6 Types of Intermittent Fasting & Food to Eat While Fasting

Intermittent fasting (IF) is currently one of the world’s top trends for quick weight loss. Individuals turn to this eating pattern to shed kilos while improving their fitness and simplifying their lifestyle.

Unlike traditional calorie restriction methods, intermittent fasting (IF) focuses on when rather than what you eat. This approach cycles between periods of eating and fasting, offering various protocols to suit individual preferences and lifestyles.

This comprehensive guide is here to provide everything that you need to know about IF. Keep reading!

Unlike most weight-loss diets, intermittent fasting dictates one on ‘when to eat’ and not ‘what to eat’. It is an eating pattern that revolves around voluntary fasting and eating. 

Intermittent fasting means cycling between periods of eating and fasting, typically involving designated hours or days of calorie restriction. Therefore, this method includes a 16-hour or 24-hour fast twice a week.

If you are completely healthy with no underlying disease and want to start intermittent fasting, learn about its following benefits -

• Boosts Cellular Functionality: Whenever you fast, the insulin level in your blood drops, promoting weight loss. It also helps flush out toxins from your cells, known as autophagy. IF also brings about genetic changes, such as improving longevity.
• Lowers the Risk of Developing Diabetes: Intermittent fasting effectively reduces insulin resistance, reducing the risk of developing type 2 diabetes.
• Reduces Oxidative Stress: The development of free radicals in the body damages the body's essential proteins and DNA. IF improves the body's resistance to oxidative stress and fights inflammation to protect it from diseases.
• Improves Brain Health: Intermittent fasting helps increase a hormone named brain-derived neurotrophic factor or abrineurin. An increase in BDNF reduces the risk of developing depression and other brain damage due to strokes.
• Extends Lifespan: According to a study published in Harvard Gazette, IF regulates mitochondrial networks and leads to healthy ageing.
• Cellular Repair Processes: Fasting triggers autophagy, where cells remove damaged components. By promoting cellular repair, intermittent fasting may contribute to a healthy life.
• Reduced Inflammation: Intermittent fasting can decrease levels of inflammatory markers. Reduced inflammation benefits conditions like arthritis and asthma.
• Hormone Regulation: Intermittent fasting can significantly increase human growth hormone levels. Higher growth hormone levels help in muscle gain and fat loss, boosting metabolism.
• Improved Digestion: Fasting gives the digestive system a break, improving digestion efficiency. It helps balance gut bacteria, enhancing gut health.
• Enhanced Metabolic Rate: Short-term fasting can increase metabolic rate, aiding in weight management. Enhanced metabolism results in more consistent energy levels throughout the day.
• Heart Health: Fasting can lower LDL cholesterol and triglycerides. It may also help reduce blood pressure, improving overall cardiovascular health.

Therefore, it is safe to say that intermittent fasting is healthy for you.

There are various types of IF. So, we suggest that you take some time to select the one that suits you best. Listed below are some of the popular schedules for intermittent fasting -

• 5:2 Fasting – In this method, you consume 500 to 600 calories twice a week. Then, you will continue your regular diet for the rest of the week.
• 16/8 – It involves time restriction. You need to skip your breakfast and restrict eating to 8-hours. For instance, you can choose to have your meals between 1 pm and 9 pm. Then, you will fast for a period of 16 hours.
• 24-Hour Regime – Popularly known as “Eat-Stop-Eat,” it involves fasting for 24-hours once or twice a week.
• Warrior Diet – This diet encourages you to eat whole foods other than processed ones. It involves eating raw fruits and vegetables during the day and consuming a substantial proportion of meals at night.
• Meal Skipping- This method involves skipping one or two meals in a day when you are not feeling hungry. But remember to fill yourself with healthy and balanced meals during the non-fasting time.
• Alternate Day Fasting – As the name suggests, you need to fast every alternate day. There are variations in this method. You may consume 500 calories during fasting days. That said, health experts do not recommend this method as you may end your day with an empty stomach, which is not a healthy approach to weight loss.

The schedules mentioned above will help you to limit your calorie intake. However, make sure to not indulge in over-consumption of a high-calorific diet to substantiate starvation.

Intermittent fasting reduces calorie intake. It also lowers insulin levels, boosts human growth hormones, and increases norepinephrine. This facilitates the breakdown of fat in your body and increases its metabolism.

Note some of the following studies to understand whether IF helps with weight loss or not:

In a 2020 study by the Jama Network, individuals following the 16/8 schedule showed no significant difference in weight loss. However, a 12-week study showed substantial evidence of loss of muscle mass.

Only 69% of the participants remained fasting on the alternate fasting day. On the other hand, the 5:2 schedule showed substantial weight loss and lowered insulin levels in women.

Key Takeaway: The effectiveness of intermittent fasting for weight loss depends on your chosen schedule, lifestyle, and eating habits. Additionally, choosing a fasting schedule that fits your body the most is imperative. This makes your dietary habit sustainable and yields practical results in the long run.

Here is a list of foods that you must include during IF -

Lean Protein - It helps you to build and maintain muscle. Here are some of the top sources of lean protein -

Intermittent fasting requires careful attention to avoid counterproductive foods and habits that can undermine its benefits. Focusing on nutrient-dense foods while avoiding certain items can enhance the effectiveness of your fasting regimen.

• Sugary Foods and Drinks: Sweets, sodas, and high-sugar snacks can spike insulin levels, disrupting the fasting cycle and hindering fat loss.
• Refined Carbohydrates: White bread, pasta, and pastries can lead to rapid glucose fluctuations, making fasting periods more difficult to manage.
• Processed Foods: Fast foods, pre-packaged snacks, and processed meats often contain high levels of unhealthy fats and sodium, which can negate the health benefits of fasting.
• Alcoholic Beverages: Consuming alcohol, especially during fasting periods, can impair liver function and metabolism, reducing the effectiveness of the fasting process.
• Caloric Beverages: Juices, energy drinks, and smoothies can add unnecessary calories that break the fast and interfere with metabolic benefits.

When engaging in intermittent fasting, selecting the right exercises is crucial to maintain energy levels, support weight loss, and enhance overall fitness without compromising the fasting benefits. Here are practical exercises tailored to complement intermittent fasting.

• Low-Intensity Steady-State (LISS) Cardio: Walking, cycling, or swimming steadily for extended periods helps burn fat without depleting energy levels excessively, making it ideal during fasting.
• Strength Training: Lifting weights or resistance bands supports muscle maintenance and growth. Performing short sessions with moderate weights can improve strength and prevent muscle loss without causing extreme fatigue.
• High-Intensity Interval Training (HIIT): Engaging in short bursts of high-intensity exercises followed by rest periods can maximise calorie burn and boost metabolism. Sessions should be brief (15-20 minutes) to prevent overexertion.
• Yoga and Stretching: These exercises enhance flexibility, reduce stress, and improve circulation. Practices like Vinyasa or Hatha yoga offer a gentle yet effective workout suitable for fasting periods.
• Bodyweight Exercises: Push-ups, squats, and planks can build muscle and improve endurance. These versatile exercises can be adjusted to match your energy levels during fasting windows.

Intermittent fasting is ideal for individuals seeking a straightforward approach to enhancing their health, managing weight, and boosting metabolic functions. It’s especially effective for those who prefer structured eating patterns and are interested in the benefits of cellular repair and longevity. 

• Healthy Adults: Individuals without underlying medical conditions often find intermittent fasting beneficial for weight management, metabolic health, and overall well-being.
• People Seeking Weight Loss: Those aiming to reduce body fat and improve body composition may benefit from intermittent fasting due to its potential to enhance metabolic rate and control calorie intake.
• Individuals Looking to Simplify Eating Habits: Those who prefer structured eating patterns may find intermittent fasting simplifies meal planning and reduces the need for constant calorie counting.
• People with Stable Metabolic Health: Individuals without issues like hypoglycaemia or metabolic disorders can often manage fasting periods without adverse effects, making IF a viable option.
• Those Interested in Cellular Health: People looking to enhance cellular repair and longevity may be attracted to intermittent fasting due to its potential benefits related to autophagy and reduced oxidative stress.

Intermittent fasting (IF) can offer numerous health benefits but is unsuitable for everyone. While it may be an effective approach for many, certain individuals should avoid it due to specific health conditions or lifestyle factors. Here’s a detailed overview of who should not consider intermittent fasting.

• Pregnant or Breastfeeding Women: These individuals require consistent nutrient intake to support their health and that of their baby, making intermittent fasting inappropriate and potentially harmful.
• Individuals with Eating Disorders: Those with a history of eating disorders, such as anorexia or bulimia, should avoid intermittent fasting to prevent triggering disordered eating patterns.
• People with Certain Chronic Health Conditions: Patients with conditions like diabetes or cardiovascular disease should consult their healthcare provider before attempting intermittent fasting, as it can impact blood sugar levels and overall health.
• Adolescents and Growing Children: Young individuals need steady nutrient intake for growth and development, making fasting unsuitable and potentially detrimental.
• Individuals with Medication Requirements: Those who need to take medications with food or at specific times may find intermittent fasting complicates their regimen and interferes with treatment effectiveness.

While intermittent fasting (IF) can offer various health benefits, it may also lead to side effects and pose risks, especially when not approached with caution. Awareness of these potential issues can help manage and mitigate adverse outcomes.

• Hunger and Cravings: Extended fasting periods can lead to intense hunger, increased cravings, and potential overeating during eating windows, making it challenging to maintain a balanced diet.
• Fatigue and Weakness: Reduced calorie intake during fasting may cause low energy levels, fatigue, and general weakness, particularly when starting out or during strenuous activities.
• Headaches and Dizziness: Fasting can trigger headaches or dizziness due to fluctuations in blood sugar levels and dehydration, impacting daily functioning.
• Sleep Disturbances: Some individuals may experience insomnia or disrupted sleep patterns, as changes in eating schedules can affect circadian rhythms.
• Digestive Issues: Intermittent fasting might cause gastrointestinal problems such as bloating, constipation, or nausea, mainly if large meals are consumed after fasting.
• Nutritional Deficiencies: Inadequate planning during eating windows can lead to deficiencies in essential nutrients, impacting overall health and well-being.

While intermittent fasting can be beneficial, it is essential to take precautions to ensure your health and well-being are not compromised during fasting periods. Adhering to these precautions can help you navigate intermittent fasting safely and effectively.

• Stay Hydrated: Drink adequate water throughout the fasting period to prevent dehydration and support bodily functions.
• Monitor Energy Levels: Pay attention to your body's signals and adjust fasting durations or intensity of activities accordingly to avoid fatigue or overexertion.
• Maintain Nutritional Balance: During eating windows, focus on nutrient-dense foods to meet your body's requirements and prevent deficiencies.
• Listen to Your Body: If you experience adverse effects such as dizziness, headaches, or extreme hunger, consider modifying your fasting approach or seeking guidance from a healthcare professional.
• Avoid Overeating: While breaking your fast, practice mindful eating and avoid consuming excessive amounts of food to prevent digestive discomfort and weight gain.

According to the New England Journal of Medicine, IF can help one deal with obesity, diabetes, and cardiovascular diseases. Moreover, as per Harvard, there is no substantial difference in heart rate, total cholesterol level, etc.

So, certain pitfalls that you need to look for are as follows -

• This eating pattern is unsuitable for individuals habituated to eating every few hours.

• Patients with diabetes should not observe intermittent fasting to avoid metabolic disturbances.

• Prolonged fasting may lead to unhealthy behaviour, such as overeating, to substantiate the fasting.

You must also note here that individuals with the following health conditions must abstain from IF -

• Pregnant Women

• Individuals Under Medication

• Adolescents

• People With Eating Disorders (anorexia or bulimia nervosa)

Individuals with no underlying disease can easily try intermittent fasting to stay healthy. Expert nutritionists recommend not following IF to lose weight. That said, individuals suffering from a chronic health issue must consult a doctor before making a dietary change.

Intermittent fasting is a powerful dietary approach that offers a wide range of health benefits, from weight loss and improved metabolic health to enhanced brain function and potential cancer prevention. By incorporating periods of fasting into your routine, you can significantly improve insulin sensitivity, reduce inflammation, and promote cellular repair processes.