What Was Jim Fixx’s Diet? Unpacking the Eating Habits of a Running Pioneer

In the 1970s, a quiet transformation took place in American health culture. At the center of this shift was Jim Fixx, a man whose running journey and best-selling book, The Complete Book of Running, helped ignite the jogging craze that swept the nation. While Fixx is widely celebrated for popularizing running as a path to longevity and wellness, many modern wellness enthusiasts are intrigued by another aspect of his lifestyle: his diet. What did Jim Fixx eat? Did his eating habits align with the fitness revolution he championed? And more importantly—did his diet help or hinder the very longevity he pursued?

This article dives deep into Jim Fixx’s diet, exploring its principles, typical foods, limitations, and how it reflected the nutritional understanding of his time. Discover how this influential figure approached food, the science behind his choices, and what we can learn from his dietary habits today—both the wisdom and the warnings.

The Man Behind the Movement: Jim Fixx’s Health Journey

Born in 1932, James F. Fixx was not always the poster child for health and fitness. In fact, early in life, he struggled with smoking, being overweight, and a family history of heart disease. His father died of a heart attack at just 43 years old—a fate Fixx was determined to avoid.

After taking up running at age 35, Fixx experienced dramatic improvements in his health. Within months, he lost weight, quit smoking, and felt more energetic than ever. His transformation inspired him to write The Complete Book of Running, published in 1977. The book became a national bestseller, selling over one million copies and helping launch the modern running boom.

But Fixx did more than just run—he also advocated for lifestyle changes, including improved eating habits. His diet became a cornerstone of his message on health.

Core Principles of the Jim Fixx Diet

While Jim Fixx didn’t publish a diet book or follow a branded eating plan, his dietary philosophy was clearly outlined in his writings, interviews, and documented eating habits. The core principles of the Fixx diet were deeply influenced by the health science of the 1970s and early 1980s.

1. Emphasis on Whole, Unprocessed Foods

Fixx was an early adopter of the belief that “natural” foods promote health. He favored minimally processed foods and believed in avoiding artificially flavored, preserved, or packaged items. This was relatively progressive for the era, pre-dating the modern clean eating movement by decades.

2. High in Complex Carbohydrates

The Jim Fixx diet was heavily carbohydrate-based, particularly complex carbs. Rice, pasta, potatoes, and whole grains formed the foundation of his meals. As a runner, he emphasized that carbohydrates were his primary fuel source. This aligned with prevailing advice for athletes at the time: “carbo-load” to boost endurance.

3. Vegetarian-Inclined, But Not Strictly Vegetarian

Fixx often described himself as a vegetarian or near-vegetarian, although records show he occasionally consumed fish and chicken. His plant-forward diet included large quantities of grains, legumes, fruits, and vegetables. He avoided red meat—particularly beef—believing it contributed to heart disease.

Key Plant-Based Ingredients:

• Brown rice and whole wheat pasta
• Lentils, beans, and split peas
• Raw and cooked vegetables (especially leafy greens)
• Fruits such as bananas, apples, and citrus
• Nuts and seeds in moderation

4. Low in Fat, Particularly Saturated Fat

In line with mainstream dietary guidance of the 1970s and 1980s, Fixx adhered to a low-fat diet. He avoided butter, cream, cheese, and fatty meats. He often used margarine instead of butter and chose skim milk over whole. This belief stemmed from research linking high-fat diets—especially those high in saturated fats—to heart disease.

5. Rich in Fiber

Fiber intake was high due to the abundance of vegetables, fruits, legumes, and whole grains. Fixx believed fiber helped maintain digestive health and reduce cholesterol levels. Modern science supports this, showing that dietary fiber reduces the risk of cardiovascular disease and supports gut health.

6. Minimal Sugar and Refined Foods

Fixx largely avoided sugar, sugary drinks, and highly refined products like white bread and candy. He viewed sugar as “empty calories” that could lead to weight gain and poor health. Occasional desserts were made with honey or fruit as sweeteners.

Typical Jim Fixx Meal Plan

Based on interviews and accounts from his contemporaries, we can reconstruct a typical day of eating for Jim Fixx. Importantly, this wasn’t rigid but reflected general habits and preferences.

Breakfast: The Carb-Powered Start

A typical Fixx breakfast included:

• A large bowl of cooked oatmeal or granola with skim milk
• Sliced banana or apple on top
• A slice of whole wheat toast with margarine and jam
• Black coffee or herbal tea (no sugar)

This meal was designed to provide sustained energy for morning runs and workouts.

Lunch: Plant-Based and Fiber-Rich

Lunch was often a hearty salad or grain bowl:

• Mixed greens, cucumbers, tomatoes, and carrots
• Cooked brown rice or whole wheat pasta
• Lentils or chickpeas for protein
• Lemon juice or a vinegar-based dressing (no oil or very little)
• Sometimes topped with a small portion of tuna or boiled egg

This combination delivered complex carbohydrates, plant protein, and fiber—ideal for supporting endurance.

Dinner: Simple and Wholesome

Dinner varied but typically included:

• A large baked potato or serving of brown rice
• Steamed vegetables such as broccoli, carrots, or green beans
• A small portion of fish (like salmon or cod) or occasionally skinless chicken
• Apple sauce or a fruit salad for dessert

While not strictly vegan or vegetarian, the meal emphasized plant-based ingredients.

Jim Fixx’s Beliefs About Diet and Longevity

Fixx firmly believed that a combination of running and healthy eating could prevent heart disease and extend life. In his book, he argued that heart disease was largely preventable through lifestyle choices. His diet was a direct extension of this philosophy.

He cited studies suggesting that diets low in saturated fat and high in complex carbohydrates reduced the risk of atherosclerosis and heart attacks. His advocacy helped popularize the idea that what you eat matters as much as how much you exercise.

Still, Fixx’s dietary views were limited by the scientific understanding of his time. For example:

• The dangers of trans fats—common in margarine, which Fixx used—were not yet widely recognized.
• The benefits of healthy fats (like those in avocados, nuts, and olive oil) were downplayed.
• The importance of protein quality and balance—especially for endurance athletes—was underemphasized.

These factors would later come under scrutiny as nutrition science evolved.

A Closer Look: The Controversy Surrounding His Diet and Death

Perhaps the most discussed aspect of Jim Fixx’s legacy is his untimely death. On July 20, 1984, Fixx died of a heart attack at the age of 52 while jogging in Vermont. His death shocked the nation—especially those who believed that running guaranteed a long life.

Questions naturally arose: If Fixx ran so much and ate so “well,” why did he die so young? This led to critical reevaluations of both his fitness routine and diet.

Genetics Played a Role

One critical factor was Fixx’s genetic predisposition to heart disease. His father’s early death was not an anomaly—Fixx himself had inherited a dangerous tendency toward coronary artery disease. Despite lifestyle changes, genetics can significantly increase risk, sometimes outweighing even the most disciplined habits.

Was His Diet Truly Heart-Healthy?

While Fixx’s diet had many positive aspects—high fiber, low saturated fat, rich in plants—it wasn’t without flaws by modern standards.

A notable issue: it may have been too low in healthy fats. Olive oil, omega-3 fatty acids from fish, and other heart-healthy fats were largely missing from his regimen. The 1980s low-fat movement led many, including Fixx, to avoid fats altogether—including beneficial ones.

Moreover, the widespread use of margarine, which contained trans fats, may have contributed to arterial inflammation and cardiovascular risk. Trans fats, now known to be harmful, were not banned until decades later.

Lack of Nutrient Balance

Fixx’s diet was excellent in complex carbohydrates and fiber, but potentially deficient in:

• Vitamin B12 (from lack of animal products)
• Omega-3 fatty acids
• Complete protein sources
• Fat-soluble vitamins (A, D, E, K), which require dietary fat for absorption

These deficiencies might not have been obvious in the short term, but over time, they could impact cardiovascular and metabolic health.

How Does the Fixx Diet Compare to Modern Nutrition?

Today’s understanding of nutrition has evolved dramatically since Jim Fixx’s time. While many elements of his diet remain sound, others have been updated or even reversed.

What Modern Science Confirms

Many of Fixx’s dietary principles hold up well:

Where Modern Advice Diverges

Today’s nutrition experts would likely recommend several modifications to the Fixx diet:

• Add healthy fats such as olive oil, avocados, nuts, and fatty fish.
• Focus on quality protein sources, especially for active individuals.
• Reevaluate reliance on processed low-fat substitutes (e.g. low-fat margarine with trans fats).
• Encourage occasional fermented foods for gut microbiome support.
• Pay attention to nutrient density, not just calorie sources.

Rather than cutting all fat, current guidelines emphasize the type of fat consumed—an important shift from the low-fat dogma Fixx followed.

Lessons from Jim Fixx’s Diet for Today’s Health Enthusiasts

Despite its limitations, the Jim Fixx diet offers valuable lessons for those seeking a healthy, sustainable lifestyle.

1. The Power of Whole Foods

Fixx’s commitment to whole, unprocessed foods remains one of his most enduring legacies. Eating foods in their natural state—fruits, vegetables, grains, legumes—supports health and reduces exposure to harmful additives.

2. Food as Fuel

For endurance athletes, Fixx taught us that nutrition supports performance. Carbohydrates are essential for sustained energy, and runners need to pay attention to their caloric and nutritional intake.

3. Lifestyle Matters

Fixx demonstrated that health is not a single habit, but a holistic lifestyle. Running, diet, stress management, and avoiding smoking all played roles in his transformation. Today, we call this approach “preventive medicine.”

4. Beware of Dietary Fads

Fixx’s diet reflected the nutritional trends of the 1970s and 80s—particularly the low-fat movement. His story underscores a crucial truth: even well-meaning dietary advice can become outdated. It’s essential to base eating habits on evolving science, not just popular trends.

Adapting Fixx’s Principles for the Modern Era

How can you honor Jim Fixx’s legacy while benefiting from contemporary nutritional knowledge?

Consider this modernized interpretation of the “Fixx-inspired diet”:

Breakfast (Updated)

• Oatmeal with almond milk, chia seeds, and berries
• A boiled egg or Greek yogurt for added protein
• Green tea or black coffee (unsweetened)

Lunch (Elevated for Balance)

• Quinoa or brown rice salad with chickpeas, kale, tomatoes, and cucumbers
• Dressed with olive oil and lemon juice
• Grilled salmon or tofu for omega-3s
• A handful of walnuts or almonds

Dinner (Heart-Healthy and Balanced)

• Baked sweet potato or whole grain pasta
• Steamed broccoli and carrots
• Grilled chicken, tempeh, or lentils
• Side of sauerkraut or kimchi for gut health

This approach maintains Fixx’s plant emphasis but adds nutrient diversity, healthy fats, and better protein quality.

Conclusion: Jim Fixx’s Diet—A Product of Its Time and a Foundation for the Future

Jim Fixx’s diet was revolutionary for its era—emphasizing whole grains, fiber, and plant-based eating while rejecting processed foods and saturated fats. It complemented his running regimen and reflected his sincere effort to beat poor genetics through lifestyle.

While his tragic death at 52 raises sobering questions, it does not discredit his message. Rather, it reminds us that health is nuanced. Genetics, nutrition science, individual needs, and environmental factors all play a role.

The Jim Fixx diet teaches us to be proactive about our health, to view food as medicine, and to continuously adapt as science evolves. His legacy endures not just in marathon finish lines, but in the everyday choices millions make to eat better, move more, and live longer.

Today, we can honor Jim Fixx by embracing the wisdom of his diet—its whole-food foundation, its mindfulness about heart health—while updating it with the best of modern nutritional science. That balance—honoring the past while embracing the future—is the true path to sustainable wellness.

As Fixx once wrote: “The miracle isn’t that I finished. The miracle is that I had the courage to start.” Whether it’s running your first mile or revamping your diet, the courage to begin remains the first, most vital step.

What was Jim Fixx’s diet primarily composed of?

Jim Fixx, best known as the author of “The Complete Book of Running,” followed a diet that reflected the health-conscious trends of the 1970s and 1980s. His eating habits emphasized whole grains, fruits, vegetables, and lean proteins, while avoiding refined sugars and saturated fats. He was a vocal advocate of reducing red meat intake and promoted plant-based foods as central to maintaining cardiovascular health and supporting endurance training. His dietary approach was largely low-fat and high in fiber, aligning with popular nutritional guidance of the era aimed at preventing heart disease.

Though not a strict vegetarian, Fixx consumed a predominantly vegetarian diet, often including oatmeal, brown rice, beans, and salads. He encouraged readers to minimize processed foods and focus on natural, unrefined ingredients. His choices were influenced by emerging research linking diet to heart health, of which he was acutely aware given his family history of heart disease. While his diet was considered progressive at the time, some modern nutritionists critique it for potentially lacking balance, particularly in healthy fats and adequate protein for an endurance athlete.

Did Jim Fixx eat meat, and if so, how much?

Jim Fixx did consume meat, though sparingly and selectively. He drastically reduced his intake of red meat after adopting a fitness-focused lifestyle in his 30s, believing that high saturated fat consumption contributed to heart disease. His meals typically featured fish and poultry as protein sources, especially baked or grilled preparations, while avoiding fried or fatty cuts. Fixx viewed lean animal proteins as acceptable within a balanced diet, but only when consumed in moderation and not as a dietary staple.

This approach reflected the evolving nutritional understanding of the time, when scientists were beginning to link high cholesterol and fat-heavy diets to increased cardiovascular risk. Fixx’s shift away from meat was both personal and public—he used his platform to encourage others to do the same. Still, his occasional meat consumption set him apart from more radical vegetarian or vegan advocates. Critics later argued that his diet’s lack of emphasis on quality fats and complete proteins might have contributed to nutritional gaps, particularly for someone engaged in intense daily running.

How did Jim Fixx’s diet support his running habits?

Jim Fixx’s diet was specifically tailored to fuel his endurance running, with an emphasis on complex carbohydrates for sustained energy. Foods like whole grains, oats, and starchy vegetables formed the foundation of his meals, providing the glycogen stores necessary for long-distance running. He typically ate large portions of carbohydrate-rich foods before and after runs, following advice common among runners of his era. Hydration and timing of meals were also priorities, ensuring he maintained energy levels without digestive discomfort during exercise.

While his diet supplied ample energy from carbs, it was relatively low in fat and moderate in protein—suboptimal by modern athletic standards. Today, endurance athletes are encouraged to consume adequate healthy fats and higher-quality protein to support muscle repair and overall metabolism. Fixx’s regimen, while effective for his training goals at the time, might not meet current recommendations for balancing macronutrients. Nonetheless, his eating pattern demonstrated the importance of intentional nutrition in athletic performance, a concept he helped popularize.

What role did breakfast play in Jim Fixx’s daily diet?

Breakfast was a cornerstone of Jim Fixx’s eating routine, typically consisting of a large bowl of high-fiber cereal, such as shredded wheat or rolled oats, served with skim milk and topped with fresh fruit. He often drank black coffee or tea with his morning meal and avoided sugary breakfast items like pastries or processed cereals. This nutrient-dense start to the day aligned with his philosophy of eating clean, natural foods that promoted digestive health and steady energy release, essential for his morning runs.

Fixx believed that beginning the day with fiber and complex carbohydrates set a positive tone for metabolism and physical activity. His breakfast choices were designed to be filling without being heavy, enabling him to exercise comfortably afterward. He frequently highlighted the importance of breakfast in his writings, noting its role in preventing overeating later in the day. While today’s nutrition science might suggest adding more protein or healthy fats for satiety and blood sugar control, Fixx’s morning meal was emblematic of his broader dietary principles.

How did Jim Fixx approach sugar and processed foods?

Jim Fixx was strongly opposed to the consumption of refined sugar and processed foods, which he considered detrimental to health and performance. He avoided sweets, sodas, white bread, and packaged snacks, advocating instead for whole, natural ingredients. In his books, he warned against the empty calories and potential metabolic harm caused by processed sugars and refined carbohydrates. His goal was to reduce inflammation, stabilize energy, and lower the risk of chronic diseases, particularly heart conditions that ran in his family.

Instead of processed sugar, Fixx favored natural sweeteners like fruit or honey in limited amounts. He emphasized reading labels and understanding food ingredients, a novel concept for many at the time. While he didn’t eliminate sugar entirely, his disciplined approach reflected a conscious effort to minimize artificial additives. This mindset contributed to the growing public interest in clean eating during the late 20th century. However, some modern experts caution that overly restrictive diets without professional guidance can miss key nutrients or create deficiencies.

Did Jim Fixx take any supplements as part of his diet?

While Jim Fixx did not advocate for extensive supplementation, he supported the use of certain vitamins and minerals to fill potential nutritional gaps. He was particularly interested in antioxidants like vitamin C and vitamin E, which were believed in his time to protect against cellular damage and support heart health. He also occasionally took B-complex vitamins to support energy metabolism, aligning with the belief that active individuals required more micronutrients. However, he always stressed that supplements should complement—not replace—a healthy diet.

Fixx was cautious about the commercialization of supplements and warned against relying on pills for health benefits without lifestyle changes. His recommendations were based on the limited scientific understanding of the era, long before the widespread supplement industry we see today. He acknowledged that well-nourished individuals might not need supplementation at all, especially if they consumed a varied, whole-food diet. While his measured approach was prudent then, current research suggests a more nuanced view of supplementation, especially for athletes with increased nutrient demands.

How has Jim Fixx’s diet influenced modern running nutrition?

Jim Fixx played a pivotal role in linking diet and exercise, helping to establish the idea that what runners eat directly impacts performance and longevity. His emphasis on whole grains, fruits, and vegetables laid the groundwork for modern clean eating trends in the athletic community. By sharing his personal journey—from a sedentary, unhealthy lifestyle to a disciplined runner—Fixx made nutrition accessible and relevant to the average person. His writing encouraged runners to treat food as fuel and to prioritize long-term health over short-term convenience.

While some aspects of his low-fat, high-carb approach have been revised by current science, his core message endures: intentional eating supports fitness goals. Today’s runners benefit from more comprehensive nutritional strategies that include balanced macronutrients, hydration, and timing, but Fixx’s influence is evident in the continued emphasis on whole foods and plant-based options. His advocacy helped launch the conversation about sports nutrition, inspiring both amateur runners and professionals to take their diets seriously as part of a holistic training regimen.