The Seattle Times notes recent research: "A new study finds that calorie restriction may bolster the immune system in adults. Researchers [randomly] placed 46 overweight, but not obese, men and women age 20 to 40 on one of two diets for six months: one in which calories were reduced 10 percent, and another in which they were reduced 30 percent. All food was supplied to the test subjects. The participants were tested to see what effect calorie restriction had on their immune system. They were given a delayed-type hypersensitivity test, which can detect allergens, among other things, and is considered a way to check whole-body immune response. Researchers also checked T-cells, a kind of white blood cell, and another immune system marker. At the end of the six months, [delayed type hypersensitivity] response went up in both the 10 percent and the 30 percent calorie-restricted groups compared with the beginning of the study. Both groups also showed improvement in T-cell function."