The Tsia and Wadden study comparing commercial weight loss program results, included only 10 studies published over a 37 year period (1966-2003). Many good studies that did not have a randomized design, as well as numerous studies conducted at academic institutions using specialized protocols were not included.

• Only 2 of the 84 papers published in recognized medical journals using OPTIFAST^® were included. These papers were 10 and 13 years old.
• A study of 600 former OPTIFAST^® Program participants found 5 years after completing the program, approximately 50% of patients maintained medically significant weight loss, defined as a 5% or greater reduction in body weight compared to baseline weight.
• A data set of over 20,000 people who participated in the OPTIFAST program, showed
  • An average weight loss of 52 lbs
  • 12% average decrease in cholesterol
  • 12% average decrease in blood sugar
  • 9% average decrease in blood pressure

A picture may be worth a thousand words, but a snapshot of one corner of the Grand Canyon does not capture the scope of this amazing landscape feature. Similarly, a tightly focused research study may reveal interesting facts but miss the big picture. The recent review of commercial weight loss programs authored by Drs. Tsai and Wadden published in the January 2005 issue of Annals of Internal Medicine¹ is a case in point.

The authors of this study set out to compare the weight loss results achieved by individuals following various commercial diet programs “as typically offered to the public.” They chose to review only those studies that were based on randomized² trials of at least 12 weeks in duration, involved 10 or more adults, and included a one-year follow-up. These highly selective criteria resulted in a net analysis of only 10 studies and eliminated from consideration many good studies that did not have a randomized design, as well as numerous randomized, controlled studies conducted at academic institutions using specialized protocols.

When assessing the OPTIFAST^® medically supervised weight loss program, the researchers considered less than 3% of the available data-two studies that are 10 and 13 years old. There are 84 published studies with OPTIFAST in recognized medical journals, and many of these were authored by Dr. Wadden himself. This exclusion of the majority of the OPTIFAST Program studies from the commercial weight loss comparison study does not invalidate them or their results.

It is also notable that the studies included in the Tsai and Wadden study spanned a 37-year period (1966-2003). Because of this broad time period, their study captured data from weight loss programs that have substantially altered their treatment protocols since the original studies were published. For example, top OPTIFAST programs nationwide currently report attrition rates of 20-25%. This is approximately half the 46% attrition rate cited for the OPTIFAST Program in the commercial weight loss study. This higher figure was extracted from a 1992 study Dr. Wadden and colleagues published in 1992. Since that time, patient screening and assessment procedures for the OPTIFAST Program have become more structured and streamlined, resulting in much better retention rates.

OPTIFAST Program Outcomes Data: A Broader Picture of Success

Although individual results may vary, a 52 lb. average loss (21% reduction from entry weight) has been documented in over 20,000 people who completed 22 weeks (or about 6 months) in the OPTIFAST Program.

Long-term outcomes have been evaluated in a study of over 600 patients who completed the OPTIFAST Program. Novartis Medical Nutrition was the first company to publish 5 year outcomes data for this type of full meal replacement weight loss program. The data show that 2 years after completing the OPTIFAST Program, one out of four patients maintained 75% of their weight loss. Five years after completing the program, approximately 50% of patients maintained medically significant weight loss, defined as a 5% or greater reduction in body weight compared to baseline weight.

In addition to weight loss, the data set of over 20,000 people who participated in the OPTIFAST Program showed a 12% average decrease in cholesterol, a 12% average decrease in blood sugar, and a 9% average decrease in blood pressure, with even greater reductions in these values in patients diagnosed with elevated levels at baseline. The commercial weight loss comparison study was unable to include an assessment of these types of outcomes because most studies did not collect this data.

Taking Action

If you've tried losing weight without lasting success, perhaps you've been treating the symptom, not the causes, of obesity. Click here to Find An OPTIFAST Clinic Near You.

If you reside in the U.S.A. and are a health care provider interested in offering OPTIFAST for your overweight and obese patients, click here to become an OPIFAST^® provider.

¹Tsai AG, Wadden TA. Systematic review: An evaluation of major commercial weight loss programs in the United States. Ann Intern Med. 2005;142:56-66.

²A randomized study is one in which participants are assigned to one or more treatment groups by chance.