This clinical trial studies whether the High Fiber Program can be used to increase fiber intake in patients undergoing allogeneic hematopoietic cell transplant (HCT). Allogeneic HCT is a procedure in which a person receives blood-forming stem cells (cells from which all blood cells develop) from a genetically similar, but not identical, donor. This is often a sister or brother, but could be an unrelated donor. It is a potentially curative therapy for many conditions that affect the blood and blood-forming organs, but many patients must manage post-transplant complications, especially graft versus host disease (GVHD). GVHD occurs when the transplanted cells from a donor attack the body's normal cells causing skin rash or blisters, dry mouth, or dry eyes. The environment and health of the gut is important in allogeneic HCT patients, with an unhealthy gut environment and/or health leading to inflammation and possibly GVHD. Research has shown that diets high in fiber may improve the environment and health of the gut as well as outcomes following transplant; however, fiber intake remains low among patients. The High Fiber Program is a dietitian-led counseling program which teaches patients how to introduce high fiber foods into their diet and identify food choices and personalized strategies that will help them change their diet. The High Fiber Program may be an effective way to increase fiber intake in patients undergoing allogeneic HCT.