For people of a normal weight, fasting for long periods can cause health complications, including increased strain on the heart, even with nutritional supplementation.

Therefore, fasts of this length should not be attempted by anybody. They are from a time in the 1960s where long-term fasts were being studied with frequency, but there are other studies from this time where patients experienced heart failure and in some cases died of starvation.

However, people with and without diabetes can experience benefits from fasting. Intermittent fasting, in particular, has shown to help the body repair damage without entering starvation, enabling an array of benefits, namely weight loss and reduced insulin resistance. Last year, American scientists revealed that short-term fasting also has health benefits for the heart.