Intermittent Fasting: A Dietitians Perspective on the Pros & Cons
By Annaliese Collier from Your (Gut) Feeling
Over the past few years, intermittent fasting has gained significant popularity as a method for weight loss and improving overall health. In this blog post, we will explore the pros and cons of intermittent fasting - from a dietitian's perspective. As with all big decisions, such as making significant changes to your diet and lifestyle, it is essential to consider both the benefits and drawbacks.
Intermittent fasting refers to eating patterns that alternate between periods of fasting (no food or drink containing energy) and eating. The fasting period can vary from 12 hours per day to several consecutive days, following a consistent pattern throughout the week.
There are several main types of intermittent fasting:
1. Alternate day fasting: This involves alternating between fasting days and days where food and beverages are consumed typically without restriction.
2. Modified fasting or the 5:2 diet: This protocol includes fasting for two non-consecutive days of the week and eating normally for the remaining five days.
3. Time-restricted eating: This type of fasting limits the "eating window" to 4-12 hours, including a daily fasting period of 12-20 hours. During the eating window, individuals can eat to satiety without calorie restriction.
Among these types, time-restricted eating, specifically the 16:8 pattern (eating during an 8-hour window and fasting for 16 hours each day), is the most popular and widely recommended.
The pros of intermittent fasting:
1. Simplicity: One of the advantages of intermittent fasting is its simplicity. Unlike strict calorie counting or meal plans, intermittent fasting can offer a straightforward approach. It involves dividing your day or week into eating and fasting periods. This flexibility can allow you to choose a fasting schedule that fits your lifestyle.
2. Potential Weight Loss: Intermittent fasting can be an effective strategy for weight loss. By restricting the eating window, you naturally reduce your overall calorie intake, which may lead to a calorie deficit and subsequent weight loss. However, compared to standard caloric restriction, intermittent fasting did not provide an advantage in promoting weight loss.
3. Health Benefits: Research suggests intermittent fasting may offer various health benefits beyond weight loss. It has been associated with improved blood sugar control, reduced inflammation, enhanced heart health, and potential longevity benefits. However, further studies are needed to understand the long-term health effects fully.
The cons of intermittent fasting:
1. Potential Nutrient Deficiencies: Depending on the fasting schedule and food choices during eating periods, intermittent fasting may increase the risk of nutrient deficiencies. With shorter eating windows, meeting your daily nutrient requirements can be challenging. It is crucial to ensure that your meals during the eating periods are well-balanced and nutrient-dense to prevent deficiencies.
2. Disrupted Eating Patterns: Intermittent fasting may disrupt regular eating patterns, which can be challenging for some individuals. Skipping meals or prolonged fasting may lead to excessive hunger, irritability, and difficulty concentrating. It may not be suitable for those with certain medical conditions, such as diabetes, active growth stage (e.g., adolescents), pregnancy or breastfeeding, or a history of disordered eating.
3. Adherence Challenges: Intermittent fasting may only be sustainable or suitable for some. It requires discipline, has a rigid structure, and necessitates eating within specific windows, which can impact your quality of life and relationships. Listening to your body and considering your needs and preferences is essential before starting an intermittent fasting regimen.
4. Potential Negative Relationship with Food: For some individuals, intermittent fasting may trigger an unhealthy relationship with food. It can lead to obsessive thoughts about eating and a tendency to overeat or binge during eating periods. Strict and rigid food rules or diets are often impossible to stick to, especially during stressful times. The rigid rules around the timing of eating may become overwhelming on certain days and be broken, leading to feelings of guilt or low self-worth. It's important to note that dieting has been identified as one of the most significant risk factors for developing and maintaining an eating disorder.
In summary, intermittent fasting can be a simple method for weight loss and improving specific health markers. However, it is no more advantageous than following a healthy balanced diet or engaging in standard caloric restriction for weight loss. It is also essential to consider the potential drawbacks, including nutrient deficiencies, disrupted eating patterns, adherence challenges, and the potential for a negative relationship with food.
As with any dietary approach, consulting with a qualified healthcare professional or registered dietitian is essential before starting intermittent fasting. They can help tailor the approach to your individual needs, guide proper nutrition, and monitor your overall health and well-being.
To learn more about diet and nutrition, head to Annaliese’s website Your (Gut) Feeling