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The McDougall Program Cohort: The Largest Study of the Benefits from a Medical Dietary Intervention

Updated October 31, 2014

The Nutrition Journal on October 14, 2014 published the results of 1,615 patients who attended the McDougall Program in Santa Rosa, California.

Important Medical Findings Achieved in Seven Days from Eating the McDougall Diet

  • Average weight loss was 3.1 pounds while eating unrestricted amounts of food
  • Average cholesterol reduction was 22 mg/dL
  • An average decrease of 18/11 mmHg in blood pressure in patients with hypertension (140/90 or greater)
  • Nearly 90% of patients were able to get off blood pressure and diabetic medications

Please note that the more overweight and unhealthy the persons were at the beginning of the program, the more favorable were their results were at the end. For example, when cholesterol began at over 240 mg/dL, the reduction seen was 39 mg/dL, whereas cholesterol levels at less than 150 mg/dL at the beginning experienced an 8 mg/dL decrease in a week.

It Took Three Years to Get Published

All of the collected data from people attending the McDougall Program between 2002 and 2011 was analyzed in the year 2011 for this research project. After that, a written paper was submitted to some of the most respected medical journals, including the British Medical Journal and the Annals of Internal Medicine. We were very happy when the Nutrition Journal accepted our article because this is an “open access” publication, which means everyone can read the article for free. You will find papers published by the Nutrition Journal listed in the US National Medical Library ( Another plus about this journal is that they do not accept research done on animals; a statement of concern for animal rights. Their mission statement fits well with the McDougall mission: “The journal aims to encourage scientists and physicians of all fields to publish results that challenge current models, tenets or dogmas.”

 Click Here to Read the Entire Paper for Freecohort-9327622

Gain a Pound a Day on a Cruise or Lose Half a Pound a Day with Dr. McDougall

People are unable to lose weight because hunger is, by nature’s design, painful. Dieters are in denial of this biologic fact and as a result “they fail.” Attendees of the McDougall Program are encouraged to eat as much delicious food as they want, three or more times a day. They often go back to the buffet line for thirds and fourths. This kind of unrestricted eating on a cruise ship translates into seven pounds, or more, of weight gain in seven days. However, because of the composition of the McDougall meals—very low in fat and high in carbohydrate—people effortlessly, without any thoughts of deprivation, lose 3.1 pounds (1.4 Kg) on average per week. That could mean 12 pounds in a month and 150 pounds in a year. The Star McDougallers website page shows that this is the result for many people who once considered themselves hopelessly obese.


Is Seven Days Too Short to Be Meaningful?

One common criticism of our recently published paper is that long-term compliance and benefits are unknown. So what! The intention of the study was to report the effects of one week of healthy eating—no more and no less. What happens in the future is a matter for another scientific paper.

Many, but not all, patients continued to follow the diet after leaving us. I know from my 40 years of experience as a physician that the McDougall Program permanently changes many lives. Also a report from an independent analysis by investigators at Oregon Health & Science University (OHSU in Portland, OR) showed very high compliance after attending the McDougall Program in Santa Rosa, CA: 80% of people followed the diet 100% of the time for a year. (Behavioral changes maintained for more than six months are often permanent.)

This kind of dramatic, early success can be important for maintaining patients’ motivation to adhere to the diet in the future. These rapid results will also motivate physicians to prescribe diet therapy before resorting to the pharmacy in order to help their patients.

Most Benefits Were Not Reported

Our recent study did not record the subjective improvements seen in participants, including the relief from fatigue, arthritis, headaches, stomachaches, body aches, indigestion, and constipation. For most people the liberation from debilitating physical and psychological pains was far more appreciated than any of the changes in numbers (cholesterol, blood pressure, etc.) that were reported.

The study did document changes in numbers (biomarkers) that suggested improvement in the function of the heart, blood vessels, and kidneys. By giving credit only to the numbers, however, the big picture is often overlooked: This huge change in diet prescribed at the McDougall Program caused the removal of the burdens of food poisons, primarily animal foods and vegetables oils, that were sickening and killing our patients. For at least seven days, these 1,615 people were healing: Their minds and bodies were regaining lost functions and their appearances were improving. I have no doubt that most of them, once introduced to this alternative, continue the healing processes once they returned home.

Limitations and Strengths of the Study

A limitation of the study may be that those attending the McDougall Program may not represent the general population. These were self-selected people who had the time and money to travel to Santa Rosa, CA for 10 days. The financial cost for the Program likely reflects a higher income stratum. Higher incomes are commonly associated with other measures of success such as higher education levels. All of these factors may have contributed to the decision of participants to try a low-fat vegan diet.

However, a strength of the study is that complete raw data was used. By including essentially all attendees in the analysis, this method removes the important bias of selectively excluding unfavorable results that may have occurred during the McDougall Program.

More Research Is Not Needed

The McDougall Cohort is the largest database ever published on a closely supervised, physician-directed, therapeutic low-fat diet. No future publications of similar size are expected. The scientific research performed over the past century clearly and consistently shows the benefits of a diet based on starches with vegetable and fruits, and the harms caused by the consumption of animal foods and vegetable oils. There is no need for another study to be published in order for patients, physicians, health organizations, insurance companies, and government bodies to take long-overdue actions. This Nutrition Journal article provides a practical model for health promotion within the healthcare system: an intensive week-long residential educational program. We believe that this simple dietary approach can improve patients’ health, ultimately reduce healthcare costs, and help the world become a better place to live.