Intermittent Fasting May Not Be the Right Choice for You

Intermittent fasting has surged in popularity in the last few years. Many will say that they fast for more energy and improved focus, but most will use fasting as a go-to strategy for weight loss.

While some people swear by it (and it works well for them), intermittent fasting isn’t a one-size-fits-all solution. For certain people, it may bring unintended side effects such as weight gain, increased stress, or worsening of existing health issues - the opposite of what they're looking for!

Today, I explore who may benefit from intermittent fasting, who should exercise caution with it, and why professional guidance is crucial before starting this eating pattern.

What is Intermittent Fasting?

Intermittent fasting is a little about what you eat, but it's mostly about when you eat. The most common approaches include:

• The 16/8 method: Fasting for 16 hours and eating during an 8-hour window. There are other time variations on this too.

• The 5:2 method: Eating normally for five days and reducing calorie intake significantly for two non-consecutive days.

• Eat-stop-eat: Involves a 24-hour fast once or twice a week.

Although many followers rave about its simplicity and potential benefits, intermittent fasting may not be as effective or suitable for everyone. Unfortunately in clinic, I see mostly the 'not working' type. I have a few ideas why this might be happening, but we certainly have to handle it on a case-by-case basis.

The Downsides of Intermittent Fasting

1. Unexpected Weight Gain: Many people turn to intermittent fasting with the goal of weight loss, expecting the restricted eating windows to help them consume fewer kilojoules overall. However, this isn't always the case.

   Fasting can lead to excessive hunger, prompting overeating during eating windows. Some people may also experience cravings for high-calorie, nutrient-poor foods after fasting, which could counteract any calorie deficit they hoped to achieve. Think of it this way; you've starved the body for longer than expected, so naturally your body looks for high-kilojoule options to restore reserves as quickly as possible.

   Weight gain can also come from compensatory eating, where people feel they need to make up for the hours they’ve fasted (often sub-consiously). Instead of reducing caloric intake, they might end up consuming more food, especially if they’re fatigued or emotionally stressed. This can lead to weight gain, leaving individuals feeling discouraged when their primary goal was to shed kilos.

   
   

2. Heightened Stress Levels: Fasting itself can be a stressor for the body. While mild stress can trigger beneficial adaptive responses, like improved cellular repair and fat metabolism, prolonged or poorly timed fasting can tip the scales into chronic stress. This, in turn, can increase levels of cortisol, the stress hormone, which may lead to fat retention, particularly around the abdomen.

   Increased cortisol levels can also contribute to mood swings, poor sleep, and fatigue. For people already dealing with stress from their lifestyle, work, or personal life, adding fasting to the mix may amplify their stress levels, negatively impacting both their mental and physical health. Cortisol can increase weight gain (think: work, life, money) then you add fasting and it can fuel the stress-fire, so to speak.

   
   

3. Blood Sugar and Energy Issues: Fasting can sometimes lead to unstable blood sugar levels, especially in people with sensitive metabolisms. Skipping meals, particularly breakfast, may cause significant dips in blood sugar, which can leave you feeling dizzy, weak, and irritable. If you’ve ever experienced a “hangry” episode, you know how disruptive this can be.

   For those with diabetes or blood sugar regulation issues, intermittent fasting could be dangerous if not properly managed. Dramatic changes in blood sugar can also lead to fatigue, making it harder to stay focused or energised throughout the day.

   
   

4. Risk of Disordered Eating Patterns: Intermittent fasting can foster a disordered relationship with food in some individuals. The emphasis on restricting eating times can create anxiety around food, especially if someone is prone to restrictive eating patterns or has a history of eating disorders. The pressure to “eat enough” during a short window can lead to binge eating behaviours, while the anxiety of fasting can make food feel like an enemy.

   Those with a past of disordered eating or body dysmorphia should be particularly cautious with intermittent fasting, as it may exacerbate unhealthy patterns.

   
   

5. Hormonal Imbalances, Especially for Women: For some women, intermittent fasting can disrupt hormones, particularly if combined with stress or a restrictive diet. Prolonged fasting periods may lead to irregular menstrual cycles, fertility issues, and disrupted oestrogen and progesterone levels. Women’s bodies are sensitive to energy balance, and chronic under-eating, which can occur during fasting, may affect hormone production.

   Moreover, fasting can affect the thyroid gland, potentially slowing down metabolism if your body senses it’s not receiving enough consistent energy. This could ultimately contribute to weight gain or difficulties losing weight.

   
   

While some people thrive on intermittent fasting, it’s not recommended for certain groups, including:

• Pregnant or breastfeeding women: The energy demands are higher during these times, and fasting can affect both mother and child’s health.

• People with a history of eating disorders: Fasting may trigger unhealthy eating behaviours.

• Individuals with certain medical conditions: People with diabetes, low blood pressure, or metabolic issues should be cautious and consult their healthcare provider before trying fasting.

• Athletes or those with intense physical demands: Fasting may reduce available energy, leading to poor performance or recovery in athletes.

Who Can Benefit from Intermittent Fasting?

Intermittent fasting may work well for certain individuals, particularly those who have a stable relationship with food and a balanced lifestyle. Some data suggests that fasting may be beneficial for older people, who may not need the higher levels of kilojoules they used to. This would be people in the 50+ category (when women have entered menopause, and therefore have less concerns about hormone disruption).

There are some studied benefits to fasting, which you've probably read about. They include:

1. Improved Insulin Sensitivity: For some individuals, intermittent fasting may improve insulin sensitivity, particularly in those at risk of type 2 diabetes or with mild insulin resistance. When the body has longer periods without food, it may improve how it processes and uses glucose.

   
   

2. Weight Loss for Overweight Individuals: Some studies suggest intermittent fasting can lead to weight loss, especially in people with obesity. The extended fasting period can create a calorie-deficit, potentially leading to fat loss, if not compensated with overeating during eating windows.

   
   

3. Increased Cellular Repair: Fasting may encourage autophagy, a process where cells remove damaged components and recycle them. This could support healthy ageing and reduce the risk of chronic diseases.

   
   

4. Improved Mental Clarity: Some people report feeling more focused and mentally clear during fasting, especially after the initial adjustment period. This could be due to stable blood sugar levels and the reduced digestive burden.

The Importance of Consulting a Nutrition Professional

Fasting is no joke! I don't recommend 'giving it a go' without proper preparation. Success from fasting takes careful consideration, planning, preparation, and a period of time for the body to adjust to it. In all honesty, most people have it all wrong, hoping for fast weight loss, corrected blood sugar and surges in energy and focus. Fasting can be great, but at it's core, it is a way of eating which brings with it strong rules around food consumption. In my practice and experience, I find this often moves people away from feeling safe and nourished from food and mentally healing from disordered eating.

While intermittent fasting might appeal to those seeking health outcomes, it is essential to remember that fasting affects everyone differently. A nutrition professional can provide personalised guidance on whether fasting is suitable for you, considering factors such as your medical history, lifestyle, and specific health goals. A health professional will monitor your progress, ensuring the approach is sustainable and safe for your long-term health.

Intermittent fasting may have its place in the toolbox of healthy eating patterns, but it’s not for everyone. For some, it could cause more harm than good, leading to unexpected weight gain, increased stress, or other health issues. Before diving into any fasting regimen, it’s crucial to consult with a nutrition professional who can guide you through the process, ensuring it aligns with your individual needs and health status. Always prioritise your well-being over trends, and make informed decisions when it comes to your health!