Water Fasting Safety and Suitability

Water Fasting Safety and Suitability

The Truth About Water Fasting: Is It Worth the Hype?

Water fasting has taken the world by storm, becoming the latest weight-loss sensation praised by former athletes and wellness gurus. However, according to a recent review of scientific evidence, the benefits of this trendy diet can quickly fade, and weight lost during the fast is often regained just as swiftly 1.

“I personally wouldn’t really recommend this diet,” warns Krista Varady, a professor of nutrition at the University of Illinois at Chicago and senior researcher of the review. “Even if people maintain the weight loss, all the health benefits go away.” So, before you jump on the water fasting bandwagon, let’s take a closer look at the facts.

What is Water Fasting?

Water fasting is a diet that involves consuming only water for a specific period, ranging from five to 20 days or even longer 2. Some supervised water fasts allow a small number of calories, such as 250 per day, typically in the form of juice or a small amount of soup 3. While there have been inspirational stories of successful water fasts, like former NFL player Russell Okung losing over 100 pounds in 40 days, it’s essential to examine the scientific evidence behind this practice 4.

The Reality of Water Fasting

When reviewing the available studies on water fasting, researchers found that significant short-term weight loss does occur. For instance, a five-day water fast can lead to a loss of about 4% to 6% of body weight, while fasting for 15 to 20 days can result in a 7% to 10% reduction 5. However, the concern arises when considering the composition of weight loss. Two studies found that participants tend to lose more lean muscle mass than fat mass during a water fast 6.

Researchers highlight the implications of this finding, explaining that reductions in lean mass can lead to a lower resting metabolic rate and ultimately put individuals at a higher risk of future weight regain 7. In one study, participants regained all the weight lost during a five-day water fast within just three months 8. Although maintaining a healthier diet and changing eating habits after fasting showed some potential to sustain weight loss, the evidence remains limited in this regard 9.

Short-Lived Health Benefits

While water fasting triggers short-term improvements in health markers such as blood pressure, cholesterol, and blood sugars, these benefits vanish soon after reintroducing food, regardless of weight fluctuations 10. The review emphasizes that even if individuals don’t regain the weight lost during fasting, they lose all the metabolic protective effects gained from the temporary improvements 11. Additionally, the control of blood sugar levels did not show significant improvements for patients with type 1 or type 2 diabetes who practiced water fasting 12.

Safety and Sustainability

Although water fasting appears relatively safe, with hunger, headaches, nausea, vomiting, and insomnia being the most common side effects, concerns about potential deficiencies in vitamins and minerals arise 13. Studies included in the review did not specifically assess nutrition deficiencies resulting from water fasting 14. However, experts suggest that sustainable alternatives like intermittent fasting are more suitable for long-term weight management and improved health outcomes 15.

Dr. Ivania Rizo, director of obesity medicine at the Boston Medical Center, states that short-term, extreme measures like water fasting are not sustainable solutions for chronic diseases such as obesity 16. Instead, she encourages exploring new weight-loss drugs like Ozempic, which reduce hunger and help individuals focus their energies on other aspects of life 17. By comparison, water fasting can become all-consuming, leaving individuals constantly preoccupied with thoughts of food 18.

The Takeaway

While the idea of losing weight quickly and experiencing health benefits may seem appealing, the reality of water fasting is not as vibrant or sustainable as portrayed by some success stories. The available scientific evidence indicates that any weight lost during a water fast is likely to be regained, and the health benefits obtained are short-lived 19. Furthermore, the potential risks and limitations of water fasting, along with its impact on mental and social well-being, raise concerns about its overall feasibility 20.

Opting for more sustainable approaches, such as intermittent fasting, within a specific time window, has shown encouraging results for weight management and overall health improvement 21. So, if you’re thinking about water fasting, consider the potential drawbacks and explore alternative methods that offer a more balanced and realistic approach to achieving your health and wellness goals.


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