I'm a Greek Mediterranean diet expert. Here's my best advice for Americans who want to eat better on a budget.

Elena Noviello/Getty Images, Courtesy of Dr. Artemis Simopoulos.

• A Greek doctor and nutrition scientist says it is possible to eat healthy on a budget.
• She cooks beans a few times a week, and recommends choosing small portions of meat.
• At home, she uses a DIY spread made from 50% butter and 50% olive oil, to make her toast healthier.

This...