Why would you want to give up food for a liquid meal replacement? There are actually several reasons why this might be a good idea. In some cases Optifast is used for the purposes of very short term weight loss, for example by patients preparing for a surgery in which losing weight may actually reduce the risk and speed recovery (e.g. weight loss surgery, other gastrointestinal surgeries). This effective weight loss method might also be used by women who want to increase their chances of becoming pregnant in the context of fertility treatment. The most common use of Optifast is as part of a long-term medically-supervised weight management program. In this case, the use of a meal replacement is step one of a multi-phase approach. In the present discussion I will examine the role of Optifast in the program that we offer in our clinic.
First, a quick description of the product. Optifast is a meal replacement that can be used as a total substitute for food, providing all of the basic nutrition that one needs in a very low calorie package. The Canadian version provides 900 calories per day. That does not sound like a lot (it isn't), but the formula includes adequate amounts of protein, fat and carbohydrate for the average person -- medical supervision is necessary, because there are some cases in which this isn't true.
In our program, Optifast is offered as a "choice," one of several treatment options. The main reasons that an individual chooses this route is its simplicity and efficacy. In other words, taking 4 liquid meals ("shakes") at 4 hour intervals during the day is pretty straightforward and, given the small amount of calories consumed, the resulting weight loss can be quite dramatic. So patients select this approach because they are highly motivated to get off to a fast start with a safe and structured solution.
Of course, giving up eating comes with certain costs. This is a practical method, not a gourmet one. The taste of liquid meal replacements is not surprisingly quite bland. Most people adapt fairly quickly, finding ways of preparing it to their own taste, and some people even come to like it. There are social inconveniences as well, such as not being able to join in a meal with others, or having to cook but not eat what one has prepared. Physically, there is an adaptation period, several days in which one may feel tired and hungry. These costs are short-term, however, and easily handled by most people.
Some people are skeptical about the long-term effects of using meal replacements, and for good reason. One is not about to stay on such a product forever, so what happens when one stops? In many cases, people who use such products, lose substantial amounts of weight and then go back to food, quickly regain their weight. They end up feeling disappointed and discouraged and question the value of the product. The key point is as follows: meal replacements on their own have absolutely no long-term usefulness. Most people need professional support to guide them back to food, and towards the long-term behaviour changes needed to ensure weight loss maintenance.
So why not skip the "artificial" products and go straight to working on the behaviour changes? That certainly works for some people, but for others the intial simple, structured and effective meal replacement phase is a great way to get started. In a well-designed treatment program, the transition back to food will be slow, and will allow the patient to find a way of eating (and exercising!) that fits their preferences and lifestyle.
This is a complex question that should be discussed with the health professionals supporting you in your weight loss efforts. There is no one-size-fits-all approach, so you must find the one which is right for you.
Stephen Stotland, Ph.D.