The Veracity of Water Fasts: Can the Advantages Truly Endure?
A recent study conducted by the University of Illinois Chicago sheds light on the effects of water fasting, a practice where individuals consume only water for a period of time. While water fasting does lead to short-term weight loss, the study reveals that its metabolic benefits, such as improved blood pressure and cholesterol levels, tend to diminish shortly after the fast concludes.
The research, which was led by Krista Varady, a professor of kinesiology and nutrition, suggests that there are no significant adverse effects associated with water fasting or similar low-calorie intake regimens. The study, published in the journal Nutrition Reviews, underscores the need for caution and medical supervision if one chooses to undertake a fast lasting longer than five days.
Varady, an expert in intermittent fasting, was prompted to investigate water fasting due to growing interest from journalists. She believed it was essential to delve into existing research before providing insights into this fasting practice.
The study itself comprises a literature review of eight studies on water fasting, including Buchinger fasting, a medically supervised fasting method popular in Europe, where individuals consume minimal amounts of juice and soup each day. Varady’s team analyzed the cumulative results from these studies to evaluate the impact of fasting on weight loss and various metabolic factors.
The findings indicate that water fasting does indeed lead to noticeable short-term weight loss. Participants who fasted for different durations experienced varying degrees of weight loss, with those fasting for five days losing around 4% to 6% of their weight, and longer fasts of 15 to 20 days resulting in 7% to 10% weight loss.
However, the study found limited information on whether participants regained the lost weight after the fasts ended. Some studies suggested weight regain, but others encouraged calorie restriction after fasting, potentially influencing the outcomes.
What stands out most prominently is that the metabolic benefits of fasting, such as improvements in blood pressure, cholesterol, and blood sugar levels, were short-lived. These improvements quickly reverted to baseline levels once participants resumed their regular diets.
Notably, the study included participants with Type 1 and Type 2 diabetes, who experienced no adverse effects from fasting, provided they were closely monitored, and their insulin doses were adjusted as needed during the fasts.
The common side effects of extended fasting were similar to those associated with intermittent fasting, including headaches, insomnia, and hunger. Fortunately, no serious negative effects, such as metabolic acidosis or mortality, were observed.
It’s worth mentioning that participants in prolonged fasts predominantly lost lean mass (approximately two-thirds) rather than fat mass (one-third), contrary to typical weight loss patterns where fat loss predominates. This outcome is attributed to the body’s need for a consistent protein intake; without it, the body resorts to breaking down muscle tissue.
In conclusion, while water fasting may yield short-term weight loss, its sustainability and long-term benefits remain uncertain. Those seeking weight management solutions might find intermittent fasting, with a more extensive body of supporting evidence, a more viable option.
Reference: “Efficacy and safety of prolonged water fasting: a narrative review of human trials” by Mark Ezpeleta, Sofia Cienfuegos, Shuhao Lin, Vasiliki Pavlou, Kelsey Gabel and Krista A Varady, 27 June 2023, Nutrition Reviews.
DOI: 10.1093/nutrit/nuad081
Additional contributors to the study from the University of Illinois Chicago include Sofia Cienfuegos, Shuhao Lin, Vasiliki Pavlou, and Kelsey Gabel, as well as Mark Ezpeleta, a former UIC student.
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Frequently Asked Questions (FAQs) about Water Fasting Benefits
Q: What is water fasting, and does it lead to weight loss?
A: Water fasting involves consuming only water for a specified period. Yes, it often results in short-term weight loss, with varying degrees based on the duration of the fast.
Q: Are there lasting metabolic benefits associated with water fasting?
A: Unfortunately, the study suggests that metabolic advantages, such as improved blood pressure and cholesterol levels, tend to diminish once the fasting period concludes.
Q: Is water fasting safe?
A: According to the research led by Krista Varady, there are no notable negative side effects associated with water fasting, but it’s essential to exercise caution and seek medical supervision for fasts lasting more than five days.
Q: What were the common side effects of prolonged fasting?
A: Common side effects included headaches, insomnia, and hunger, similar to those observed with intermittent fasting. However, serious negative effects were not reported.
Q: Did participants regain the weight lost during water fasting?
A: Some studies suggested weight regain, while others encouraged calorie restriction after fasting, potentially influencing the outcomes. Further research is needed to establish long-term weight maintenance after water fasting.
3 comments
fasting might help drop pounds but quick benefits don’t last, not sure it’s worth it. safer ways like intermittent fasting for weight!
interesting findings! Water fasting seems tricky, better options for weight loss. need more research on long-term effects.
so, study say water fasting = lose weight short-term but benefits like blood pressure + cholesterol vanish? need to b careful with long fasts!