Intermittent Fasting Explained: Health Benefits and How to Start
Intermittent fasting isn’t just another fad—it’s a game-changer for your metabolic health. We’re talking about a powerful, time-restricted eating strategy that goes beyond weight management. It’s about mastering your blood sugar, slashing inflammation, and fortifying your body against chronic diseases like diabetes. Ready to unlock the full potential of intermittent fasting? Let’s dive in.
What is Intermittent Fasting?
For centuries, people have practiced various forms of fasting, often tied to religious or cultural traditions like Ramadan or Lent. But let’s get real—intermittent fasting is a whole different ballgame. Unlike traditional fasting, which means going without food for days, intermittent fasting is a smarter, more sustainable approach. It’s all about alternating between periods of eating and fasting, giving your body the break it needs to function at its best. Whether you’re aiming to shed pounds, lower your blood pressure, or keep your blood sugar in check, this method has got you covered.
5 Benefits of Intermittent Fasting
Intermittent fasting isn’t just another diet—it’s a well-researched approach with proven benefits. From boosting brain health to protecting your heart and improving digestion, here’s why intermittent fasting could be the key to your health transformation:
1. Supercharge Weight Loss
Constant meals and snacks lead to a continuous release of insulin, the metabolic hormone that regulates blood sugar levels. But here’s the kicker—insulin also stimulates fat storage. That’s why those snacks are doing you no favors when it comes to weight gain. During fasting periods, your blood sugar levels stay stable, reducing insulin release and giving you better control over your weight. Fasting pushes your body into ketosis, the metabolic state where fat becomes your primary fuel source instead of sugar. This can lead to significant weight loss without the need for strict calorie counting. A study in the Journal of Translational Medicine found that intermittent energy restriction from fasting was just as effective as continuous calorie restriction in promoting weight loss and improving metabolic health.
2. Boost Insulin Sensitivity
A diet heavy in carbs, processed foods, and sugar can lead to insulin resistance—a metabolic disaster where your body stops responding to insulin’s attempts to lower blood sugar. This forces your pancreas to pump out even more insulin, worsening insulin resistance and messing up your blood sugar control. Insulin resistance, also known as metabolic syndrome, opens the door to a host of health problems, including type 2 diabetes, polycystic ovary syndrome (PCOS), and cardiovascular diseases. A large systematic review and meta-analysis published in the International Journal of Endocrinology found that intermittent fasting significantly improved fasting glucose and insulin levels in people with metabolic syndrome.
3. Kickstart Cellular Repair
Intermittent fasting can trigger autophagy—a biological process where your body recycles damaged cellular components to generate energy and allow for cellular repair. Autophagy helps eliminate malfunctioning cells and supports healthy inflammatory responses, reducing the risk of cancer and autoimmune conditions. Autophagy kicks in when blood sugar and glycogen stores are depleted, which can be achieved by fasting for 16-18 hours. Pair intermittent fasting with a low-carb ketogenic diet to keep blood sugar and glycogen levels low, accelerating your journey into autophagy.
4. Slash the Risk of Chronic Diseases
Fasting has been found to reduce inflammation throughout the body, including the brain and gastrointestinal tract. Chronic inflammation is a known risk factor for numerous serious health conditions, including heart disease, diabetes, cancer, and neurodegenerative disorders. A study published in Medicina explored the effects of fasting on managing ulcerative colitis, concluding that “inflammatory markers like CRP and calprotectin were significantly reduced after eight weeks of intermittent fasting.”
5. Supercharge Brain Health
Intermittent fasting is linked to a reduced risk of Alzheimer’s and Parkinson’s. Fasting helps prevent the formation of brain plaques and supplies ketones to the central nervous system. These organic acids are byproducts of fat metabolism and are a preferred fuel source for brain cells, supporting optimal cognitive function and memory. Research published in Nutrition Reviews found that prolonged periods of calorie restriction in animals reduced protein tangles in brain tissue associated with Alzheimer’s disease. The study also discovered that fasting improves neuronal health and cognitive function.
Here are five common types of intermittent fasting models.
1. The 16:8 Method
The 16:8 fasting method involves 16 hours of fasting followed by an eight-hour eating window. For example, you might have lunch at noon and dinner around seven, then fast until noon the next day. Other variations include the 18:6 and 20:4 methods, where you fast for 18 or 20 hours and have a six or four-hour eating window. These models achieve a prolonged fasting period that helps extend autophagy while maximizing the benefits of weight loss and cognitive improvements.
2. Alternate-Day Fasting
Alternate-day fasting is a form of intermittent fasting characterized by fasting every other day. The alternate-day fasting plan has two versions. The most common variant is zero-calorie fasting on fasting days. However, some dieters reduce their calorie intake to between 500 and 600.
3. One Meal a Day (OMAD)
One Meal a Day (OMAD) is a popular intermittent fasting model where the dieter eats only one meal per day. OMAD, also known as the 23:1 fasting method, involves fasting for 23 hours, followed by a one-hour eating window. Alternate-day OMAD is a more restrictive version that combines the 23:1 fasting with alternate-day fasting. It involves consuming one meal every two days to accelerate weight loss. Abstaining from eating on certain days of the week can be particularly beneficial for those with excess body weight or a sluggish metabolism.
4. Dry Fasting
Dry fasting is characterized by abstaining from both food and liquids for a short period, typically no more than a day. Dry fasts are classified into two groups: soft dry and hard dry. Soft dry fasts allow the use of water for activities like showering, brushing teeth, washing hands, or other hygiene or cleaning activities. In contrast, hard dry fasts prohibit any contact with water. Dry fasting can quickly become dangerous, as the body cannot survive without water for extended periods. However, intermittent dry fasting from dawn to dusk is common during Ramadan, and a study published in the Journal of Human Nutrition and Dietetics found that dry fasting helps reduce Body Mass Index (BMI) in healthy adults.
5. Prolonged Fasts
Prolonged fasts involve fasting from 24 hours to several days at a time, typically once a week or month. These fasts are designed to increase autophagy, which peaks around 48 hours of fasting, according to an animal study published in Cells. However, this fasting method is the most extreme and is not ideal for beginners. Refeeding after a prolonged fast must be carefully planned to avoid refeeding syndrome, a potentially serious condition that can cause heart palpitations, bloating, mood swings, and confusion. It’s crucial to consult a healthcare provider before practicing prolonged fasting to avoid negative health effects. This is especially important for people with pre-existing health conditions and those taking prescription medications.
Is Intermittent Fasting Safe?
When combined with a balanced diet, an intermittent fasting plan is safe for most people and has been shown to support healthy metabolic function and reduce the risk of disease. However, strict intermittent fasting can become dangerous without optimal nutrition or calorie intake. Consuming inadequate amounts of calories and nutrients can lead to unhealthy weight loss and nutrient deficiencies associated with mood disorders, dizziness, fatigue, and other adverse health effects.
Here are some considerations to ensure intermittent fasting is right for you.
Who Should Be Cautious or Avoid It?
While fasting is generally considered safe, pregnant or breastfeeding women should steer clear of intermittent fasting. Expectant mothers need extra nutrients and calories to support fetal development. Fasting could increase the risk of deficiencies linked to premature birth, lower IQ, and congenital disabilities. Those with a history of eating disorders should also avoid intermittent fasting to prevent a potential relapse into unhealthy eating habits. Additionally, individuals taking antidiabetic medications or insulin are at risk of dangerously low blood sugar levels during fasting. This could lead to cognitive problems, slurred speech, fatigue, and, in severe cases, seizures.
How to Start Intermittent Fasting
The goal of following an intermittent fasting eating pattern is to refrain from consuming high-calorie foods and beverages during fasting periods. If you’re new to intermittent fasting, it’s wise to start slow. This will allow your metabolism to adjust to the change in meal frequency. Three meals a day without snacks is a manageable first step for most dieters. As you become more comfortable with fasting and no longer experience hunger pangs, you can skip breakfast and eat just two meals a day using the 16:8 fasting method. Those with significant weight to lose may benefit from reducing the eating window to a 20:4 schedule or extending the fast to OMAD (One Meal a Day) or alternate-day OMAD.
Intermittent Fasting Tips and Troubleshooting
Many people new to intermittent fasting start too quickly, leading to impulsive behaviors like snacking or reverting to unhealthy eating habits. Here are four intermittent fasting tips to help you stay on track.
1. Avoid Snacking
One of the most common mistakes dieters make during intermittent fasting is snacking during the eating window. Even consuming low-calorie foods or snacks labeled as healthy can trigger insulin release, which interrupts fat burning and reduces the benefits of calorie restriction. Once your body adapts to the profound effects of intermittent fasting, you won’t feel hungry or need to snack between meals.
2. Limit Carbs and Increase Healthy Fats
Regular consumption of carbs like sugar, bread, pasta, sodas, or wine will make fasting more difficult. Carbs can cause significant insulin spikes and blood sugar fluctuations, leading to cravings and hunger pangs. In contrast, healthy fats found in olives, avocados, fatty fish, and nuts are satiating and help you fast longer. Bulletproof coffee is a great way to curb hunger and support energy levels without breaking your fast. Also known as keto coffee, bulletproof coffee contains black coffee, butter, and medium-chain triglyceride (MCT) oil. These pure fats don’t trigger insulin release and promote satiety without interfering with fat burning or autophagy. However, it’s essential to avoid calorie-containing drinks during fasting, such as sodas, fruit juices, milk, or coconut water.
3. Support Nutrient Levels
Without optimal nutrition, fasting can lead to nutrient deficiencies and electrolyte imbalances, causing weakness, fatigue, and irritability. Supplementation during fasting is vital to reduce the risk of depleting essential nutrients, especially when practicing OMAD or water fasting. Some of the best supplements for intermittent fasting include B vitamins, a trace mineral complex, and a sugar-free electrolyte powder rich in potassium.
4. Stay Hydrated
Exercising while fasting can promote weight loss, increase growth hormone levels, and boost autophagy. Despite its benefits, fasting during physical activity can lead to dizziness, lightheadedness, and other side effects when electrolyte levels are depleted. To replenish lost electrolytes and promote energy production, it’s crucial to stay hydrated using an electrolyte powder before, during, and after your workout. However, during fasting, avoid pre-workout powders containing branched-chain amino acids (BCAAs). BCAAs are proteins that can trigger insulin release and may break your fast.
How Long Does It Take to See Results?
Intermittent fasting can produce visible weight loss results within a few weeks. Dieters who stick to regimented fasting and eating periods can lose up to three pounds a week. A systematic review of studies published in the Canadian Family Physician found that intermittent fasting was as effective as calorie restriction for weight loss. The authors also discovered that intermittent fasting can help obese individuals with type 2 diabetes improve glycemic control. Those with significant weight to lose can burn six pounds a week. However, how much weight you can lose during fasting depends on your calorie intake and the fasting method used. OMAD and alternate-day OMAD are popular for rapid weight loss and help dieters tap into fat stores more efficiently.