JMIR Publications

ABSTRACT

Background:

Randomized controlled trials conducted in Mediterranean countries have shown that the Mediterranean diet lowers adverse cardiovascular events. In the American population, diet remains the biggest uncontrolled risk factor for cardiovascular disease, and patients with cardiovascular disease require more extensive dietary counseling to reduce their risk of myocardial infarction, stroke and hypertension.

Objective:

Our study tested the hypothesis that asynchronous dietary counseling supplied through a custom smartphone application results in better adherence to a Mediterranean diet in a non-Mediterranean population compared with traditional standard-of-care counseling.

Methods:

100 patients presenting to the cardiology clinic of an academic medical center in Washington D.C. were randomized to either the standard-of-care (SOC) or smartphone app-based (EXP) Mediterranean diet intervention after informed consent and 1 hour of individual face-to-face dietary counseling with a registered dietician. Participants in EXP received a custom smartphone application that reinforced the Mediterranean diet while participants in SOC received two additional sessions of in-person dietary counseling with the registered dietician – 30 minutes at 1 month and 30 minutes at 3 months. Pre-existing knowledge of a Mediterranean diet was measured by the validated Mediterranean Diet Score instrument (MDS). Baseline height, weight, blood pressure and laboratory biomarkers were collected. At 1, 3 and 6 months, participants presented for a follow up appointment to assess compliance to the Mediterranean diet using the MDS, as well as a patient satisfaction survey, blood pressure and weight. Repeat laboratory biomarkers were performed at 3 and 6 months.

Results:

Enrolled participants had a mean age with standard error of 56.6 ± 1.7 for SOC and 57.2 ± 1.8 for EXP; 65.3% of SOC and 56.9% of EXP were male, and 20.4% of SOC and 35.3% of EXP had coronary artery disease. There were no significant differences between EXP and SOC with respect to blood pressure, lipid parameters, HgbA1C, or CRP. Participants in EXP achieved a significantly greater weight loss on average of 3.3 lbs vs. 3.1 lbs for participants in SOC, p=0.04. Adherence to the Mediterranean diet increased significantly over time for both groups (p<0.001), but there was no significant difference between groups (p=0.69). Similarly, there was no significant difference in diet satisfaction between EXP and SOC, although diet satisfaction increased significantly over time for both groups. The proportion of participants with high Mediterranean diet compliance (defined as MDS ≥ 9) increased significantly over time (p<0.001) – from 18.4 to 57.1% for SOC and 27.5 to 64.7% for EXP – however, there was no significant difference between the groups.

Conclusions:

Both traditional standard-of-care counseling and smartphone-based counseling were effective in getting participants to adhere to a Mediterranean diet in this US-based study of cardiology patients, and these dietary changes persisted even after counseling had ended. However, neither method was more effective than the other. This study demonstrates that the American cardiology patient can change to and maintain a Mediterranean diet with either traditional or smartphone app-based nutrition counseling.