This trial studies how well a nutrition and physical activity intervention works in preventing excess weight gain in pediatric patients with leukemia or lymphoma treated with Treated with prednisone and/or dexamethasone. A nutrition and physical activity intervention may help develop healthier eating habits and prevent rapid excess weight gain in pediatric patients with leukemia or lymphoma who are receiving prednisone and/or dexamethasone.

PRIMARY OBJECTIVES:

I. To evaluate if a nutrition counseling intervention will prevent an increase in waist circumference from baseline measurements for children/adolescents diagnosed with leukemia or lymphoma and being treated with prednisone and/or dexamethasone.

SECONDARY OBJECTIVES:

I. To conduct qualitative research on diet habits, likeability of low-fat and-low sucrose foods.

II. To conduct qualitative research on exercise habits and willingness to engage in moderate walking.

III. To assess receptivity to electronic dietary and physical activity (PA) interventions in pediatric cancer patients and survivors (PCPSs) and their parents.

IV. To determine if nutrition interventions will prevent an increase in body mass index (BMI) from baseline measurements for children/adolescents diagnosed with leukemia or lymphoma and being treated with prednisone and/or dexamethasone.

V. To determine if a nutrition counseling intervention will help maintain or decrease triglyceride and cholesterol levels, prevent abnormal values of hemoglobin A1C and improve absolute lymphocyte counts (ALC) from baseline measurements for pediatric leukemia or lymphoma patients, receiving prednisone and/or dexamethasone therapy.

VI. To evaluate caloric intake, nutritional parameters and oxidative stress in pediatric leukemia or lymphoma patients receiving prednisone and/or dexamethasone therapy.

VII. To evaluate responses to various energy balance interventions.

OUTLINE: Patients are randomized to 1 of 2 arms.

ARM I: Patients attend 13 nutrition counseling sessions over 45 minutes each for 1 year. Patients may receive nutrition handouts.

ARM II: Patients attend 2 tasting sessions for low-fat and low-sugar recipes and complete 2 PA sessions over 1 hour for each session.

Inclusion Criteria:

• Leukemia or lymphoma patient at MD Anderson Children's Cancer Hospital
• Patients receiving prednisone and/or dexamethasone therapy at MD Anderson Children's Cancer Hospital at time of enrollment
• Karnofsky performance status greater than or equal to 70
• Must be cleared by treating oncologist to participate in study
• Must live close enough to attend measurement sessions at one of the clinical centers

Exclusion Criteria:

• Patients receiving nutrition counseling or weight management counseling elsewhere
• Pediatric patients who are already receiving steroids that are not part of treatment
• History of psychological disorders as indicated in the medical record (eg: eating disorders, depression)