What IS the DEAL with FASTING?!

Over the last couple of months, either in conversation with friends and family, or when working with new clients, questions about fasting have come up time and time again.

It is, in fact, one of the most common questions I get asked when somebody asks me what I do for a living!

I can save the others for another day, but all I can say this job title is much more of a conversation starter than saying “I work in Human Resources” which was my main career for 22 years!

This blog is designed to provide you with some basic information about fasting to help understand the different types of fasting we can do, as well as potential health benefits and considerations.

Why Fast?

From supporting metabolic health to promoting clarity and energy, fasting has been linked to a wide range of potential benefits.

Like any health approach, my approach with clients isn’t one-size-fits-all.

There are different methods available, things to think about like how fasting may differ for men and women (and yes, fasting at the right time for your cycle as a female is really important), and what you should consider when preparing for or ending a fast, especially from a nutritional perspective.

What is Fasting?

At its core, fasting is the voluntary abstention from food for a set period. While this might sound extreme, humans have fasted throughout history, traditionally due to seasonality, scarcity, hunter gatherers, or cultural and religious practices.

Today, many people choose to fast for health reasons. Research suggests that fasting may help:

• Improve insulin sensitivity

• Support weight management

• Reduce inflammation

• Enhance cellular repair through a process called autophagy

• Promote mental clarity and focus

  
  

However, fasting isn’t about deprivation - it’s about creating a balanced rhythm between eating and resting the digestive system.

There are several types of fasting, and choosing the right one depends on your goals, health status, whether you are male or female, lifestyle, and experience.

1. Intermittent Fasting (IF): This is the most popular and accessible form of fasting. Common methods include:

• 16:8: Fast for 16 hours, eat during an 8-hour window (e.g., 12pm–8pm). Personally I have got on very well with this type of fasting and it has supported weight loss and then weight maintenance. I don’t currently do 16:8 but it is something I will turn to when required and works for me. I explain a bit more later, but I have friends for example who have adopted this same protocol, and it hasn’t worked for them at all.

• 14:10 or 12:12: Gentler approaches, often good for beginners or those with hormonal concerns.

• 5:2: Eat normally five days a week and consume only 500–600 calories on the other two non-consecutive days. For me: this was hell!! For my husband, he was easily able to adopt 5:2 and suited him with great weight loss and improved energy.

  
  

2. Time-Restricted Eating (TRE)

Often used interchangeably with intermittent fasting, this method focuses more on aligning eating with the body’s circadian rhythm i.e. eating during daylight hours and fasting overnight.

3. Extended Fasts

Lasting 24 hours or longer these are considered extended fasts. These should be approached with care and preferably under the guidance of a healthcare practitioner.

4. Alternate-Day Fasting

This method alternates fasting days (where minimal calories are consumed) with eating days. While some find this effective, it can be harder to sustain and may impact energy levels or mood.

But is fasting just abstaining from food?

Not always…..

Fasting can take many forms, but two of the most talked-about methods are water fasts and juice fasts. While both aim to give the digestive system a rest and support detoxification, they differ in intensity, nutritional content, and suitability for different individuals.

Water Fasting

A water fast involves consuming only water i.e. no calories, no food, and generally no other beverages (sometimes herbal teas). It's the most restrictive form of fasting and is often done for 24-72 hours, though some people attempt longer fasts under medical supervision.

Pros:

• Promotes autophagy (cellular clean-up) more quickly due to complete calorie absence.

• May improve insulin sensitivity and reduce inflammation.

• Gives the digestive system a full rest.

Considerations:

• Very demanding on the body, especially for beginners.

• Not suitable for those with blood sugar issues, low body weight, or high stress levels.

• Can cause fatigue, dizziness, irritability, and low blood pressure.

• Should only be done under professional guidance, particularly if extended beyond 24 hours.

Best for: Experienced fasters or those under clinical supervision looking for a short-term reset.

Juice Fasting

Juice fasting involves consuming only fruit and vegetable juices for a set period. This is typically 1 to 3 days. It provides calories, vitamins, minerals, and antioxidants while avoiding solid food.

Pros:

• Easier to tolerate than water fasting.

• Supports liver detoxification with nutrients like vitamin C, glutathione precursors, and phytonutrients.

• Maintains blood sugar and energy levels more effectively than a water fast.

• Can support hydration and fibre (if using whole vegetable smoothies rather than strained juices).

Considerations:

• Can still cause blood sugar swings, especially if juices are high in fruit and low in fibre/protein.

• Not ideal for longer-term use, as it lacks adequate protein and fat.

• May not induce full autophagy benefits like water fasting.

• Wow, from my own experience if you are juicing yourself, it feels like you are forever cleaning the juicer if you have one and washing and chopping! It can actually be quite expensive buying the amount of fruit and veg (especially organic) you may need to buy to do this. I also found I was super hungry at certain times of the day in a bit of a crash and energy type of situation. I may have bailed on my last one halfway through and grabbed a sandwich at a petrol station as I thought I was about to pass out and just listened to my body - but this isn’t everybody’s experience.

  
  

Best for:

Beginners or those wanting a gentler introduction to fasting. It’s also a useful short-term strategy for people looking to increase plant-based nutrients and reduce processed food intake.

Fasting for Men v Women

Men and women often respond differently to fasting, largely due to hormonal differences.

Men generally tolerate fasting well and may even see quicker improvements in metabolic markers. Their hormones tend to be more stable throughout the month, allowing for a more straightforward approach to fasting.

Women, especially those of reproductive age, need to be more mindful. Fasting can influence key hormones like oestrogen and progesterone, and in some cases may lead to disrupted cycles or thyroid imbalances if done too aggressively.

Some guidelines for women:

• Start with gentle fasting windows (12:12 or 14:10).

• Avoid fasting during the late luteal phase of the menstrual cycle, when the body requires more fuel.

• Prioritise nourishment, sleep, and stress support alongside fasting.

Post-menopausal women may find they tolerate fasting more like men do, but individual response still matters.

One of my favourite resources for female fasting which I have shared with clients who also love it is this book available on Amazon: Fast Like a Girl: https://www.amazon.co.uk/Fast-Like-Girl-Healing-Hormones/dp/1401969925 helping to understand female hormones, nutrition and fasting safely around your cycle.

 

General Considerations Before Starting a Fast

Fasting can be powerful - but it’s not appropriate for everyone. It’s important to consider:

• Your current health: Those with blood sugar imbalances, eating disorders, thyroid issues, or who are pregnant, or breastfeeding should avoid fasting or only do so with professional support.

• Stress levels: Fasting is a form of physical stress. If you're already under chronic stress, fasting might be more harmful than helpful.

• Sleep: Poor sleep can make fasting harder and reduce its benefits.

• Activity level: If you’re highly active, you may need to modify fasting windows to support energy and recovery.

  
  

Fasting should feel empowering, not depleting. If you feel overly fatigued, irritable, dizzy, or have trouble concentrating, it may not be the right time for you. Also, as per the above, remember if you are female the impact of your hormones during your cycle and fasting.

General Nutritional Support for Fasting

What you eat before and after a fast can significantly impact how well you tolerate it and the benefits you experience.

Before a Fast

• Focus on nutrient density: Build meals around whole foods - think colourful vegetables, healthy fats, quality protein, and complex carbohydrates.

• Hydrate well: Dehydration can exacerbate symptoms like fatigue or headaches during fasting.

• Stabilise blood sugar: A balanced meal with protein, fat, and fibre can prevent a crash during the fast.

Example: A salad with grilled salmon, avocado, olive oil, and quinoa.

During a Fast

• Most fasting methods allow non-caloric beverages: water, herbal teas, black coffee (if tolerated).

• Stay hydrated with water and consider adding a pinch of sea salt or electrolytes if you feel dizzy or lightheaded.

  
  

Breaking a Fast

• Avoid going straight for heavy or sugary foods.

• Start with a gentle, nourishing meal: something easy to digest but still balanced. Think gentle fats like avocado and an easily digestible vegetable and chicken soup.

• Include protein to rebuild and support blood sugar and avoid a large spike in insulin.

OK, I am interested in fasting what do I do now?!

Well…. When I work with clients, I don’t have a one size approach as you can see from earlier on in this blog. This is why I find the questions about fasting on “the hop” so difficult. It isn't as simple as do x, y, z.

If you are stressed and low in energy for example, I may encourage to start with 3 balanced meals per day including breakfast. Opting straight for a fast could well put your already stressed body into a more stressed state. Building from a solid foundation makes it easier to move into into a fasting protocol but the foundations need to be solid.

Neither water nor juice fasting should be undertaken lightly. Preparation and re-introduction of food are just as important as the fast itself. For most people, especially women or those under stress, a modified fast or intermittent fasting may be more sustainable and supportive long-term.

If you're curious about trying a fast, I can help guide you through a plan that supports your health and fits your lifestyle. Reach out for a free 20 minute call to explore your goals.

Book a free discovery call

The content provided is not intended to treat, diagnose, cure or prevent any disease. All material on laurabealesnutrition.co.uk is provided for information and educational purposes only. Always seek the advice of your doctor and/ or another qualified healthcare provider for any questions you have regarding a medical condition, and before undertaking any diet, supplement, exercise or other health-related programs.