The Sonoma Diet is successfully sweeping across the U.S., in part due to its roots in the foods of the Mediterranean Sea and California’s lush Sonoma Valley, and partly since it pushes itself as a “lifestyle change” rather than a fad diet.

“You really have to be of the mindset that you want to change your life, and you don’t have to go to extremes to do it,” says Elisa Zied, MSRD, a spokeswoman for the American Dietetic Association. “Cutting your portions of energy-dense foods, incorporating more physical activity, and doing simple things are really going to make a difference over time…I was very excited that it was written by a registered dietitian. That’s always a good thing.”

Connie Guttersen, PhD, is a fan of the weight-loss plan that promotes the healthy and flavorful eating style of the Mediterranean and Sonoma Valley.

“Flavor is an important part of health and weight loss,” says Guttersen. “With most diets, you’re counting the days until it’s over. They don’t stick with you as a lifestyle.”

The plan has top 10 power foods: almonds, bell peppers, blueberries, broccoli, grapes, olive oil, spinach, strawberries, tomatoes, and whole grains, considered the core of the Sonoma diet. They are incorporated in many meals and recipes, and touted not only as delicious but also essential to good health and weight loss, in the right proportions.

Nutrient-rich foods are at the heart of the Sonoma diet, which steers clear of depriving people of essential carbohydrates, fats, and protein. Whole grain breads and cereals are allowed on the Sonoma diet, while certain foods containing saturated fat, added sugar, and refined white flour are discouraged.

“There’s a high expectation [in The Sonoma Diet] that people are going to be cooking a lot,” Zied says. “I like to encourage people to cook, but the truth is that a lot of people don’t have a lot of time.”

The Sonoma Diet is divided into three “Waves”: Wave 1 is a 10-day period in which dieters are urged to throw out or give away foods in their pantries containing refined flours, non-whole grains, hydrogenated and saturated fats, sugars, and any oil that isn’t extra-virgin olive oil, nut oil, or canola oil. Fruits are also prohibited in this wave in order to wean the body from sugar. Dieters can eat certain vegetables, lean meats, seafood, limited dairy, some grains, three daily servings of olive or canola oil, a small amount of nuts, black coffee, tea, and an unlimited number of herbs and spices.

“The first wave is the most extreme, the most low-calorie,” says Zied. “I don’t know anyone who’s followed the program, but I’d be surprised if they didn’t lose weight.”

Wave 2 of the Sonoma diet encourages more gradual weight loss. Wave 2 allows the same foods in Wave 1, but adds fruit, more vegetables, fat-free yogurt, some sugar-free sweets, an occasional piece of dark chocolate, honey, and some wine. Dieters are encouraged to stay on this phase of the diet until they reach their target weight.

Wave 3 promotes the same principles of healthy eating in Waves 1 and 2 but recommends boosting servings of fruits and vegetables and indulging in an occasional treat such as butter, dark chocolate, dessert, and soda.

The Sonoma diet also endorses physical activity.