Diet and physical activity Diet and physical activity are important health behaviors that affect the risk of both cancer and cardiovascular disease. Common health conditions such as overweight/obesity, cardiovascular disease, and osteopenia/osteoporosis may develop as a primary effect of specific cancer treatments or as a secondary effect of cancer on functional status, and dietary interventions offer the potential to reduce such cancer-related morbidity and promote overall health in vulnerable patients. Dietary interventions targeting patients with cancer have been evaluated in 11 prospective controlled trials that focused on either weight reduction (de Waard et al., 1993; Loprinzi et al., 1996; Djuric et al., 2002), fat restriction (Boyar et al., 1988; Chlebowski et al., 1992; Rose et al., 1993; Kristal et al., 1997), or specific nutrient intake (Nordevang et al., 1992; Pierce et al., 1997; Hebert et al., 2001; Pierce et al., 2004). Intervention methods have involved primarily resource-intensive, individualized counseling sessions delivered by trained nutritionists, although some studies have relied on trained volunteer staff (Kristal et al., 1997) or commercial weight loss programs such as Weight Watchers (Djuric et al., 2002). In addition to individualized instruction, some interventions have used such approaches as group sessions or telephone counseling (Pierce et al., 2004). Study results indicate that these interventions are largely effective in promoting dietary change as determined by dietary intake (Chlebowski et al., 1992; Nordevang et al., 1992; Pierce et al., 1997, 2004; Hebert et al., 2001), body weight (Boyar et al., 1988; Chlebowski et al., 1992; de Waard et al., 1993; Rose et al., 1993; Loprinzi et al., 1996; Kristal et al., 1997; Hebert et al., 2001; Djuric et al., 2002), and hormonal status (Boyar et al., 1988; Rose et al., 1993). Notably, some studies were limited by high attrition rates, which in most cases were similar among treatment and control participants (Chlebowski et al., 1992; Kristal et al., 1997; Pierce et al., 1997; Djuric et al., 2002). Moreover, evidence supporting the sustainability of the positive impact of interventions beyond 1 year is limited (Chlebowski et al., 1992). Several ongoing multisite trials are aimed at evaluating maintenance of the effects of dietary interventions and the relationship to survival outcomes. Preliminary results of the Women’s Intervention Nutrition Study demonstrate significant reductions in dietary fat and weight in 290 women randomized to individual dietary instruction versus controls (Chlebowski et al., 1992). Investigators coordinating the Women’s Healthy Eating and Living Study Intervention Nutrition Study similarly observed significant increases in intake of vegetables, fruits, and fiber that was confirmed by nutrient biomarkers among patients with breast cancer randomized to receive individualized dietary telephone counseling (Pierce et al., 2004). Continued follow-up of these groups will provide important information about the impact of dietary interventions on cancer-free survival.

The benefits of regular physical activity include improvements in