Intermittent fasting has been used for centuries for religious reasons, and it has become a very popular tool for weight loss in recent years. Followers of this dietary approach enjoy the flexibility of being able to choose when and how to fast, and the fact it only requires calorie restriction on fasting days helps many patients continue with this approach for longer than they would with a traditional diet involving daily restriction. Overall, patients tend to feel less deprived with fasting methods than more conventional plans, and they can still enjoy their favorite foods.
While studies show intermittent fasting is effective for weight loss and the reduction of insulin resistance, any type of fasting could pose risks if done improperly. The guide below outlines some key principles to keep in mind for safe fasting. Patients should, of course, ask their doctor before beginning a fasting regimen to ensure they are healthy enough to do so.
Some patients experience fatigue during a fast, and this can be exacerbated by dehydration. Most individuals get twenty to thirty percent of their daily fluid intake from the water naturally contained in the foods they eat, so it is especially important to stay hydrated on fasting days. Patients should aim to drink more fluids on fasting days than they would on non-fasting days. While water is best, herbal tea, black coffee, and calorie-free beverages all count for fluid intake. If participating in a modified fast such as the 5:2 diet, patients might wish to include juices or smoothies in their fluid intake for fasting days as well. Ideally, women should consume at least two liters of fluid on fasting days, and men are advised to consume a minimum of three liters. Patients should consume fluids whenever they feel thirsty, even if they have already consumed the recommended amount of fluid for the day. Keeping track of urine color can be useful in estimating hydration levels. If urine is dark yellow, this suggests the patient needs to drink more fluids, and pale yellow, nearly clear urine generally indicates the patient is sufficiently hydrated. Staying hydrated can help reduce hunger, and it may also reduce the headaches that sometimes occur during fasts.
Read about how to break a fast safely next.