British dietitian Emer Delaney expressed that fasting creates significant self-control on the body and has various health benefits. Mentioning the positive effects of fasting on blood sugar levels and intestines, the expert supported her theories with some previous scientific research. According to Delaney, the best way to understand the impact of fasting is to think of the body like a hybrid car. In times when we’re not fasting, the body uses glucose derived from carbohydrates when consuming large meals, snacks, or drinks, but when fasting, the body’s fuel in the ‘gas tank’ of the liver and muscles begins to deplete.
Eight to twelve hours later, the body switches to ‘electric mode’ and starts using stored fats. This metabolic shift that enables fat burning is directed by several important processes. Blood sugar drops, insulin production decreases (this hormone instructs the body to store fat), and the liver begins to produce ketones. Ketones, derived from the breakdown of fat, are an extremely efficient fuel source for the brain and muscles. The body turns into a fat-burning machine, but this transition may not always be easy. The first few days of fasting can bring about extreme fatigue and hunger. This situation is related to the drop in blood sugar and the body’s adaptation to fat as the primary fuel source. Additionally, headaches due to dehydration might occur.
While fasting may result in getting a deep sleep on some nights, difficulty in falling asleep might be experienced on other nights. This outcome is related to the changes fasting creates on hormones regulating the sleep-wake cycle such as melatonin and cortisol.
Choosing foods that will keep you full and energetic during Ramadan is important. For suhoor, oatmeal prepared with nuts and fruits can be preferred. Avoiding sugary foods just before fasting begins is necessary because such foods can cause sudden fluctuations in blood sugar and hunger. Processed carbohydrates consumed at dinner may pave the way for digestive issues.
Managing water intake correctly is also crucial. The amount of water consumed throughout the day when not fasting should also be taken during fasting hours. It’s beneficial to avoid coffee and tea as they act as diuretics leading to fluid loss.
Scientists state that the body can adapt to fasting after about 5 days.
A study conducted in Australia in 2019 found that people who fasted during Ramadan lost a significant amount of weight and body fat. It was observed that the higher the initial body mass index (BMI), the more weight was lost. A study published in the European Journal of Clinical Nutrition in 2023 revealed positive effects of fasting on the intestines. The study found that fasting reduced bloating, pain, and acid reflux.
An investigation published in the American Heart Association Journal in 2021 showed that fasting could lower blood pressure. Fasting can also reduce inflammation. An analysis published in the Journal Of Nutrition And Intermediary Metabolism in 2018 examined the levels of cytokines, proteins that regulate inflammation in the body, in healthy adults before and after Ramadan. The research showed a significant decrease in cytokine levels among participants. Nevertheless, fasting may have some negative effects on overall health. Prolonged dehydration increases the risk of gallstones, and some individuals may regain weight by returning to their old habits after Ramadan.