The phrase "the guy who ate McDonald's for a year" most famously refers to John Cisna, a high school science teacher from Iowa who undertook a dietary experiment in 2013. The experiment was a project for his biology students to prove that poor diet and obesity are not solely the fault of fast-food companies but rather the result of poor individual choices. Though his initial goal was 90 days, Cisna was so successful that he extended the challenge to 180 days, consuming 540 meals exclusively from McDonald's.
John Cisna's McDonald's Diet: The 180-Day Experiment
Cisna's experiment was built on a very specific set of rules, which his students helped him create:
- Calorie-Controlled Intake: Cisna ate three meals a day, limiting his daily intake to 2,000 calories. He and his students used the nutritional information on the McDonald's website to carefully plan each meal.
- Nutrient Balance: The meal plans were designed to meet the Food and Drug Administration's recommended daily allowances for over a dozen key nutrients, including vitamins C and D.
- Regular Exercise: In addition to controlling his diet, Cisna walked for 45 minutes four to five times per week.
- Variety of Menu Items: He made an effort to try nearly all 133 items on the McDonald's menu over the 180 days, often including salads, oatmeal, and milk to balance out items like fries and burgers.
The Surprising Results of the Controlled Fast-Food Diet
At the end of his 180-day experiment, the results were astonishing to many. He not only lost weight but also saw dramatic improvements in his overall health markers.
- Significant Weight Loss: Cisna dropped a total of 60 pounds, going from 280 to 220 pounds.
- Improved Cholesterol: His cholesterol plummeted from 249 to 170.
- Lowered Triglycerides: His triglyceride levels dropped from 156 to 80, and his LDL (bad) cholesterol went from 170 to 113.
- Reduced Blood Pressure: His blood pressure dropped to a healthy 121/78 mmHg.
Cisna's success story demonstrates that a calorie-controlled diet combined with exercise can lead to weight loss and improved health, even when using fast food. His results stand in stark contrast to the unregulated bingeing seen in other similar experiments.
The Notorious 'Super Size Me' Experiment
The reason many people assume a year-long McDonald's diet would be catastrophic is due to the 2004 documentary, Super Size Me, directed by Morgan Spurlock. For his experiment, Spurlock ate only McDonald's for 30 days, with disastrous results for his health.
- Excessive Calorie Intake: Spurlock consumed an average of 5,000 calories a day, more than twice what Cisna ate.
- Minimal Exercise: Unlike Cisna, Spurlock deliberately reduced his physical activity to match the low-activity lifestyle of the average American at the time.
- Supersizing: A key rule for Spurlock was that he had to accept the "Super Size" option whenever it was offered.
- Undisclosed Alcohol Consumption: It was later revealed that Spurlock had a history of alcohol abuse and had concealed this from his doctors during filming, which likely contributed to his liver issues.
As a result, Spurlock gained 25 pounds, experienced mood swings, lethargy, and significant liver damage. The two experiments highlight the critical difference between moderation and indulgence.
Comparison: Cisna vs. Spurlock
| Aspect | John Cisna (The Teacher) | Morgan Spurlock (The Filmmaker) |
|---|---|---|
| Diet Duration | 180 days (half a year) | 30 days |
| Calorie Intake | Controlled to 2,000 calories/day | Uncontrolled, ~5,000 calories/day |
| Exercise | Walked 45 mins, 4-5 times/week | Deliberately reduced physical activity |
| Super Size | N/A (not required) | Required to accept "Super Size" offer |
| Key Outcome | Lost 60 lbs, improved health markers | Gained 25 lbs, serious health decline |
| Thematic Conclusion | Weight loss is about choices and moderation. | Fast food is harmful in excessive quantities. |
Life After the Experiment: John Cisna's New Role
After his successful experiment, John Cisna's journey didn't end. McDonald's took notice of his positive results and hired him as a brand ambassador. He traveled the country, speaking at schools and community groups, promoting his message of personal accountability and making healthy food choices within a fast-food context. However, this role and a promotional documentary titled 540 Meals: Choices Make the Difference drew criticism from those who believed it was an infomercial, downplaying the nutritional deficiencies and high sodium content of fast food. Cisna insists his point was never to promote an all-fast-food diet but to emphasize that conscious choices are key to managing weight. He has since continued his advocacy for balanced choices rather than promoting a specific diet plan.
Conclusion
The story of the guy who ate McDonald's for a year—actually a teacher named John Cisna who ate it for six months—serves as a compelling counter-narrative to the prevailing fast-food scare stories. While Morgan Spurlock's Super Size Me demonstrated the obvious dangers of uncontrolled, excessive fast-food consumption, Cisna's experiment showed that with strict calorie control, balanced food choices from the menu, and regular exercise, it is possible to achieve weight loss and improve certain health markers. This doesn't mean a diet of exclusively McDonald's is ideal or sustainable long-term, but it powerfully underscores the principle that managing calories and activity levels, not simply avoiding certain food types, is the primary driver of weight management. Cisna's legacy highlights the importance of personal accountability in nutritional decisions. A link to an article on his experience can be found at abc7.com/post/teacher-loses-60-pounds-while-eating-nothing-but-mcdonalds/705916/.
Frequently Asked Questions (FAQs)
Did a man really eat only McDonald's for a whole year?
No, the most famous person to do this experiment, John Cisna, a high school science teacher, ate exclusively McDonald's food for 180 days (six months), not a full year. He began in 2013 and documented his journey for a school project.
How did the teacher lose weight eating only McDonald's?
John Cisna lost weight by limiting his intake to 2,000 calories a day and combining this with regular 45-minute walks. He and his students carefully planned meals to include healthier options like salads and oatmeal to stay within his calorie and nutritional goals.
What happened to the man in Super Size Me?
The man in Super Size Me, Morgan Spurlock, ate an uncontrolled diet of only McDonald's for 30 days. He gained 25 pounds, experienced lethargy, mood swings, and liver damage. It was later revealed he had concealed a history of alcohol abuse, which likely contributed to his health issues.
Is it healthy to only eat McDonald's?
No, eating exclusively McDonald's, even with calorie control, is not recommended by health experts. While John Cisna proved it's possible to lose weight, the diet can still be high in sodium and lacking in micronutrients, fruits, and vegetables essential for long-term health.
Why was John Cisna's experiment different from Morgan Spurlock's?
Cisna's experiment was based on moderation, calorie counting, and exercise, while Spurlock's was an extreme example of overconsumption with minimal physical activity. Cisna focused on responsible choices, whereas Spurlock intended to show the harmful effects of unrestricted fast-food intake.
Did McDonald's pay John Cisna for his experiment?
McDonald's did not pay for the initial experiment. The food was sponsored by a local franchise owner. However, after his results gained national attention, McDonald's hired Cisna as a paid brand ambassador to speak about his experience.
Is a fast-food diet a good way to lose weight?
No. While calorie control is the key to weight loss, relying on fast food is not the most sustainable or nutritious method. The primary takeaway from Cisna's experiment is the importance of making wise food choices and managing calories, not that fast food is inherently healthy.
