Growing evidence suggests dietary restriction helps our body fight cancer. A new study helps explain how cutting calories while maintaining good nutrition may improve immune and metabolic function and delay the onset of certain age-related diseases. The study, published in the journal Nature Metabolism, explores a low-fat, high-protein diet with one-third to one-half fewer calories than normal. The result helped T-cells of the immune system to be more effective tumor fighters. Authors at the Van Andel Institute note calorie restriction can be a complex issue, since people with cancer already face significant challenges in meeting their nutritional needs because of loss of appetite, hence the need for nutritional programs tailored to individuals.