Participants sought for weight-loss study to help understand why one diet doesn't fit all

Christopher Gardner

Researchers at the Stanford Prevention Research Center are seeking participants for a 12-month weight-loss study aimed at understanding why people on the same low-fat or low-carbohydrate diet have different rates of success.

The study, titled One Diet Does Not Fit All, will also try to identify the traits that account for these differences — factors such as genetic influences, insulin resistance, gut microbes, sleeping and eating habits, and depression or other psychological issues.

Participants will be assigned randomly to either a very low-fat or very low-carbohydrate diet for 12 months. They will be required to attend weekly classes at Stanford for the first three months, once every other week for the following three months, and once a month for the remainder of the study. Participants must also be willing to have fasting blood samples drawn four times during the 12-month period and participate in online and written surveys. They will receive all test results at the end of the study.

Men and women (only pre-menopausal) who are overweight or obese, in general good health and between the ages of 18 and 50 are eligible to participate in the study, which is part of a five-year project funded by the National Institutes of Health and the Nutrition Science Initiative. Last year, 200 participants were enrolled in the study. This year, the research team hopes to recruit at least 135 participants for the spring cohort and 135 for the fall cohort. The team also hopes to recruit at least 135 participants for next year's spring cohort.

Participants will have extensive support and guidance from a team of Stanford health professionals and learn about healthy diets that may help their weight-loss efforts.

Christopher Gardner, PhD, professor of medicine, is the principal investigator. Gardner and his colleagues have investigated the potential health benefits of various diets for decades. Some of their previous research indicated that some people have more success on one diet over the other, possibly because of factors such as genetic influences and insulin resistance. For example, people with high insulin resistance appeared to fare better on a low-carbohydrate diet. The researchers want to find out if this knowledge can be used to predict what diet would work best for an individual.

They also hope to determine what factors drive a person to stick to a specific diet and succeed at losing weight while on it. Such factors might include counseling and smartphone applications that track what they eat.

For a complete list of inclusion criteria, visit To determine eligibility for this study, complete a brief online survey at

For more information, contact Jennifer Robinson at

The study is also supported by the NIH’s National Institute of Diabetes and Digestive Kidney Diseases (grant R01DK091831).

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