We've been told never to skip a meal — but it turns out food restriction may offer a host of health benefits from improving inflammatory markers to enhancing memory.
Right now, fasting is in the spotlight more than ever before. This isn't just because Muslims from around the world will be fasting for Ramadan, which takes place from May 15–June 15, but also because intermittent fasting has become a popular wellness trend for its weight loss benefits — and so much more.
Whether you're fasting for religious reasons or looking for a new feel-good trend to try, food restriction can make a positive impact on your health. Here's what you need to know:
What does fasting entail exactly?
Simply put, fasting is abstaining from food and drink. However, the way fasting is done can vary depending on the goals and purpose. Ben Sit, Registered Dietitian and Founder of Evolved Sport and Nutrition, explains that there are four different types of fasting, which include:
- Time restricted intermittent fasting (only eating between certain hours of the day)
- Alternate day fasting (no food intake for 24 hours every other day)
- Multiple day fasting (not eating for multiple days followed by unrestricted eating when the fast is broken)
- Religious fasting (various fasting regimens for religious reasons, such as Muslims avoiding food and drink from dawn to sunset daily for the month of Ramadan)
What are the health benefits of fasting?
The research on intermittent fasting includes a combination of animal studies and human studies and looking at different types of fasting. While there have been mixed findings, there are some promising health benefits to fasting:
- Fasting has shown to help with weight loss, primarily due to calorie restriction. Sit explains that fasting results in changes in the body’s sensitivity to hormones that affect hunger and the feeling of fullness.
- Fasting may help improve cardiovascular health through improvements in HDL cholesterol and triglycerides. There have been some mixed findings on whether fasting increases or decreases LDL cholesterol, which is known as the bad cholesterol.
- Research has shown that fasting significantly improves inflammatory markers Improvements in inflammatory markers, including C-reactive protein, tumour necrosis factor-alpha, adiponectin, leptin and brain-derived neurotrophic factor.
- Limited studies have also found decreases in fasting insulin and fasting blood glucose. However, there have been other studies showing an increase in fasting blood glucose levels as well.
- Fasting has also shown to have cognitive benefits, such as improved memory.
There is still research needed to further explore these effects and to better understand the long-term effects of fasting on the body.
What foods should you eat during non-fasting hours for the greatest health benefits?
Some suggest fasting should be followed by unrestricted eating, but ensuring you are eating balanced and wholesome meals during non-fasting hours can amplify the health benefits of food restriction. A potential drawback of intermittent fasting is the lack of emphasis on calories and portion sizes during non-fasting hours. Especially if your goal is weight loss, Sit says that studies that compare intermittent fasting to other weight loss methods show similar weight loss results only when caloric intake is matched.
To ensure you're adequately nourished and don’t overeat during your non-fasting hours, choose these five foods:
- Protein sources such as fish, chicken and lentils (they're essential to prevent muscle loss)
- Whole grain carbohydrates such as whole grain bread, oatmeal and quinoa (they help provide a sustained source of energy from carbohydrates that won’t spike your blood sugar levels when eating)
- Healthy fats such as avocado, nuts and seeds (they help provide sources of unsaturated fat and also help with satiation)
- Vegetables and fruit (they'll provide fibre as well as a variety of vitamins and minerals)
- Adequate amounts of water (it's important for hydration)
If you are interested in intermittent fasting, speak to a dietitian to ensure you are doing it safely, minimizing side effects and reaping the benefits.