Intermittent fasting: Its capabilities and limitations

Intermittent fasting (IF) is described as the intentional abstention from food for a specific period and has surged into the spotlight with almost a fad-like fervor; its advocates singing praises of numerous benefits. This piece sets out to untangle the scientific reality from the hype in this ancient practice. From changes in metabolism to potential boosts in cognitive function, we'll break down what IF genuinely offers and what lies outside its realm. The goal is to bring clarity to the influence of fasting on our overall health.

1. Metabolic changes:

What IF can do: IF can induce metabolic changes, such as improved insulin sensitivity and increased production of ketone bodies (Wang & Wu, 2022). This may contribute to better blood sugar control and fat utilisation for energy.

What IF cannot do: While IF can enhance metabolic flexibility, it is not a magic solution for weight loss on its own. Long-term weight management still requires a balanced diet and regular physical activity.

2. Cellular repair and autophagy:

What IF can do: IF triggers autophagy, a cellular repair process that removes damaged components (Erlangga et al., 2023). This has been associated with longevity and a lower risk of certain diseases.

What IF cannot do: IF alone cannot prevent all diseases, and its impact on longevity is complex. Lifestyle factors, genetics, and overall health play crucial roles.

3. Brain health:

What IF can do: IF has shown cognitive benefits, including improved brain function and reduced risk of neurodegenerative diseases. BDNF, a brain-derived neurotrophic factor, may increase during fasting, supporting brain health (Mattson et al., 2018).

What IF cannot do: IF is not a guaranteed shield against all cognitive decline. Factors like genetics, overall health, and other lifestyle choices also influence brain health.

4. Inflammation and immune system:

What IF can do: Some studies suggest that IF may reduce inflammation (Wang et al., 2020) and promote a healthy immune system by influencing the gut microbiota (Shi et al., 2021).

What IF cannot do: IF is not a cure for all inflammatory conditions. Chronic diseases may require comprehensive medical management.

5. Weight loss:

What IF can do: IF can lead to short-term weight loss by creating a calorie deficit. Intermittent fasting, in particular, has gained attention for its potential in weight management (Welton et al., 2020).

What IF cannot do: Longer-term research is needed to understand the sustainable role IF can play in weight loss. Sustainable weight loss also requires a balanced, nutrient-dense diet and regular physical activity. Long-term success involves a holistic approach.

IF can offer several health benefits, from metabolic improvements to cellular repair processes. However, it is not a one-size-fits-all solution and cannot replace a comprehensive approach to health, including a balanced diet, regular exercise, and other lifestyle factors. Before embarking on any fasting regimen, it's crucial to consult with a healthcare professional, especially for those with existing health conditions. Understanding the science behind fasting allows individuals to make informed decisions about incorporating it into their overall wellness strategy.

Erlangga, Z., Ghashang, S. K., Hamdan, I., Melk, A., Gutenbrunner, C., & Nugraha, B. (2023). The effect of prolonged intermittent fasting on autophagy, inflammasome and senescence genes expressions: An exploratory study in healthy young males. Human Nutrition & Metabolism, 32, 200189. https://doi.org/10.1016/j.hnm.2023.200189.

Mattson, M. P., Moehl, K., Ghena, N., Schmaedick, M., & Cheng, A. (2018). Intermittent metabolic switching, neuroplasticity and brain health. Nature Reviews Neuroscience, 19, 81–94. https://doi.org/10.1038/nrn.2017.156

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 Medecin de Famille Canadien, 66(2), 117–125.

Shi, H., Zhang, B., Abo-Hamzy, T., Nelson, J. W., Ambati, C. S. R., Petrosino, J. F., Bryan, R. M., Jr, & Durgan, D. J. (2021). Restructuring the gut microbiota by intermittent fasting lowers blood pressure. Circulation Research, 128(9), 1240–1254. https://doi.org/10.1161/CIRCRESAHA.120.318155

Wang, X., Yang, Q., Liao, Q., Li, M., Zhang, P., Santos, H. O., Kord-Varkaneh, H., & Abshirini, M. (2020). Effects of intermittent fasting diets on plasma concentrations of inflammatory biomarkers: A systematic review and meta-analysis of randomized controlled trials. Nutrition (Burbank, Los Angeles County, Calif.), 79-80, 110974. https://doi.org/10.1016/j.nut.2020.110974

Wang, Y., & Wu, R. (2022). The effect of fasting on human metabolism and psychological health. Disease markers, 2022, 5653739. https://doi.org/10.1155/2022/5653739