Healthline diet score: 3.46 out of 5

The Pritikin Diet and Exercise program, also known as the Pritikin Program or Pritikin Principle, was a top selling diet book in the late 1970s, and it’s still popular today.

The basis of the program is a low fat, high fiber diet along with a daily exercise routine. It promises to help you manage your weight, reduce — or even reverse — your risk of heart disease, and make you feel younger than ever.

While advising dietary and exercise modifications for disease prevention is standard today, this philosophy was controversial in the 1970s and 1980s, when diet and exercise were not believed to be the main cause or way to prevent heart disease and poor health.

This article reviews the Pritikin Diet, including its weight loss effectiveness, other benefits, and downsides.

diet review scorecard

• Overall score: 3.46
• Weight loss: 2
• Healthy eating: 4
• Sustainability: 3.5
• Whole body health: 4.5
• Nutrition quality: 4
• Evidence-based: 2.75

BOTTOM LINE: The Pritikin Program promotes an unprocessed, low fat, and high fiber diet along with daily exercise and stress management. Still, it’s very low in fat and has a long list of restrictions, which may make it difficult to follow long term.

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What it is

The Pritikin Program was developed in the 1970s by Nathan Pritikin as a healthy lifestyle to aid weight loss and improve heart health. The diet emphasizes eating unprocessed, low fat, and high fiber foods along with getting daily exercise.

Though Pritikin wasn’t a medical doctor or health professional, his passion for a healthy lifestyle stemmed from his observations on public health during World War 2, as well as his own health issues.

Originally, it was believed that heart disease was related to prolonged stress, with treatment involving medication and a low stress lifestyle. However, heart disease rates decreased post-war despite being a time inundated with high stress levels.

Therefore, Pritikin grew curious about the true origin of these diseases. He also observed a key difference in the nutritional quality of wartime food rationings — they were low in fat and cholesterol and high in fiber.

To test his theory, he ignored his doctor’s advice and treated his heart disease with diet and exercise and without medication or rest. After reversing his heart disease, he continued his research and published dozens of successful results in renowned medical journals.

Until his death in 1985, Pritikin published numerous diet books, such as “The Pritikin Program For Diet and Exercise” and “The Pritikin Permanent Weight Loss Manual.” Furthermore, he opened the Pritikin Longevity Center in California, which is still in operation today.

Claiming to be the healthiest diet on Earth, the Pritikin brand encourages whole, unprocessed foods with an emphasis on low fat varieties, regular exercise, and maintaining a healthy mind-body connection through journaling, laughing, and other healthy habits.

Summary

The Pritikin Diet was developed by Nathan Pritikin in the 1970s. The diet promises to lower your risk of heart disease and other chronic diseases by focusing on eating a low fat, high fiber diet comprising mostly unprocessed food.

How it works

The Pritikin Program is based on three main categories — the Pritikin Diet, the Exercise Plan, and Healthy Mind and Body.

The Pritikin Diet

The Pritikin Diet emphasizes whole, unprocessed foods that are low in fat and high in fiber. Approximately 10–15% of calories should come from fat, 15–20% from protein, and 65–75% from complex carbs.

The plan is based on a stoplight system with a list of “go,” “caution,” and “stop” foods.

“Go” foods include fruits, vegetables, whole grains, starchy vegetables, legumes, fish, lean protein, and low fat, calcium-rich foods like fat-free yogurt.

“Caution” foods should be limited, but you can still eat them on occasion. These include oils, refined sugars (e.g., syrups and fruit juices), and refined grains (e.g., white bread, pasta, and rice).

Finally, “stop” foods should be eaten no more than once per month and include animal fats (e.g., butter), tropical oils (e.g., coconut oil), processed oils (e.g., hydrogenated margarine), organ and processed meats, whole fat dairy, and processed treats.

To help you with your new diet, Pritikin offers a meal delivery service called Pritikin Foods.

The Exercise Plan

The Pritikin Exercise Plan focuses on three main areas — cardiovascular conditioning (aerobic exercise), strength training, and flexibility (stretching).

Though you’re expected to learn the details of the plan at the Pritikin Longevity Center, several general tips are suggested, including:

• Cardiovascular conditioning: 30–90 minutes each day at least 6 days per week (7 days per week if you have diabetes)
• Strength training: two or three 20-minute training sessions per week
• Stretching: stretch for 10 minutes each day for at least 10–30 seconds per stretch

For personalized recommendations, the program recommends visiting the Pritikin Longevity Center for a full assessment and customized exercise plans.

Healthy Mind and Body

Managing chronic stress and anxiety are key components of the Pritikin Program, as prolonged stress can have detrimental effects on your physical and mental well-being.

The program’s wellness center — The Pritikin Longevity Center and Spa — is a health resort located in Miami, Florida that offers wellness retreats.

It also offers various cognitive and behavioral practices, such as relaxation training and cognitive behavioral therapy, to achieve “stress hardiness,” which is believed to help improve your ability to handle stress.

It’s based on four main personality traits that you can achieve:

Commitment: an overall commitment and curiosity about yourself, your work, and those around you

Control: an internal belief that you can control how you respond to any situation or life change

Challenge: a positive attitude toward change and growth

Connection: an unwavering belief that those closest to you value and understand you

Along with this, the program encourages creating a strong social support system of friends and family, daily journaling, laughing regularly, eating nutritious foods, and exercising each day to manage stress.

Summary

The three main components of the Pritikin Program include eating a low fat, high fiber diet, exercising daily, and learning to better manage your stress levels.

Food lists

The Pritikin Diet has a clear and organized list of foods to eat, limit, or avoid. Foods to eat are labeled “go” foods, while foods that should be limited or avoided are “caution” and “stop” foods.

Foods to eat

Foods on the “go” list include:

• Fruits and vegetables (4–5 servings of each per day): aim for a variety of colors and types; eat them in their whole form either fresh, frozen, or canned without syrup
• Complex carbs (5 or more servings per day): whole grains (whole wheat breads and pastas, brown rice, oatmeal, rye, quinoa, barley, millet, etc.), starchy vegetables (potatoes, sweet potato, yams, winter squashes, etc.), and legumes (black beans, kidney beans, chickpeas, lentils, peas, etc.)
• Nuts and seeds: limit servings to no more than 1 ounce (28 grams) per day
• Dairy (2 servings per day): nonfat cow’s milk, nonfat yogurt, and fortified soymilk
• Lean protein (no more than one serving per day): skinless white chicken or turkey, lean red meat (bison, venison), and a large emphasis on plant-based proteins, such as legumes and soy products (tofu, edamame)
• Fish (no more than one serving per day): fresh or canned (unsalted) fatty fish, such as salmon, sardines, herring, mackerel, and trout
• Eggs: up to two servings of egg whites per day (no yolks); you may have more than two servings if this replaces other animal proteins
• Beverages: water as your main beverage; no more than 400 mg of caffeine per day from unsweetened tea (preferably green or herbal tea) or filtered coffee (removes diterpenes that may increase LDL (bad) cholesterol)
• Artificial sweeteners: no more than 10–12 packets of Splenda or Stevia each day
• Herbs, spices: all herbs and spices are allowed and should replace added sugar, fat, and salt

You’re also encouraged to get most of your protein from plant-based foods, such as tofu, edamame, beans, peas, and lentils.

Furthermore, if you’re trying to lose weight, you’re advised to eat unlimited vegetables and high fiber foods (e.g., cooked oatmeal, brown rice) and limit higher calorie foods, such as nuts, seeds, breads, and crackers.

Foods to avoid

Foods that should be avoided completely or limited to once per month include:

• Animal fats and processed oils: butter, chicken fat, chocolate, coconut oil, cocoa butter, hydrogenated and partially hydrogenated vegetable oils, lard, margarine, palm oil, palm kernel oil, shortenings, etc.
• Processed and high fat meats: organ meats and processed meats (e.g., bacon, sausage, ham, bologna)
• Whole fat dairy: all cheeses, cream cheese and other processed varieties, whole fat milk, whole fat yogurt, sour cream, etc.
• Nuts: only coconuts should be avoided due to their high saturated fat content
• Other foods: egg yolks, fried food or foods cooked in oil, nondairy whipped toppings, high fat pastries and desserts, salty snack foods, etc.

In addition to following the brand’s food list, it’s recommended to enroll in the program’s wellness workshops and cooking classes to learn how to prepare healthy meals, grocery shop, and order healthy items at restaurants.

Summary

Approved “go” foods include unprocessed vegetables, fruit, whole grains, and mostly plant-based proteins. Off-limit or restricted foods include highly processed meats, whole fat dairy, and other high fat foods.

Does it work for weight loss?

Though weight loss is not the primary goal, you can easily lose weight on the program.

The Pritikin Diet focuses on whole, unprocessed foods and emphasizes foods high in protein and fiber. Foods high in protein and fiber take longer to digest, which helps promote feelings of fullness and reduces hunger (1, 2, 3, 4).

The diet also strictly limits foods high in fat, sugar, and salt, which tend to be higher in calories (5).

Along with this, it encourages daily exercise and stress-reducing activities. Combined, these behaviors are linked to better weight management (6, 7, 8).

Overall, the program encourages a high volume of daily exercise paired with whole, low calorie foods. This will likely create a calorie deficit and ultimately lead to weight loss.

Summary

The Pritikin Diet focuses on low calorie foods that are high in fiber and protein, which may help curb your appetite. In addition, regular exercise and stress management paired with a healthy diet have been linked to successful weight loss.

Other benefits

Along with weight loss, there are other potential benefits to the Pritikin Program.

Backed by science

The Pritikin Program is one of the few branded diets with research to back its benefits. Still, most research studies were published between the 1970s and 1990s. However, a few modern research studies are available.

In a 2007 study, 67 participants attended the Pritikin Longevity Center for 12–15 days and experienced an average 3% decrease in their body mass index (BMI), as well as a 10–15% decrease in blood pressure and cholesterol levels (9).

In another 14-day study, 21 children with overweight or obesity with an average age of 13 on the Pritikin Diet and Exercise program experienced significantly lower markers of inflammation and a 7.8% and 6.0% average decrease in systolic and diastolic blood pressure, respectively (10).

Interestingly, the weight of the participants did not significantly change, but their risk of heart disease decreased. This suggests that the Pritikin Program may be effective among those who aren’t looking to lose weight (10).

In a 2014 review, the authors noted that following a mostly plant-based, low fat, and high fiber diet, such as the Pritikin Diet, is associated with better heart health, as it lowers cholesterol levels (11).

In particular, the Pritikin Diet discourages animal and plant fats high in saturated fats, which are linked to poorer heart health in some studies. Still, the diet encourages foods high in omega-3s, which are a type of unsaturated fat linked to improved heart and brain health (12).

Despite these results, all studies took place at the Pritikin Longevity Center, which calls into question whether the Pritikin Program is as effective without access to the health specialists and wellness retreats the center offers.

No calorie counting

The Pritikin Diet emphasizes nutritional quality over calories.

Instead of sticking to a set calorie goal, the diet focuses on eating fiber- and protein-rich foods that promote fullness and are naturally lower in calories.

This may help you become more in tune with your hunger and fullness signals and feel more satisfied on the diet.

Focus on lifestyle changes

The Pritikin Program focuses on whole body lifestyle changes.

The program encourages its followers to address all areas of health, such as eating a nutritious diet, exercising regularly, getting enough sleep, practicing mindfulness, and reducing stress.

Instead of promising a temporary fix, they focus on changes that you can adopt for the rest of your life, which increases the likelihood of success.

Summary

Reseaerch has shown that the Pritikin Diet decreases cholesterol and other markers of heart disease. What’s more, its focus on long-term lifestyle changes and nutritional quality rather than calories is a benefit to the program.

Downsides

Though the Pritikin Program has many redeeming qualities, there are some potential downsides.

Vilifies fat

One major downside of the Pritikin Diet is its low fat recommendations. The Pritikin Diet recommends that only 10–15% of daily calories come from fat, compared with public health recommendations of at least 20–35% (13).

Low fat diets are highly controversial due to the majority of research showing benefits of fat in the diet — especially those high in unsaturated fats (12, 14).

Interestingly, a 2016 study found a 27% higher likelihood of metabolic disease with low fat diets that comprised less than 15% of total daily calories, despite eating around 500 fewer calories per day, compared with those who ate a higher fat diet (15).

This calls into question the healthfulness of the Pritikin Diet, especially since most of the available studies on this diet lasted only a few weeks. Therefore, long-term research is warranted.

Plus, most research concludes a diet higher in unsaturated fats and low in processed foods will likely confer the most health benefits. Benefits of the Pritikin Diet likely come from eating minimally processed foods, limiting saturated fats, and eating a high fiber diet (16).

Finally, it should be noted that the Pritikin diet is also low in protein.

Someone following the low end of the protein recommendation for the Pritkin Diet — 10% of total calories — may not reach the minimum protein requirements of 0.36 grams of protein per pound (0.8 grams per kg) of body weight per day for sedentary people.

Physically active people have higher protein needs and may struggle to get enough protein on this diet. Pregnant and breastfeeding women, as well as older adults, also have higher protein needs. Thus, the Pritikin diet may not be appropriate for these populations (17, 18, 19, 20).

Inaccessible

Despite having the diet and exercise guidelines available on their website, most research on the benefits of the diet has been observed while attending the Pritikin Longevity Center.

Considering most people do not have the time, money, or ability to attend the center, this makes the program largely inaccessible.

Hard to maintain

The Pritikin Diet includes a large list of foods to avoid, including many that are normally eaten on a daily basis.

This leaves very little room for flexibility, and some people may find the diet difficult to follow long term. It also ignores other aspects of eating like tradition, culture, celebration, and enjoyment of flavors.

Positive lifestyle changes are most successful when a person is motivated, finds enjoyment in the new behaviors, and believes they can maintain them long term (21, 22, 23).

Considering the large number of food restrictions paired with the large time commitment for exercise, this may not be motivating or sustainable for everyone.

Summary

Downsides of the Pritikin Diet include its low fat recommendations, high cost, time commitment, and long list of food restrictions.

The bottom line

The Pritikin Diet is a low fat, high fiber diet focused on minimally processed foods. Along with the diet, the Pritikin Program emphasizes daily exercise and reducing your stress levels.

The diet’s emphasis on whole, unprocessed foods, daily exercise, and stress management are all scientifically backed ways to help you lose weight in a safe, slow, and healthy manner.

However, it’s very low in fat and restricts a long list of foods, which may be hard to sustain long term and not provide your body with enough fat or protein to function properly.

If you’re interested in trying the Pritikin Diet, it’s best to speak with your healthcare provider and a registered dietitian to ensure you’re meeting your needs.