Intermittent Fasting: A Closer Look at Heart Health Risks

Thu Oct 23 2025 03:49:16 GMT+0300 (Eastern European Summer Time)

Recent research raises significant concerns about the health effects of intermittent fasting, particularly regarding cardiovascular disease. This study challenges the common perception of fasting as a healthful practice.

Intermittent fasting, touted as a revolutionary approach to dieting, may carry serious health risks according to new research. An extensive study involving over 19,000 adults indicates that limiting eating to less than eight hours daily can lead to a significantly higher risk of dying from cardiovascular disease. While intermittent fasting is often linked to weight loss and metabolic benefits, experts urge caution, particularly for individuals with pre-existing health conditions. The emphasis is shifting towards personalized dietary recommendations over strict timing of meals.

Intermittent Fasting: A Closer Look at Heart Health Risks

Intermittent fasting has become the diet trend of the decade, promising to hack biology without the drudgery of counting calories or cutting carbs. Tech moguls and Hollywood stars swear by it, while Britain's former prime minister, Rishi Sunak, even highlighted his own use of a 36-hour fast as part of his routine.

Initial scientific support for intermittent fasting suggested benefits such as improved metabolism, cellular repair, and potential life extension. However, nutritionists have consistently warned that there are no shortcuts to health, especially for individuals with underlying conditions.

The practice compresses eating into a limited timeframe—often eight hours—resulting in a 16-hour fasting period. Contrasting diets, like the 5:2 diet, alternate calorie restriction rather than time restriction.

New findings from a large-scale study involving over 19,000 adults put these assumptions to the test, revealing a stark warning: those who confined their eating to less than eight hours experienced a staggering 135% increase in mortality risk from cardiovascular disease compared to individuals who maintained a 12-14 hour eating window.

This heightened risk applies across various demographic factors and was particularly pronounced among smokers and those with diabetes or existing heart conditions, implying they should exercise caution with narrow eating windows.

While the association with overall mortality was less pronounced, the persistent cardiovascular risk raises significant concerns about fasting as a path to health. Researchers emphasized that the findings do not establish a causative relationship but pose serious questions about the benefits of intermittent fasting.

Experts like Victor Wenze Zhong, the lead author of the study, suggest that the focus should shift from when one eats to what one eats, advocating personalized dietary advice based on individual health status and evolving evidence. Until clearer evidence is found, the messages indicate a need for caution rather than a blanket endorsement of intermittent fasting.

This study draws attention to previously raised concerns regarding nutritional deficiencies, increased cholesterol, and adverse behavioral effects associated with fasting. It highlights the necessity of individualized dietary strategies, especially for individuals with pre-existing health concerns, suggesting that adopting an eight-hour eating window might not be advisable for long-term health.

In conclusion, while intermittent fasting may support weight loss and metabolic health in some, careful consideration of its implications for cardiovascular health is paramount, especially among vulnerable populations. The best approach may well focus on balanced nutrition rather than strict fasting windows.