Intermittent fasting
Intermittent fasting is a dieting method that has recently grown in popularity, with claims that it can support weight loss and metabolic health, and maybe even extend lifespan. It’s popular for offering guidance on when to eat, not what to eat. This makes it crucial that a fasting plan coincides with healthy eating.
Popular Methods of Intermittent Fasting
The most popular method is the 16/8 fast, where all your daily meals fit into an 8-hour window, while you fast for the remaining 16 hours. This can be as simple as skipping breakfast and then not eating anything after dinner.
Johns Hopkins neuroscientist Mark Mattson has studied intermittent fasting for 25 years. He says our bodies have evolved to go without food for many hours, or even several days. In prehistoric times, before humans learned to farm, they were hunters and gatherers who evolved to survive — and thrive — for long periods without eating. Mattson explains that after hours without food, the body exhausts its sugar stores and starts burning fat, a process he refers to as metabolic switching.
Getting Started with Intermittent Fasting
It’s important to check with your doctor before starting intermittent fasting. Once you get their go-ahead, the actual practice is simple. You can pick a daily approach, which restricts daily eating to a six- to eight-hour period each day. For instance, you may choose to try 16/8 fasting: eating for eight hours and fasting for 16. On this fast, people usually finish their evening meal by 8 p.m. and then skip breakfast the next day, not eating again until noon.
Another intermittent fasting plan, known as the 5:2 approach, involves eating regularly five days a week. For the other two days, you limit yourself to one 500–600 calorie meal.
Tips for Fasting
- Staying Hydrated: Drink lots of water and calorie-free drinks, such as herbal teas, throughout the day. This can help ensure you get enough electrolytes, sodium, and potassium chloride.
- Avoiding Thoughts of Food: Plan plenty of distractions on fasting days to avoid thinking about food, such as catching up on paperwork or going to see a movie.
- Resting and Relaxing: Avoid strenuous activities on fasting days, although light exercise such as yoga may be beneficial.
- Making Every Calorie Count: If the chosen plan allows some calories during fasting periods, select nutrient-dense foods that are rich in protein, fiber, and healthful fats. Examples include beans, lentils, eggs, fish, nuts, avocado, and unprocessed meats.
- Eating High-Volume Foods: Select filling yet low-calorie foods, which include popcorn, raw vegetables, and fruits with high water content, such as grapes and melon.
- Increasing Taste Without Calories: Season meals generously with garlic, herbs, spices, or vinegar. These foods are extremely low in calories yet full of flavor, which may help to reduce feelings of hunger.
- Choosing Nutrient-Dense Foods After Fasting: Eating foods that are high in fiber, vitamins, minerals, and other nutrients helps to keep blood sugar levels steady and prevent nutrient deficiencies. A balanced diet will also contribute to weight loss and overall health.
Benefits of Intermittent Fasting
Intermittent fasting may benefit heart health, reduce inflammation, and improve cell repair processes. It may also help burn fat. Many benefits are related to changes in hormones, cell function, and gene expression.
- Hormonal Changes: When you fast, insulin levels drop, and human growth hormone (HGH) increases. Your cells initiate important cellular repair processes and change which genes they express.
- Weight Loss: Intermittent fasting helps you eat fewer calories while boosting metabolism slightly. It’s an effective tool to lose weight and visceral fat.
- Reduced Insulin Resistance: Intermittent fasting can reduce insulin resistance and lower blood sugar levels, at least in men.
- Reduced Oxidative Damage: Studies show that intermittent fasting can reduce oxidative damage and inflammation in the body. This should have benefits against aging and the development of numerous diseases.