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Intermittent fasting: benefits or risks? Study raises questions about heart health

August 31, 2025

Intermittent fasting, which restricts eating to specific time windows, has gained popularity as a diet trend embraced by celebrities and tech executives. While previous short-term research suggested benefits like improved metabolism and cellular repair, a new large-scale study analyzing data from over 19,000 adults raises serious concerns. The research found that people who limited their eating to less than eight hours daily faced a 135% higher risk of dying from cardiovascular disease compared to those who ate over 12-14 hours.

Who is affected

  • People practicing intermittent fasting with eating windows under eight hours
  • Individuals with diabetes or existing heart disease (at highest risk)
  • Smokers (who showed stronger negative associations)
  • Older adults or those with chronic conditions (may experience worsened frailty or muscle loss)
  • People across various socioeconomic groups (as the risk was consistent across these demographics)

What action is being taken

  • Researchers are analyzing data from more than 19,000 adults to study the relationship between time-restricted eating and health outcomes
  • Scientists are tracking eating habits through dietary recalls to estimate average eating windows
  • Medical experts are investigating the contradictions between short-term studies showing benefits and long-term data showing risks
  • Researchers are examining the link between restricted eating windows and cardiovascular mortality across different population groups
  • Nutritionists and endocrinologists are weighing the promise and pitfalls of intermittent fasting

Why it matters

  • The findings challenge the popular belief that time-restricted eating improves heart and metabolic health
  • The study reveals a potentially serious health risk (135% higher cardiovascular mortality) associated with a widely practiced diet trend
  • The research suggests different health outcomes between short-term and long-term intermittent fasting
  • It indicates that dietary recommendations may need to be personalized based on individual health status
  • The study highlights that what people eat may be more important than when they eat for cardiovascular health and longevity

What's next

  • No explicit next steps stated in the article

Read full article from source: BBC

Intermittent fasting: benefits or risks? Study raises questions about heart health