People who are insulin-sensitive only need a small amount of insulin to normalize the levels of glucose in the blood. However, those who are insulin-resistant usually require more insulin to help normalize glucose levels in their blood.

According to one study, healthy men who undergo nutritional cleansing four times a week for two weeks tend to develop an increase in their glucose uptake, resulting in an improved regulation of glucose levels in the blood and greater insulin sensitivity.

Although only conducted on animals, there are studies that show promising results on the effects of fasting on the brain. According to these studies, the production of brain-derived neurotrophic factor (BDNF) is stimulated by fasting. An increased production of BDNF also increases the ability of the brain's neurons to withstand degeneration as well as enhance memory and learning.

An increase in the levels of BDNF also leads to increased levels of serotonin, which confirms the improved moods of aging men after having a two-day nutritional cleanse.