Peanut Butter Diet


The peanut butter diet is a diet plan developed by Holly McCord, nutrition editor of Prevention magazine, a popular health and nutrition magazine. The diet allows consumers to enjoy peanut butter every day while still achieving their weight-loss goals. The diet is appealing because it offers a wide variety of nutrients, while allowing the dieter to enjoy peanut butter, a satisfying “comfort” food.

The diet promotes weight loss, lower cholesterol, and reduced risk of heart disease and diabetes for consumers who stay on the meal plan. The eating plan consists of two separate caloric intakes, one for men (2,200 calories per day) and one for women (1,500 calories per day).

Some consumers have reported that the diet is easier to follow than other popular diet plans. Because peanut butter tastes good and is simple to add to daily menus, dieters have no difficulty staying on the plan and being consistent. In the year 2000, Kraft Foods conducted a survey to determine which foods Americans were regularly stocking and consuming. Out of 100 common food items, peanut butter came in fourth. Eggs, granulated sugar, and flour came in first, second, and third place, respectively.


The roots of the peanut butter diet can be traced to research that was conducted at Brigham and Women's Hospital in Boston, Massachusetts. Nutrition researchers Kathy McManus and Frank Sacks, M.D. worked with overweight patients over several years. During their meetings with patients, they discovered that some overweight individuals were unsuccessful at keeping weight off for any length of time when following low-fat diet plans.

Peanuts and peanut butter.

Peanuts and peanut butter.

Later in their careers, McManus and Dr. Sacks conducted research that compared the effects of calorie-controlled moderate-fat and low-fat diets in obese adults. The result of their research was surprising. Their studies suggested that calorie-controlled diet plans containing moderate amounts of fat, including peanut butter, may be a factor in losing weight.

In their study, McManus and Dr. Sacks assigned 101 men and women, whose average weight was 200 pounds, to one of two study groups. One group was told to limit their fat intake to only 20% of their daily calories. The individuals in the second group had a daily fat allowance of 35%. The participants in the 35% group ate fat that came from foods that are rich in monounsaturated fat. These foods include peanut butter, olive oil, nuts, and avocados. Both study groups limited their intake of foods that were high in saturated fat such as cheese, butter, or red meats. In addition, both study groups were given the same caloric intake: women ate 1,200 calories and men ate 1,500 calories per day.

The study results were informative. Both groups lost an average of 11 pounds during the first six weeks. However, twice as many moderate-fat consumers (peanut butter dieters) were able to stay with the diet and were able to maintain their weight loss for a period of 18 weeks. On the other hand, the lowfat dieters had twice the amount of participants who dropped out, and the remaining participants regained about five pounds. McManus suggested that the peanut butter dieters were more successful because they enjoyed their food choices more than the moderatefat group, and that individuals can stick to a diet plan only if they feel satisfied by the foods they are consuming.


The peanut butter diet is largely based on portion control. Men are allowed three servings of peanut butter per day, while women can consume two servings per day. For this diet, a serving is two level tablespoons of peanut butter.

Consumers need not measure peanut butter with a level measuring tablespoon, since this can be time consuming and impractical if travel interferes. The book recommends simply placing a ping-pong ball in the kitchen. Then, consumers use a regular kitchen spoon to remove peanut butter from the jar. As long as the amount of peanut butter on the spoon is no larger than a ping-pong ball, this is considered an acceptable portion. However, it is recommended that dieters measure two tablespoons of peanut butter at least once or twice to familiarize themselves with appropriate portion size. Dieters may choose any brand of peanut butter that appeals to them. They may choose either natural peanut butter brands or emulsified varieties.

The diet plan is very simple. Consumers include peanut butter in two of their meals or snacks in convenient ways, such as spreading it on toaster waffles or an English muffin. It is also recommended that consumers take a 300–500 mg calcium supplement to meet daily calcium requirements. The peanut butter diet book includes several recipes and four weeks of meal plans for both men and women. The book also includes recipes for several desserts, including s'mores, a favorite childhood treat, or a peanut butter sundae. The inclusion of desserts makes the diet extremely easy to follow, prevents feelings of deprivation, and helps dieters integrate everyday foods in their diet. The menu plans and recipes are the mainstay of this diet plan and are extensively discussed in the peanut butter diet book.

A typical menu plan is as follows:

The author of the peanut butter diet also recommends getting plenty of “Vitamin X,” also known as exercise or regular physical activity. The plan encourages consumers to exercise as much as possible, but states that even 10 or 15 minutes of activity is better than doing no exercise at all. The peanut butter diet book includes a chart of typical exercises and the number of calories burned during each activity. The book also features some strength training moves, which are called “The Basic Six.” These six movements work all of the body's major muscle groups. Exercises in the Basic Six include squats, overhead presses, bicep curls, and other basic movements.


In 2002, updated guidelines were released from the National Cholesterol Education Program (NCEP), which is part of the National Institutes of Health (NIH). In their report, the NCEP stated that many changes in the way Americans prevent and treat heart disease must occur in order for them to stay healthy. The creator of the peanut butter diet states that many of these dietary changes are addressed within the diet's guidelines.

The NCEP guidelines suggest that consumers become aware of a set of symptoms referred to as Syndrome X. This cluster of symptoms may dramatically increase the risk of heart attack. The peanut butter diet addresses many of these concerns due to the presence of heart-healthy fats in peanut butter.

Another suggestion raised in the NCEP report was for consumers to follow a nutrition plan that is low in saturated fat. The peanut butter diet accomplishes this because it allows up to 35% of calories to come from total fat, provided that fat comes from mostly unsaturated sources.

The NCEP suggests that consumers aim to reduce high or borderline high triglycerides. Studies show that diets rich in peanut butter may aid in reducing triglyceride levels.

A disease that causes an abnormally high level of glucose (sugar) to build up in the blood.
Glycemic index (GI)—
An index that ranks foods that contain carbohydrates on the effect they have on blood sugar levels after the food is consumed.
High-density lipoprotein (HDL) cholesterol—
A type of cholesterol in the blood that is considered to be good for the body. The higher the HDL level, the lower the risk of coronary artery disease.
Kidney stones—
A small, hard mass in the kidney that forms from chemical deposits. Kidney stones can be extremely painful and are often difficult to diagnose.
Low-density lipoprotein (LDL) cholesterol—
A type of cholesterol in the blood that is considered to be bad for the body. High levels of LDL are a risk factor for heart disease.
Monounsaturated fat—
This type of fat is found in olive, peanut, and canola oils. It is also found in nuts, seeds, and avocados.
Increased body weight caused by an excessive accumulation of fat.
Saturated fat—
The type of fat that raises bad cholesterol and is linked to higher levels of cholesterol, heart disease, and other chronic diseases.
Syndrome X—
A group of common disorders that produces a high risk of cardiac disease.
Total cholesterol—
The total amount of cholesterol in the blood. Cholesterol is a fat-like substance made in the body and present in many foods.
Triglycerides are produced by the body and are the major form of fat.

Finally, the NCEP report stated that consumers should attempt to increase HDL (this type of cholesterol helps reduce LDL, the unhealthy type of cholesterol) levels. HDL levels should be at least 40 mg/dL. Research suggests that diets rich in peanut butter do not reduce HDL levels as do low-fat diets.


Peanuts and peanut butter contain more protein than any other nut or legume. Because peanut butter contains mainly monounsaturated and polyunsaturated fats, it is thought to be a heart-healthy food that may reduce cholesterol and the risk of coronary artery disease when included in a healthy diet.

When peanut butter is added to a meal or food containing carbohydrate, it lowers the overall glycemic index of the meal or snack. The glycemic index was developed in the early 1980s by researchers at the University of Toronto. The index ranks foods that contain carbohydrates based on the effect they have on blood sugar levels after the food is consumed. Each food is then assigned a number. Foods that rank high on the GI should be eaten in moderation, since these foods tend to cause a spike in blood sugar levels. This increase causes insulin levels to increase. Too much insulin may result in high blood pressure and increased risk of heart disease.

Not only is peanut butter a comfort food, it is also loaded with nutrients. Peanut butter is rich in folate, zinc, magnesium, potassium, copper, and vitamin E. It also contains two naturally occurring compounds called resveratrol and beta-sitosterol. These compounds are believed to fight cancer and combat heart disease. Peanut butter also contains fiber, which encourages bowel regularity and helps boost weight-loss efforts.

The peanut butter diet is effortless to follow. Recipes provided in the book are plentiful, informative, and easy for the average consumer to prepare. Peanut butter can be added to protein drinks or carbohydrates such as toast, waffles, muffins, and oatmeal, and can be combined with fruit and other foods to maximize variety and prevent boredom. The peanut butter diet can easily be followed if a person travels a great deal. Peanut butter is readily available and is easily stored in plastic containers or in its original jar. This allows the dieter to plan meals and customize menus for ultimate flexibility.


This diet plan is not recommended for everyone. As always, consumers should check with their physician before starting any type of diet or nutrition program. It is important for patients to avoid the diet if they are allergic to peanuts. If the patient is an older adult and/or has swallowing problems, the diet should be avoided since peanut butter may become caught in the throat. Individuals with high triglycerides should also avoid the diet or check with a physician before starting the diet plan. Finally, pregnant and/or breastfeeding women with a history of allergies should also check with their doctors before choosing this diet. The diet may cause a sensitization to peanut butter in newborns or infants.



Research and general acceptance

No formal studies or data exist regarding the general acceptance of this diet. The diet was featured extensively in Prevention magazine publications, suggesting that subscribers and readers may have been more likely to try the diet compared to nonsubscribers and nonreaders.

Research was conducted independently by Prevention to determine the effectiveness of the Peanut butter diet. An article titled “Fight Fat with Peanut Butter—Real Life Success Stories” was featured in the November 2002 issue of Prevention. Successful participants who lost up to 27 pounds during a field trial and were maintaining the loss were featured. As a group, Colleen Pierre (a registered dietitian and associate professor of nutrition at Johns Hopkins University) and her colleagues lost a total of 140 pounds over five months. None of the participants became bored with the diet or with eating peanut butter. The study participants were also pleased to find that their cholesterol levels dropped while they were on the diet. This added benefit underscored the study conducted by the Pennsylvania State University, whose research suggested that when included in a healthy diet, peanuts and peanut butter lowered bad LDL and total cholesterol by 14% and 11%, respectively.

See also Fad diets .



McCord, Holly. The Peanut Butter Diet. New York: St. Martin's, 2001.


Alper, C. M., and R. D. Mattes. “Peanut Consumption Indices of Cardiovascular Disease Risk in Healthy Adults.” Journal of the American College of Nutrition 22, no. 2 (April 2003): 133–41.

McManus, K., L. Antinoro, and F. Sacks. “A Randomized Controlled Trial of a Moderate-Fat, Low-Energy Diet Compared with a Low-Fat, Low-Energy Diet for Weight Loss in Overweight Adults.” International Journal of Obesity 25, no. 10 (October 2001): 1503–11.

National Cholesterol Education Program. “Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Panel III) Final Report.” Circulation 106, no. 25 (December 17, 2002): 3143–421.


“The Peanut Butter Diet.” Men's Health, May 29, 2003. (accessed April 12, 2018).

Deborah L. Nurmi, MS

  This information is not a tool for self-diagnosis or a substitute for professional care.