The Cookie Diet is a popular weight loss diet. It appeals to customers worldwide who want to lose weight quickly while still enjoying sweet treats.

It has been around for over 40 years and claims to help you lose 11–17 pounds (5–7.8 kg) in one month.

The diet relies on replacing breakfast, lunch, and snacks with nine Dr. Siegal brand cookies every day. In addition, you eat one meat and vegetable dinner.

This article provides a complete overview of the Cookie Diet, including its benefits and downsides.

  • Overall score: 0.79
  • Weight loss: 1
  • Healthy eating: 0
  • Sustainability: 2
  • Whole-body health: 0.25
  • Nutrition quality: 0.5
  • Evidence-based: 1

BOTTOM LINE: The Cookie Diet may result in short-term weight loss, but no studies support its effectiveness. It relies heavily on prepackaged cookies, is highly restrictive, and does not provide guidance on how to maintain weight loss without cookies.

The Cookie Diet is a weight loss diet that was developed in 1975 by former bariatric physician Dr. Sanford Siegal. He developed the cookies in his private bakery to help his bariatric patients control their hunger and stick to a reduced-calorie diet.

The diet attributes the appetite-reducing effects of the cookies to a secret blend of amino acids, which are the building blocks of protein.

Prior to being available online in 2007, the diet program was sold in more than 400 medical practices in South Florida. It has been used by millions of people worldwide from Hollywood stars and professional athletes to the average person.

According to the official Cookie Diet website, most people can expect to lose 11–17 pounds (5–7.8 kg) over one month on the diet.

The cookies come in several flavors, including chocolate brownie, cinnamon oatmeal, maple pancakes, and butterscotch.

The Cookie Diet is kosher and vegetarian-friendly but unsuitable for vegans, as well as those who must avoid gluten or dairy products.


The Cookie Diet is a weight loss diet that was developed by Dr. Sanford Siegal. It claims to help you lose 11–17 pounds (5–7.8 kg) in one month.

The Cookie Diet has two phases — weight loss and maintenance.

Weight loss phase

The weight loss phase is based on a principle called the 10x formula.

During this phase, you’re allowed to consume nine Dr. Siegal cookies per day, as well as a healthy dinner comprising lean meat or fish and vegetables.

The eating plan is spaced out as follows:

  • Breakfast: 2 cookies
  • Morning tea: 1 cookie
  • Snack: 1 cookie
  • Lunch: 2 cookies
  • Afternoon tea: 1 cookie
  • Snack: 1 cookie
  • Dinner: 250 grams of lean meat or fish and vegetables
  • Snack: 1 cookie

Each cookie provides 52.5–60 calories, and the dinner should provide 500–700 calories. In total, this adds up to approximately 1,000–1,200 calories per day.

There are no strict guidelines on how to prepare the dinner, though it’s ideal to cook the meat and vegetables in a way that keeps the calorie content low, such as baking, broiling, roasting, steaming, or sautéeing.

According to the diet website, you should not go without eating for more than 2 hours. It’s claimed that this will reduce your risk of feeling hungry, as well as boost your metabolism.

However, research suggests that smaller frequent meals do not significantly affect metabolic rate, compared with fewer larger meals (1, 2, 3).

In addition to the meal and cookies, dieters are advised to take a multivitamin supplement and drink eight glasses of water per day.

Exercise is not necessary during this phase, as dieters are already in a large calorie deficit. However, you may perform light exercise if desired, such as a 30-minute walk up to 3 times per week.

Weight maintenance phase

Once you have achieved your weight loss goal, you can move to the maintenance phase indefinitely.

The weight maintenance phase is as follows:

  • Breakfast: egg and vegetable omelet and berries
  • Snack: 1–2 cookies in between meals
  • Lunch: 250 grams of lean meat or fish and vegetables
  • Snack: 1–2 cookies in between meals
  • Dinner: 250 grams of lean meat or fish and vegetables
  • Optional snack: 1 cookie if needed

In addition to the eating plan, it’s encouraged to drink eight glasses of water per day and perform three 30–40-minute sessions of moderate to advanced exercise, though there are no specific exercise guidelines.


The Cookie Diet has two phases — a weight loss phase that you follow until you reach your desired weight and a lifelong maintenance phase.

There are several benefits to following the Cookie Diet.

Weight loss

First, it should help you lose weight, regardless of your current weight and gender.

On average, to maintain weight, men and women need to consume 2,500 and 2,000 calories per day, respectively. Reducing these daily amounts by 500 calories should contribute to an estimated 1-pound (0.45-kg) of weight loss per week (4).

Considering that the Cookie Diet provides just 1,000–1,200 calories per day, it should contribute to an even greater weekly weight loss.

Although studies have shown mixed results, some research has found that full or partial meal replacement plans may result in greater weight loss than conventional low calorie diets (5, 6).


Furthermore, the Cookie Diet is relatively cost-effective and convenient, as the cookies are pre-made and dinner is the only meal you need to prepare each day.

Still, there are currently no long-term studies on the Cookie Diet and weight loss, so more research is needed to assess its effectiveness and compare it with conventional reduced-calorie diets.


The Cookie Diet restricts calories, which should help you lose weight. It’s also convenient and cost-effective.

Though the Cookie Diet should help you lose weight, it has several significant downsides.

Unnecessarily restrictive

The diet does not factor in your specific nutritional needs, which are influenced by factors like your starting weight, age, height, or muscle mass. In addition, it’s highly restrictive and provides too few calories.

For healthy and sustainable weight loss, it’s recommended that women eat no fewer than 1,200 calories per day, and men no fewer than 1,500. Given that this diet restricts calories to 1,000–1,200 per day, it falls below these guidelines (7).

What’s more, though this significant reduction in calories may result in overall weight loss, research shows it could likewise lead to significant muscle loss (8).

Packed with processed food

Another downside of the diet is that it relies on processed foods and multivitamins to make up for the lack of real food. Moreover, due to its restrictiveness, following the diet could make it difficult to reach your daily needs for nutrients like fiber, iron, folate, and vitamin B12.

On the contrary, the best foods for weight loss and optimal health remain whole foods like vegetables, fruits, protein, complex carbs, and healthy fats, which are all nutrient-dense and have synergistic effects on your health.

It’s also important to note that the maintenance phase doesn’t provide guidance on how to make healthy long-term dietary changes to keep the weight off without relying on the cookies.

Unsuitable for certain dietary patterns

Lastly, the Cookie Diet is unsuitable for people following a vegan, dairy-free, or gluten-free diet, as the cookies contain milk and wheat.


Though it may help you lose weight, the Cookie Diet is highly restrictive, provides too few calories, and doesn’t provide guidance on how to make healthy and sustainable dietary changes.

The Cookie Diet is a weight loss diet claiming to help you achieve quick fat loss by replacing breakfast, lunch, and snacks with specially formulated cookies.

Though it’s convenient and may help you lose weight initially, it’s highly restrictive, provides too few calories, and does not provide guidance on how to make healthy long-term changes.

Consuming a varied diet based on whole foods is a better option for optimal health and long-term weight loss.