Adaptive Responses to Energy Restriction. Obes. Rev.19:47–60.
  26. Pierre K, Pellerin L, (2005). Monocarboxylate transporters in the central nervous system: distribution, regulation and function. J Neurochem. 94(1):1–14
  27. Jensen NJ, Wodschow HZ, Nilsson M, et al (2020). Effects of Ketone Bodies on Brain Metabolism and Function in Neurodegenerative Diseases. Int J Mol Sci. 21(22):8767.
  28. Singh I, Bhat S, Tamatta R, et al (2026). Interplay Between Autophagy, Cellular Senescence, and Brain Aging: Neuroprotective Implications of Intermittent Fasting. Cell Mol Neurobiol. 46(1):75.
  29. Jenkins D. (2025). Metabolic Effects of Intermittent Fasting: Insights from Clinical Trials. J Clin Nutr Metab 2025, 9:1.
  30. Shalabi H, Hassan AS 4th, Al-Zahrani FA, et al. (2023). Intermittent Fasting: Benefits, Side Effects, Quality of Life, and Knowledge of the Saudi Population. Cureus. 15(2):e34722.
  31. Jackson JM, Blaine D, Powell-Tuck J, et al. (2006). Macro- and micronutrient losses and nutritional status resulting from 44 days of total fasting in a non-obese man. Nutrition. 22(9):889-97.
  32. Conn MO, Marko DM, Schertzer JD. (2024). Type 2 Diabetes Alters Metabolic Fuel Selection During Intermittent Fasting. J Endocr Soc. 8(Suppl 1):bvae163.984.
  33. Paulussen KJM, McKenna CF, Beals JW, et al. (2021). Anabolic Resistance of Muscle Protein Turnover Comes in Various Shapes and Sizes. Front Nutr. 8:615849.
  34. Williamson E, Moore DR. (2021). A Muscle-Centric Perspective on Intermittent Fasting: A Suboptimal Dietary Strategy for Supporting Muscle Protein Remodeling and Muscle Mass? Front Nutr. 8:640621
  35. Blumberg J, Hahn SL, Bakke J. (2023). Intermittent fasting: consider the risks of disordered eating for your patient. Clin Diabetes Endocrinol. 9(1):4.
  36. Sebastian SA, Shah Y, Arsene C. (2024). Intermittent fasting and cardiovascular disease: A scoping review of the evidence. Dis Mon. 70(11):101778

About the Author: Giuliana Rocca, ANutr

Giuliana is a Programme Manager in University College Dublin. She delivers nutrition workshops and mentors in cooking programmes, providing advice on sustainable diets and healthy food choices to individuals, families and communities.

Leave A Comment

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