Fasting may increase metabolism and help preserve muscle tissue to reduce body weight and body fat.

Intermittent fasting and alternate-day fasting could help decrease blood sugar levels and reduce insulin resistance but may affect men and women differently.

Studies show that fasting can increase levels of human growth hormone (HGH), an important protein hormone that plays a role in growth, metabolism, weight loss and muscle strength.

Some animal and test-tube studies suggest that fasting could block tumor development and increase the effectiveness of chemotherapy.

Animal studies have found that fasting could delay aging and increase longevity, but human research is still lacking.

Some studies have found that fasting could decrease several markers of inflammation and may be useful in treating inflammatory conditions, such as multiple sclerosis.

Animal studies show that fasting could improve brain function, increase nerve cell synthesis and protect against neurodegenerative conditions, such as Alzheimer’s disease and Parkinson’s.