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The McDonald’s Diet

Published by Cheryl Mussatto, MS, RD, LD on Sep 8, 2015

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You may have read or heard about the high school science teacher, John Cisna, from Iowa who had three of his students do a semester project featuring him eating nothing but food from McDonalds for 90 days. The purpose of this experiment was to see if he could lose weight and how it would affect his health.

In September 2013, John Cisna, who was obese weighing 280 pounds, wanted to see if it was possible to eat only fast food, yet by controlling his calorie level and balancing nutrients, could he actually lose weight in the process. What he found out was a resounding “yes.”

Here is what Cisna did:

  • He would eat as close to but no more than 2,000 calories a day
  • He tracked 15 different key nutrients each day to make sure he was meeting the recommended dietary allowances (RDA’s) for his age and gender
  • He would eat all meals – breakfast, lunch, dinner – only at McDonalds
  • His students would plan each meal for him using nutritional information of food items on McDonalds website
  • He tried to purposely eat almost all foods offered on the menu over the time period
  • He would incorporate exercise by walking 45 minutes a day

What he discovered after 90 days and eating 540 meals of nothing but food from McDonalds was that he lost excess weight and gained positively in his health parameters. In fact, he experienced such a significant health improvement he decided to continue the diet for an additional 90 days or for a total of 180 days. Here is what happened to him healthwise:

  • He lost a total of 60 pounds
  • He lost 21 inches off his chest, waist and hips
  • His cholesterol went from 249 mg/dl to 170 mg/dl
  • His Triglycerides went from 156 mg/dl to 80 mg/dl
  • His LDL, the bad cholesterol, went from 170 mg/dl to 113 mg/dl
  • His blood pressure lowered to 121/78 mmHg

How is this possible and what is the lesson to be learned here?

Cisna says that his goal in having his students do this project was to help them learn how to make educated decisions when it comes to choices and what you eat. By using critical thinking skills, it is possible to make proper choices and have a good outcome. The key was carefully planning food choices to stay within the set calorie limit and meeting the daily RDA for each of the 15 nutrients. By following an appropriate diet along with moderate exercise, it worked. His weight came off, his health improved and he did it by following scrupulously what his students had planned each day for him.

Should all of us do what Cisna did and eat only at McDonalds for 3-6 months? No, it is not necessary to go to that extreme. The lesson to be learned here is what we decide to eat from day to day or meal to meal, is a choice. It’s our choices of what we eat that make the difference. It’s not that McDonalds has any special foods that promote weight loss, it’s a matter of our own personal choices of what we eat and of how much of the food we eat. This experiment could probably been done with any other fast food chain, but to McDonalds credit, they have one of the more diverse menu options of a fast food restaurant, ranging from high-fat, high-calorie foods to healthy salads and grilled meat wraps.

The main message here is through careful planning, educating yourself on food and nutrition and making mindful choices along with regular exercise, you can make a positive difference in your health. You can enjoy all kinds of food, even McDonalds on occasion, as long as you keep within a calorie level that fits your individualized calorie and nutrient needs and balance that with adequate exercise. It’s still best to eat food in their natural state as much as possible and greatly limit processed and fast food. In the meantime, remember it’s all about choice – make your dietary choices wisely.

This article was originally featured on Dr. Samadi’s website ©. To read more, follow this link.


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Cheryl Mussatto, MS, RD, LD

Cheryl Mussatto MS, RD, LD is a registered dietitian with a master’s degree in Dietetics and Nutrition from the University of Kansas and a bachelor’s degree in Dietetics and Institutional Management from Kansas State University. She is a clinical dietitian for Cotton O’Neil Clinics in Topeka and Osage City; an adjunct professor for Allen Community College, Burlingame, KS where she teaches Basic Nutrition; and is a freelance writer and blog contributor for Dr. David Samadi, Urologic Oncologist Expert and World Renowned Robotic Surgeon in New York City. Cheryl is also the author of The Nourished Brain, The Latest Science on Food’s Power for Protecting the Brain from Alzheimers and Dementia and The Prediabetes Action Plan and Cookbook, both available on Amazon in Kindle and paperback editions.