A major new scientific review has delivered a significant blow to the popular dieting trend of intermittent fasting, concluding that the evidence "doesn't justify the enthusiasm" surrounding it for weight loss.
Study Finds Little to No Advantage
The comprehensive Cochrane review, led by researchers in Argentina, meticulously examined 22 separate trials involving 1,995 adults across North America, Europe, China, Australia, and South America. The analysis compared various forms of intermittent fasting—including alternate-day fasting, periodic fasting, and time-restricted eating—with traditional dietary advice.
The authors concluded that "intermittent fasting may result in little to no difference in weight loss, measured as change from starting weight." This finding directly challenges the widespread perception of the technique as a superior weight management tool.
Lead Researcher's Assessment
"Intermittent fasting just doesn't seem to work for overweight or obese adults trying to lose weight," stated Luis Garegnani, lead author of the review from the Universidad Hospital Italiano de Buenos Aires Cochrane Associate Centre.
Garegnani elaborated, "Intermittent fasting may be a reasonable option for some people, but the current evidence doesn't justify the enthusiasm we see on social media. Obesity is a chronic condition. Short-term trials make it difficult to guide long-term decision-making for patients and clinicians."
Understanding Intermittent Fasting Methods
The dieting technique, which has gained immense popularity and celebrity endorsement in recent years, involves several distinct approaches:
- Alternate-day fasting: A 24-hour fast on every second day.
- Time-restricted eating: Consuming food only during a specific window, such as the 16:8 diet (16 hours fasting, 8 hours eating).
- Whole-day fasting: Includes methods like the 5:2 diet, involving five normal eating days and two fasting days.
Despite its varied applications, the new research suggests these methods do not confer a measurable weight loss advantage over conventional calorie-restricted diets.
Clinical Implications and Recommendations
Eva Madrid, senior author of the paper from Cochrane Evidence Synthesis Unit Iberoamerica, emphasized the need for individualized medical advice. "With the current evidence available, it's hard to make a general recommendation," she said. "Doctors will need to take a case-by-case approach when advising an overweight adult on losing weight."
The Broader Context of Obesity in England
This research arrives amid concerning public health statistics. The Health Survey for England, published in January, revealed that 30% of adults are obese, while a staggering 66% are either overweight or living with obesity.
Furthermore, figures released by NHS Digital indicate that more than a quarter (27%) of adults in England are classified as inactive, meaning they engage in less than 30 minutes of moderate or vigorous activity per week. Additionally, 48% of adults were found to have raised cholesterol levels.
The study underscores the complexity of weight management and suggests that sustainable, long-term strategies, rather than trending short-term dietary fads, may be more critical in addressing the obesity epidemic.
