In order to study the relationship between light fasting and human health, an institution recruited a group of volunteers for the experiment. The volunteers were divided into two groups. The experimental period was 6 months. The recommended amount of diet was the same standard. The first group of volunteers cut off food continuously for 5 days every month. On the first day, the calorie intake was reduced to half of the recommended amount. After 4 days, the daily amount was only one third of the recommended amount. The second group of volunteers, during the test period, the volunteers ate normally every day. The test results showed that the physical condition of the first group of volunteers had been significantly improved. 
the researchers concluded that light fasting made the volunteers produce more ketones, and the water, a marker of oxidative stress and inflammation, decreased on average.
The physical function and stress response of the recruited volunteers are different.