Telephone counseling promotes dietary change in healthy adults: results of a pilot trial

Telephone counseling is increasingly reported to be an effective behavior change strategy, but more studies in broader populations are needed. This uncontrolled pilot trial investigated whether a 3-month/eight-call telephone counseling intervention could promote dietary changes associated with reduced chronic disease risk in adults consuming <5.0 servings of vegetables and fruits daily. Between 2002 and 2004, 97 adults (mean age 46 years; range 21 to 84 years) completed the intervention and a follow-up assessment at 6 months. Approximately half were of nonwhite ethnicity (53%). The majority were women (95%) and had never had cancer (89%). The intervention promoted daily intakes of three to five vegetable servings, two to four fruit servings, and three whole-grain and/or beans/legumes servings. Average total daily intake of vegetables, fruits, whole grains, beans/legumes, fiber, and fat were assessed at baseline and at 6 months, each by a set of three 24-hour recalls. Plasma carotenoids were measured on a subsample (n=41) as an objective biomarker of vegetable and fruit intake. Change in mean self-reported dietary intake (ie, vegetables, fruit, whole grains, beans/legumes, fiber, and fat) and plasma carotenoids were compared by paired t tests. The intervention was associated with a significant (P<0.001) increase in vegetable servings per day (baseline 2.1 servings per day, 6 months 3.5 servings per day; 67% increase), fruit servings per day (baseline 1.4 servings per day, 6 months 2.4 servings per day; 71% increase), and whole-grain and/or bean servings per day (baseline 1.0 serving per day, 6 months 1.4 servings per day; 40% increase). These changes were corroborated by a significant (P<0.001) increase in total plasma carotenoids. This 3-month/eight-call telephone counseling intervention was associated with dietary change in healthy adults consuming fewer than five servings per day of vegetables and fruit at study entry.