THE IMPACT OF INTERMITTENT FASTING ON WEIGHT REDUCTION AND METABOLIC PARAMETERS — CURRENT STATE OF KNOWLEDGE

Aleksandra Straszewska; Aleksandra Woźniak; Patrycja Sobantka; Szymon Mokrzecki; Matylda Król; Katarzyna Aleksandrowicz; Zofia Grodzka; Mateusz Meszka; Ewa Bełc; Karolina Brzezińska; Anna Mamach

doi:10.31435/ijitss.3(51).2026.6182

Authors

Aleksandra Straszewska Central Teaching Hospital of Medical University of Lodz, Pomorska 251, 92-213 Łódź, Poland https://orcid.org/0009-0003-6293-9689
Aleksandra Woźniak Norbert Barlicki University Clinical Hospital No. 1 in Łódź, Stefan Kopcinski 22 Street, 90-153: Łódź, Poland https://orcid.org/0009-0003-5382-1451
Patrycja Sobantka Central Teaching Hospital of Medical University of Lodz, Pomorska 251, 92-213 Łódź, Poland https://orcid.org/0009-0004-3128-5181
Szymon Mokrzecki Norbert Barlicki University Clinical Hospital No. 1 in Łódź, Stefan Kopcinski 22 Street, 90-153: Łódź, Poland https://orcid.org/0009-0005-8228-2711
Matylda Król Copernicus Memorial Hospital, Pabianicka ST. 62, 93-513 Lodz, Poland https://orcid.org/0009-0000-7759-4933
Katarzyna Aleksandrowicz Medical University of Lodz: Lodz, Łódź Voivodeship, Poland https://orcid.org/0009-0008-5935-8265
Zofia Grodzka Independent Public Health Care Complex named after Marshal Józef Piłsudski in Płońsk (SPZZOZ): Płońsk, Poland https://orcid.org/0009-0002-0904-810X
Mateusz Meszka Central Teaching Hospital of Medical University of Lodz, Pomorska 251, 92-213 Łódź, Poland https://orcid.org/0009-0001-6147-7000
Ewa Bełc University Clinical Hospital No. 2 of the Medical University of Lodz, Żeromskiego ST. 113, 90-549 Lodz, Poland https://orcid.org/0009-0004-0224-8162
Karolina Brzezińska Medical University of Lodz: Lodz, Łódź Voivodeship, Poland https://orcid.org/0009-0008-4403-6060
Anna Mamach Norbert Barlicki University Clinical Hospital No. 1 in Łódź, Stefan Kopciński 22 Street, 90-153: Łódź, Poland https://orcid.org/0009-0004-5934-8674

DOI:

https://doi.org/10.31435/ijitss.3(51).2026.6182

Keywords:

Intermittent Fasting, Obesity, Insulin Sensitivity, Metabolism, Time-Restricted Eating

Abstract

Background: Intermittent fasting (IF) has emerged as a widely investigated dietary strategy for the management of obesity and metabolic disorders. Increasing evidence suggests that periodic energy restriction may improve body weight and metabolic parameters associated with cardiovascular disease and type 2 diabetes.

Aim: This review aimed to summarize the current evidence regarding the effects of intermittent fasting on body weight reduction, glucose–insulin metabolism, lipid profile, blood pressure, and inflammatory markers.

Methods: A narrative review of the literature indexed in PubMed was conducted, focusing primarily on publications from 2020–2025, including randomized controlled trials, systematic reviews, umbrella reviews, and meta-analyses evaluating intermittent fasting in adults with overweight, obesity, metabolic syndrome, or type 2 diabetes.

Results: Current evidence indicates that IF may promote moderate weight reduction, decrease visceral adiposity, improve insulin sensitivity, reduce fasting glucose and triglyceride concentrations, and modestly lower blood pressure. Early time-restricted eating appears particularly beneficial due to its alignment with circadian rhythms. However, most studies demonstrate that IF does not significantly outperform conventional caloric restriction when total energy deficit is comparable.

Conclusions: Intermittent fasting represents a promising nutritional strategy for improving metabolic health, particularly in individuals with obesity and metabolic syndrome. Nevertheless, long-term adherence, dietary quality, and sustained energy deficit remain the primary determinants of clinical effectiveness. Further long-term randomized controlled trials are required to establish the optimal IF protocols and their long-term safety.

References

Liu, L., Chen, W., Wu, D., & Hu, F. (2022). Metabolic efficacy of time-restricted eating in adults: A systematic review and meta-analysis of randomized controlled trials. The Journal of Clinical Endocrinology & Metabolism, 107(12), 3428–3441. https://doi.org/10.1210/clinem/dgac570

Chen, Y. E., Tsai, H. L., Tu, Y. K., & Chen, L. W. (2024). Effects of different types of intermittent fasting on metabolic outcomes: An umbrella review and network meta-analysis. BMC Medicine, 22(1), 529. https://doi.org/10.1186/s12916-024-03716-1

Silva, A. I., Direito, M., Pinto-Ribeiro, F., Ludovico, P., & Sampaio-Marques, B. (2023). Effects of intermittent fasting on regulation of metabolic homeostasis: A systematic review and meta-analysis in health and metabolic-related disorders. Journal of Clinical Medicine, 12, 3699. https://doi.org/10.3390/jcm12113699

Manoogian, E. N. C., Chow, L. S., Taub, P. R., Laferrère, B., & Panda, S. (2022). Time-restricted eating for the prevention and management of metabolic diseases. Endocrine Reviews, 43(2), 405–436. https://doi.org/10.1210/endrev/bnab027

Lowe, D. A., Wu, N., Rohdin-Bibby, L., et al. (2020). Effects of time-restricted eating on weight loss and other metabolic parameters in women and men with overweight and obesity: The TREAT randomized clinical trial. JAMA Internal Medicine, 180(11), 1491–1499. https://doi.org/10.1001/jamainternmed.2020.4153

Cienfuegos, S., Gabel, K., Kalam, F., Ezpeleta, M., Wiseman, E., Pavlou, V., Lin, S., Oliveira, M. L., & Varady, K. A. (2020). Effects of 4- and 6-h time-restricted feeding on weight and cardiometabolic health: A randomized controlled trial in adults with obesity. Cell Metabolism, 32(3), 366–378.e3. https://doi.org/10.1016/j.cmet.2020.06.018

Thomas, E. A., Zaman, A., Sloggett, K. J., Steinke, S., Grau, L., Catenacci, V. A., Cornier, M. A., & Rynders, C. A. (2022). Early time-restricted eating compared with daily caloric restriction: A randomized trial in adults with obesity. Obesity, 30(5), 1027–1038. https://doi.org/10.1002/oby.23420

He, M., Wang, J., Liang, Q., Li, M., Guo, H., Wang, Y., Deji, C., Sui, J., Wang, Y. W., Liu, Y., Zheng, Y., Qian, B., Chen, H., Ma, M., Su, S., Geng, H., Zhou, W. X., Guo, X., Zhu, W. Z., . . . Shi, B. (2022). Time-restricted eating with or without low-carbohydrate diet reduces visceral fat and improves metabolic syndrome: A randomized trial. Cell Reports Medicine, 3(10), 100777. https://doi.org/10.1016/j.xcrm.2022.100777

Wilkinson, M. J., Manoogian, E. N. C., Zadourian, A., Lo, H., Fakhouri, S., Shoghi, A., Wang, X., Fleischer, J. G., Navlakha, S., Panda, S., & Taub, P. R. (2020). Ten-hour time-restricted eating reduces weight, blood pressure, and atherogenic lipids in patients with metabolic syndrome. Cell Metabolism, 31(1), 92–104.e5. https://doi.org/10.1016/j.cmet.2019.11.004

Świątkiewicz, I., Mila-Kierzenkowska, C., Woźniak, A., Szewczyk-Golec, K., Nuszkiewicz, J., Wróblewska, J., Rajewski, P., Eussen, S. J. P. M., Færch, K., Manoogian, E. N. C., Panda, S., & Taub, P. R. (2021). Pilot clinical trial of time-restricted eating in patients with metabolic syndrome. Nutrients, 13(2), 346. https://doi.org/10.3390/nu13020346

Świątkiewicz, I., Woźniak, A., & Taub, P. R. (2021). Time-restricted eating and metabolic syndrome: Current status and future perspectives. Nutrients, 13(1), 221. https://doi.org/10.3390/nu13010221

Kunduraci, Y. E., & Ozbek, H. (2020). Does the energy restriction intermittent fasting diet alleviate metabolic syndrome biomarkers? A randomized controlled trial. Nutrients, 12(10), 3213. https://doi.org/10.3390/nu12103213

van den Burg, E. L., van Peet, P. G., Schoonakker, M. P., van de Haar, D. E., Numans, M. E., & Pijl, H. (2023). Metabolic impact of intermittent energy restriction and periodic fasting in patients with type 2 diabetes: A systematic review. Nutrition Reviews, 81(10), 1329–1350. https://doi.org/10.1093/nutrit/nuad015

Lin, X., Guan, Y., Wu, G., Huang, J., & Wang, S. (2022). Time-restricted eating for patients with diabetes and prediabetes: A systematic review. Frontiers in Nutrition, 9, 1025919. https://doi.org/10.3389/fnut.2022.1025919

Sutton, E. F., Beyl, R., Early, K. S., Cefalu, W. T., Ravussin, E., & Peterson, C. M. (2018). Early time-restricted feeding improves insulin sensitivity, blood pressure, and oxidative stress even without weight loss in men with prediabetes. Cell Metabolism, 27(6), 1212–1221.e3. https://doi.org/10.1016/j.cmet.2018.04.010

Song, D. K., & Kim, Y. W. (2023). Beneficial effects of intermittent fasting: A narrative review. Journal of Yeungnam Medical Science, 40(1), 4–11. https://doi.org/10.12701/jyms.2022.00010

Welton, S., Minty, R., O'Driscoll, T., Willms, H., Poirier, D., Madden, S., & Kelly, L. (2020). Intermittent fasting and weight loss: Systematic review. Canadian Family Physician, 66(2), 117–125.

Tinsley, G. M., Forsse, J. S., Butler, N. K., Paoli, A., Bane, A. A., La Bounty, P. M., Morgan, G. B., & Grandjean, P. W. (2017). Time-restricted feeding in young men performing resistance training: A randomized controlled trial. European Journal of Sport Science, 17(2), 200–207. https://doi.org/10.1080/17461391.2016.1223173

Trepanowski, J. F., Kroeger, C. M., Barnosky, A., Klempel, M. C., Bhutani, S., Hoddy, K. K., Gabel, K., Freels, S., Rigdon, J., Rood, J., Ravussin, E., & Varady, K. A. (2017). Effect of alternate-day fasting on weight loss, weight maintenance, and cardioprotection among metabolically healthy obese adults: A randomized clinical trial. JAMA Internal Medicine, 177(7), 930–938. https://doi.org/10.1001/jamainternmed.2017.0936

Headland, M., Clifton, P. M., Carter, S., & Keogh, J. B. (2016). Weight-loss outcomes: A systematic review and meta-analysis of intermittent energy restriction trials lasting a minimum of 6 months. Nutrients, 8(6), 354. https://doi.org/10.3390/nu8060354

de Cabo, R., & Mattson, M. P. (2019). Effects of intermittent fasting on health, aging, and disease. The New England Journal of Medicine, 381(26), 2541–2551. https://doi.org/10.1056/NEJMra1905136

Longo, V. D., & Panda, S. (2016). Fasting, circadian rhythms, and time-restricted feeding in healthy lifespan. Cell Metabolism, 23(6), 1048–1059. https://doi.org/10.1016/j.cmet.2016.06.001

Rynders, C. A., Thomas, E. A., Zaman, A., Pan, Z., Catenacci, V. A., & Melanson, E. L. (2019). Effectiveness of intermittent fasting and time-restricted feeding compared to continuous energy restriction for weight loss. Nutrients, 11(10), 2442. https://doi.org/10.3390/nu11102442

Gabel, K., Hoddy, K. K., Haggerty, N., Song, J., Kroeger, C. M., Trepanowski, J. F., Panda, S., & Varady, K. A. (2018). Effects of 8-hour time restricted feeding on body weight and metabolic disease risk factors in obese adults: A pilot study. Nutrition and Healthy Aging, 4(4), 345–353. https://doi.org/10.3233/NHA-170036

Cho, Y., Hong, N., Kim, K. W., Cho, S. J., Lee, M., Lee, Y. H., Lee, Y. H., Kang, E. S., Cha, B. S., & Lee, B. W. (2019). The effectiveness of intermittent fasting to reduce body mass index and glucose metabolism: A systematic review and meta-analysis. Journal of Clinical Medicine, 8(10), 1645. https://doi.org/10.3390/jcm8101645

Anton, S. D., Moehl, K., Donahoo, W. T., Marosi, K., Lee, S. A., Mainous, A. G., III, Leeuwenburgh, C., & Mattson, M. P. (2018). Flipping the metabolic switch: Understanding and applying the health benefits of fasting. Obesity, 26(2), 254–268. https://doi.org/10.1002/oby.22065

Harvie, M., & Howell, A. (2017). Potential benefits and harms of intermittent energy restriction and intermittent fasting amongst obese, overweight and normal weight subjects—A narrative review of human and animal evidence. Behavioral Sciences, 7(1), 4. https://doi.org/10.3390/bs7010004

Varady, K. A. (2011). Intermittent versus daily calorie restriction: Which diet regimen is more effective for weight loss? Obesity Reviews, 12(7), e593–e601. https://doi.org/10.1111/j.1467-789X.2011.00873.x

Varady, K. A., & Hellerstein, M. K. (2007). Alternate-day fasting and chronic disease prevention: A review of human and animal trials. The American Journal of Clinical Nutrition, 86(1), 7–13. https://doi.org/10.1093/ajcn/86.1.7

Stockman, M. C., Thomas, D., Burke, J., & Apovian, C. M. (2018). Intermittent fasting: Is the wait worth the weight? Current Obesity Reports, 7(2), 172–185. https://doi.org/10.1007/s13679-018-0308-9

Harris, L., Hamilton, S., Azevedo, L. B., Olajide, J., De Brún, C., Waller, G., Whittaker, V., Sharp, T., Lean, M., Hankey, C., & Ells, L. (2018). Intermittent fasting interventions for treatment of overweight and obesity in adults: A systematic review and meta-analysis. JBI Database of Systematic Reviews and Implementation Reports, 16(2), 507–547. https://doi.org/10.11124/JBISRIR-2016-003248

Seimon, R. V., Roekenes, J. A., Zibellini, J., Zhu, B., Gibson, A. A., Hills, A. P., Wood, R. E., King, N. A., Byrne, N. M., & Sainsbury, A. (2015). Do intermittent diets provide physiological benefits over continuous diets for weight loss? A systematic review of clinical trials. Molecular and Cellular Endocrinology, 418, 153–172. https://doi.org/10.1016/j.mce.2015.09.014

Patterson, R. E., & Sears, D. D. (2017). Metabolic effects of intermittent fasting. Annual Review of Nutrition, 37, 371–393. https://doi.org/10.1146/annurev-nutr-071816-064634

Mattson, M. P., Longo, V. D., & Harvie, M. (2017). Impact of intermittent fasting on health and disease processes. Ageing Research Reviews, 39, 46–58. https://doi.org/10.1016/j.arr.2016.10.005

Chaix, A., Zarrinpar, A., Miu, P., & Panda, S. (2014). Time-restricted feeding is a preventative and therapeutic intervention against diverse nutritional challenges. Cell Metabolism, 20(6), 991–1005. https://doi.org/10.1016/j.cmet.2014.11.001

Hutchison, A. T., Regmi, P., Manoogian, E. N. C., Fleischer, J. G., Wittert, G. A., Panda, S., & Heilbronn, L. K. (2019). Time-restricted feeding improves glucose tolerance in men at risk for type 2 diabetes: A randomized crossover trial. Obesity, 27(5), 724–732. https://doi.org/10.1002/oby.22449

Parr, E. B., Devlin, B. L., Radford, B. E., & Hawley, J. A. (2020). A delayed morning and earlier evening time-restricted feeding protocol for improving glycemic control and dietary adherence in men with overweight/obesity: A randomized controlled trial. Nutrients.

Pureza, I. R. O. M., Macena, M. L., da Silva Junior, A. E., Praxedes, D. R. S., Vasconcelos, L. G. L., & Bueno, N. B. (2021). Effect of early time-restricted feeding on the metabolic profile of adults with excess weight: A systematic review with meta-analysis. Clinical Nutrition, 40(4), 1788–1799. https://doi.org/10.1016/j.clnu.2020.10.031

Simon, S. L., Blankenship, J., Manoogian, E. N. C., Panda, S., Mashek, D. G., & Chow, L. S. (2022). The impact of a self-selected time restricted eating intervention on eating patterns, sleep, and late-night eating in individuals with obesity. Frontiers in Nutrition, 9, 1007824. https://doi.org/10.3389/fnut.2022.1007824

Ng, G. Y., Kang, S. W., Kim, J., Alli-Shaik, A., Baik, S. H., Jo, D. G., Hande, M. P., Sobey, C. G., Gunaratne, J., Fann, D. Y., & Arumugam, T. V. (2019). Genome-wide transcriptome analysis reveals intermittent fasting-induced metabolic rewiring in the liver. Dose-Response, 17(3), 1559325819876780. https://doi.org/10.1177/1559325819876780