Is intermittent fasting healthy?

A Chinese study presented at the American Heart Association’s Epidemiology, Prevention, Lifestyle and Cardiometabolic Health conference suggests that intermittent fasting may nearly double a person's long-term risk of dying from cardiovascular diseases such as heart attack and stroke. Intermittent fasting, or time-restricted eating, involves limiting food intake to specific number of hours each day. The 16:8 eating schedule is the most popular method where people eat all their meals in an eight-hour window and fast for the remaining 16 hours.

Various short-term research has linked intermittent fasting to weight loss and improved heart health markers, such as blood pressure, blood sugar and cholesterol levels. To analyse the long-term health impact of following an eight-hour time-restricted eating plan, researchers reviewed dietary data from a national survey of 20,078 Americans aged 49, on average.

During a median follow up of eight years, people who ate all their food in an eight-hour window had a 91 per cent higher risk of death from cardiovascular diseases compared with those who ate over a 12- to 16-hour time frame. This increased cardiovascular disease mortality was seen in the general population as well as in those who had pre-existing cardiovascular disease or cancer. An eating duration of less than 10 hours per day was also associated with a 66 per cent higher risk of cardiovascular death in people with heart disease.

Time-restricted eating did not reduce a person’s overall risk of death from any cause. But an eating duration of more than 16 hours per day was associated with a lower risk of dying among people with cancer. “It is crucial for patients, particularly those with existing heart conditions or cancer, to be aware of the association between an eight-hour eating window and increased risk of cardiovascular death,” the study cautioned.