Intermittent fasting has become a popular weight loss strategy in recent years. Many studies claim that this eating pattern not only helps with weight loss, but also improves metabolism and heart health. Discover an expert’s insights on the fasting diet, its potential health benefits, and possible side effects.
Intermittent fasting involves alternating periods of fasting and eating. A commonly used method is timed eating, where individuals follow the 16/8 method (fasting for 16 hours and then eating within an eight-hour window) or the 14/10 method (fasting for 14 hours followed by a 10-hour eating window). There are also other approaches such as alternate day fasting, fasting twice a week, and fasting once a week for 24 hours.
Benefits of Intermittent Fasting
„Some preliminary studies suggest that intermittent fasting may contribute to metabolic health due to its effects on insulin sensitivity and blood sugar regulation. Others have found that intermittent fasting may aid in cell repair due to increased autophagy, a process where cells remove damaged components,“ Michelle Routhenstein, a registered dietitian and preventive cardiology nutritionist and owner of Entirely Nourished, told Medical news.
„However, further long-term studies are needed to assess the true benefits of intermittent fasting in the long run. The long-term effects of intermittent fasting on metabolism, hormone balance, and overall health are still subjects of ongoing research, and comprehensive conclusions are being drawn,“ she added.
Intermittent fasting is viewed by many as an effective weight loss method, as it usually allows people to consume fewer meals, helping reduce their overall calorie intake. Additionally, the fasting diet promotes hormone functions such as insulin regulation, critical for effective weight loss.
A 2020 study suggests it may help with weight loss ranging from 0.8% to 13.0% of initial body weight.
Blood Sugar Control
In addition to weight loss benefits, some studies indicate that intermittent fasting may help reduce insulin resistance and blood sugar levels. Results from a small 2022 study even suggest it may aid in diabetes remission.
However, intermittent fasting is not generally recommended for people with type 2 diabetes. Those undergoing diabetes treatment may need to adjust their medications if they want to try timed eating. It is always advisable for diabetics to consult a doctor before changing their eating habits.
A 2019 research review published in the National Library of Medicine examined the effects of intermittent fasting on the cardiovascular system. The study found that intermittent fasting may help lower total cholesterol, triglycerides, and LDL cholesterol, while also lowering both systolic and diastolic blood pressure – key factors influencing heart health.
According to Routhenstein, the most common side effects of intermittent fasting include hunger, irritability, headaches, fatigue, nutrient deficiencies, and potential impacts on sleep.
„Intermittent fasting may not be suitable for individuals with certain conditions, including diabetes, cardiovascular problems, gastrointestinal disorders, kidney disease, thyroid disorders, mental health conditions, and those taking certain medications. Medications may require consistent food consumption for proper absorption and fasting may affect their effectiveness,“ she warned.
It is also not recommended for pregnant and breastfeeding women, underweight individuals, people with a history of eating disorders, those with low blood sugar (hypoglycemia), and individuals diagnosed with end-stage liver disease.
Routhenstein recommends consulting with a healthcare professional, such as a registered dietitian, before starting the diet. „They will assess your health status, medication needs, and potential interactions with fasting practices, and develop tailored recommendations to promote your optimal health,“ she explained.
Choosing a Fasting Plan
According to a recent large-scale study, restricting food intake to a 10-hour window per day reduces hunger and improves mood and energy. The study also found that individuals who consistently adhered to this eating window experienced greater benefits than those who alternated daily.
However, Routhenstein recommends choosing a personalized fasting plan with long-term sustainability in mind. „When selecting a fasting plan, prioritizing long-term sustainability is important. Opting for a very short fasting window may lead to nutrient deficiencies and high metabolic stress, and may potentially have negative effects on cardiometabolic health. If you are taking medications that require food intake, it is best to refrain from fasting during those times to ensure their effectiveness,“ she said.
„A recent study has shown that delaying the first meal of the day by an hour is associated with an increased risk of overall cardiovascular diseases, highlighting the importance of the timing window for intermittent fasting’s application,“ she added.