What Is the Sonoma Diet?

The Sonoma Diet, created by registered dietitian Connie Guttersen, is a weight loss program based on portion control and eating only those foods from an approved list. It is framed around 10 "power" foods: whole grains, almonds, bell peppers, tomatoes, broccoli, grapes, spinach, blueberries, strawberries, and olive oil. Even though whole grains top the list, the plan is overall lower in carbs than many other diets.

Guttersen's books, "The Sonoma Diet" and "The New Sonoma Diet," explain her philosophy. She says that she named her diet after the wine-country region of California and was inspired by the Mediterranean diet. The diet is based on the Mediterranean region's traditional foods, where residents tend to live long, healthy lives. It features some of the "power foods," including olive oil and whole grains, along with fish, legumes and nuts, and plenty of fruits and vegetables.

What Can You Eat?

The Sonoma Diet is structured in three phases, called waves. Wave one lasts for 10 days and is the most restrictive phase. It is followed by wave two, in which users aim to reach their ideal weight. Wave three focuses on maintaining that weight.

Approved foods include lean proteins consumed through each wave, small amounts of low-fat dairy, and vegetables. Which type of vegetables you can eat depends on the tier category and which wave you are in.

What You Need to Know

During the 10 days of wave one, the diet is highly restrictive. Portion sizes are relatively small. This phase is designed to break bad habits and achieve the following goals:

• Promote fast weight loss by limiting carbs and calories
• Wean users off sugar and reduce carb cravings
• Teach portion control
• Provide familiarity with the foundational foods of the eating plan

Although carbs are not specifically counted, wave one menus have approximately 40 grams of usable (net) carbohydrate. This is consistent with the beginning phase of many low-carb diets and would be considered ketogenic for most people (meaning they are burning more fats than carbs).

This diet can work for you if you prefer to eat vegetarian, gluten-free, or low-fat. As with almost any diet, check with your health care provider if you have a medical condition (such as heart or kidney disease) that could be affected by your diet. If you have diabetes, it's important to monitor your blood sugar levels and adjust carbohydrate levels accordingly.

Lean Proteins

These include eggs, seafood, poultry (without skin), soy products, and lean cuts of beef or pork—all protein sources low in saturated fat. The types and amounts of lean protein don't change from wave to wave.

Dairy Products

There is a shortlist of permissible dairy products in the first wave of the Sonoma Diet. Low-fat cottage cheese can be used as a protein. Up to one cup of fat-free milk per day is allowed (whole-grain cereal with milk is a recommended breakfast), as is one ounce of parmesan or mozzarella cheese. In wave two, one cup of plain, fat-free yogurt can be added.

Low-Starch Vegetables

There are three tiers of vegetables on the Sonoma Diet.

• Tier one includes many of the vegetables on the regular low-carb vegetable list; artichokes, pea pods, chili peppers, carrots, and beets are some of the excluded veggies. On the first wave, only these tier one vegetables are allowed.
• Tier two vegetables essentially comprise the rest of the low-carb vegetables, except for pea pods. In wave two, one serving of these can be included daily.
• Tier three vegetables are starchy, including winter squashes, corn, sweet potato (or yam), taro, and peas (including pods). In wave two, one of these can also be included daily. Potatoes are not allowed in waves one or two, and they should be eaten only occasionally in wave three.

Beans

Although legumes are a good, plant-based source of protein, they are limited to one daily half-cup serving during wave one.

Nuts and Nut Oils

During wave one, use nut oils (or olive or canola oil) for cooking and snack on small servings of nuts, for a total of up to three servings per day. In wave two, two tablespoons of peanut butter can be used as a protein. Or have one tablespoon as part of a snack. Nut serving sizes include:

• Almonds: 11
• Peanuts: 14
• Pecans: 10 halves
• Walnuts: 7 halves

Olive Oil and Condiments

As on the Mediterranean diet, Guttersen recommends cooking with olive oil and using it as a dressing. Condiments and sauces that avoid added sugars and saturated fats are key. 

Whole Grains

During wave one, two servings of whole grains are allowed each day (one seems to be mandatory). During wave two, three or four daily servings are permitted; two are mandatory. Whole grain servings must be 100% whole grain and can consist of:

• Whole grain bread: Must say 100% whole wheat or other whole grain, and every grain listed on the label must say "whole." Each slice of bread must have at least 2 grams of fiber. Bread, including cracked wheat, is even better.
• Whole grain, high fiber cereals: Cereals must also be entirely whole grain. Additionally, each serving should have at least 8 grams of fiber. This means that the cereal must have added bran. For example, Total is a whole-grain cereal, but it doesn't have enough fiber to qualify.
• Whole grain pasta: Again, make sure it is totally whole grain. A serving is one half-cup. Soba noodles, which are 100% buckwheat, are one whole-grain option.
• Cooked whole grains: These could include barley; brown, red, black, or wild rice; bulgur; oats (rolled oats, groats, or oat bran); quinoa; wheat berries, or cracked wheat. A serving is one half-cup.
• Popcorn: As part of a snack, popcorn can be included if air-popped and without butter.

Sweets

As with all low-carb diets, added sugars are to be avoided; nothing sweet is allowed during wave one. Small amounts of sweetener or diet soda may be consumed if you are having an especially rough time. Still, they are generally discouraged and considered contrary to the goals of the early phase. Some sugar-free treats are allowed in wave two and full-fat sweets (rarely) in wave three.

Fruit

Even though strawberries and blueberries are on the Sonoma Diet's list of power foods, no fruit is allowed during wave one, not even these berries. In wave two, enjoy two servings of fruit per day. A serving is a small piece of whole fruit or half a cup.

Refined Grains

These are to be avoided on all waves of the Sonoma Diet. They include processed grains, or foods containing them, and refined grains or foods containing them. That means any grain without the word "whole" listed before it on the label.

Saturated Fats

Saturated fats are kept to a bare minimum on all three waves by keeping proteins lean and avoiding processed foods such as crackers, chips, and cookies.

Alcohol

No alcohol is allowed during wave one. In wave two, up to six ounces of wine a day are permitted.

Sample Meal Plan

With the Sonoma Diet, you do not have to count calories, carbs, or fat grams because of the types of foods you eat. Instead, portion control is built in according to plate size. You must have the following:

• A bowl that holds 2 cups of liquid
• A 7-inch plate
• A 9-inch plate

Guttersen recommends eating three meals a day with an occasional snack if you need it. The plates and bowls must be measured to meet the exact requirements. According to Guttersen, a small difference in diameter can make a big difference in the amount of food you consume. Wave one meals are dished out as follows:

• Breakfast: Eat either a serving of protein and grains on the 7-inch plate (some vegetable is allowed) or whole-grain cereal and milk in the bowl.
• Lunch: Fill the 9-inch plate with a little more than half vegetables and the remainder protein.
• Dinner: Use the 9-inch plate and fill it with 50% vegetables, 30% protein, and 20% grains.

Keep in mind, this is not an all-inclusive meal plan, and if following the diet, you may find other meals that work best for you. You are allowed one medium or two thin slices of buckwheat, rye, barley, oat bread, or bread made from a mixture of those flours at lunch. Three days worth of wave one meals, which are very portion-limited, might look like this:

Day 1

• Breakfast: 2 egg omelet with mushrooms, peppers, and cheese
• Lunch: 1 cup chicken breast mixed with cucumbers, peppers, tomatoes, and cheese
• Dinner: 1 cup of lamb; garden salad

Day 2

• Breakfast: 2 poached eggs
• Lunch: 2 cups shrimp mixed with radish, garlic, cucumber, cheese, tomato; a small drizzle of olive oil
• Dinner: 6 ounces white fish; asparagus

Day 3:

• Breakfast: Oat flakes with low-fat milk
• Lunch: 2 cups cooked turkey breast; green beans
• Dinner: 1 cup chicken breast; broccoli; almonds

Pros and Cons

Pros

Simple and Practical

The strongest case for the Sonoma Diet is that it is straightforward. It does not require you to count grams or calories, and the size of your plate is used for portion control. Once you have a good sense of foods to eat and avoid, this diet is pretty simple because the dishes you use take care of all the counting, measuring, and portioning.

Positive

The Sonoma Diet emphasizes what you do eat rather than what you don't, though only to a certain extent. The list of forbidden foods is familiar to most low-carb diets.

Structures

Some low-carb diets lack structure. For those who want more guidance, the Sonoma Diet delivers—though it may be too much for some people.

If you're looking for a diet plan that offers guidance and education while keeping things simple, the Sonoma Diet may be a good option for you. But there are several aspects of the diet that can be concerning. If you dig into the recommendations, you might find some parts that will not work for you.

Cons

Restrictive

It unnecessarily restricts fruits and vegetables and is too low in calories for many people. Getting enough of your daily recommended vitamins and minerals might be challenging from the reduced calories and limited food choices.

Forbidden Foods

The Sonoma Diet emphasizes whole foods, which are both laudable and optimal. However, this is going to be a significant change for most people. Most diets give you a few "outs" in terms of sugar substitutes, more fats, or extra foods. Many of these are not allowed on the Sonoma Diet.

Secretly Low-Carb

The author claims that grains are "the heart and soul of the diet." However, the Sonoma Diet has fewer grain servings than the Dietary Guidelines for Americans recommends.

The recommended carb levels are consistent with other reduced-carb plans. Wave one menus come to about 40 grams of usable carb per day. None of the wave two menus are over 100 grams (some are as low as 69). That's low-carb by any standard. In fact, this diet proves that low-carb diets can be high in fiber and have a variety of foods, which almost all low-carb diet authors advocate.

Is the Sonoma Diet a Healthy Choice for You?

While the Sonoma Diet is similar to several low-carb plans, it also was inspired by the nutritious Mediterranean diet. It is mostly nutritionally balanced, yet its first phase is quite restrictive. Although the Sonoma Diet calls whole grains a power food and says it is not a low-carb diet, it shares many similarities to other low-carb plans.

The USDA suggests five to 10 servings of grains per day, depending on total calorie intake, while the Sonoma Diet allows only two in wave one (and four in wave two). The Sonoma Diet also eliminates fruit from wave one, while the USDA recommends fruit as part of a daily, balanced diet. The remainder of the Sonoma Diet's foods is more consistent with government guidelines since they emphasize vegetables and lean proteins.

As noted, this diet is relatively low in calories, especially in wave one. The USDA recommends a daily calorie intake of 1600 to 3000 calories for weight maintenance, depending on age, sex, and activity level. To lose weight, you'll need to reduce your calories. To determine your calorie target, try this calculator.

Health Benefits

Educational

The books talk about getting a variety of phytonutrients and antioxidants, partially through "power foods." Whole foods are emphasized, and very few processed foods are recommended, which is always a good sign. All of this information can benefit you in the long term as your diet becomes more of a lifestyle in which you understand how to make good choices.

General nutrition

This diet emphasizes whole grains, lean proteins, and (some) vegetables and limits saturated fats and refined carbs. For this reason, it could help some people learn to eat healthier, whole foods and avoid less filling, more processed foods.

Focuses on Enjoying Food

As you learn more about it, you will notice that this diet emphasizes eating slowly and savoring food. This can help you feel fuller and get more enjoyment from your meals rather than feeling deprived. Also, a glass of wine is allowed for dinner after the first 10 days, which can feel like a bit of reward.

Effectiveness

Followers of this diet will likely lose weight on wave one because it cuts out lots of foods and lowers calorie intake. Wave two is easier to follow but still fairly restrictive and will probably be effective for many users.

Health Risks

Very Low in Calories

Wave one menus are 900 to 1100 calories for women and 1100 to 1300 for men, with 200 to 300 calories added in wave two. Depending on size and activity level, this is too low for most people in the first phase. Even after that, many people may have a hard time with the restrictions. Within a few days, it's possible to become ravenous, and this isn't sustainable.

The other problem is that there is very little guidance on what to do when you're hungry. The advice for "a small snack (plain raw vegetables) to tide you over" doesn't work well when you're ready to sink your teeth into the nearest chair. It seems a bit ridiculous, but cutting carbs and calories to such low levels can have that effect.

Limits on Vegetables

Since the Sonoma Diet limits volume (via plate size), it limits low-starch and high fiber vegetables more than almost any other diet. For example, one cup of cooked spinach almost fills half of a 9-inch plate. Likewise, a healthy, low-calorie, high nutrition breakfast of two eggs on a mound of vegetables won't fit on a 7-inch plate. 

This may be an unintended consequence, but when you try to follow the wave one guidelines in your meals, you will keep bumping up against this limitation. Additionally, vegetable serving sizes actually shrink by half after the first 10 days.

Sustainability

Although wave three of the diet allows "indulgences" such as potatoes, pretzels, and the occasional dessert, this is still a challenging eating plan which might be hard for many people to sustain. Feeling deprived on a diet can cause some people to quit and fall back into previous eating patterns and regain the weight.

A Word From Verywell

If you're looking to lose weight, the Sonoma Diet might work for you. But know that the first wave is very restrictive and could be difficult. You could choose to apply some of the diet's principles and not others, or even skip right to the Mediterranean diet as a healthy, sustainable way to eat that just might help you lose weight too.

If you feel you need the structure of a program like the Sonoma Diet, do check with your health care provider first to help you consider whether this is the right choice for you. After all, everyone's body is different. Remember that other factors also matter for weight loss, such as exercise, sleep, and stress management.