Dear DOCTOR Owen:

My doctor prescribed Meridia® so that I won’t re-gain the 100 pounds of weight I’ve lost during the last year. He told me that it is effective in preventing re-gain. I feel slightly more energetic since starting the medication. I also feel better and am less depressed. Does this medication stimulate my nervous system or increase my metabolism?

100 and Holding

Dear “Holding”:

Congratulations on your weight loss. All of the feelings you describe are probably from effects of the medication. Meridia® was released by the Food and Drug Administration (FDA) last year as adjunctive (additive to diet and exercise) therapy for the treatment of seriously obese patients. It has been shown in short-term studies to decrease hunger and improve satiety (fullness). Some question about increasing metabolism has been raised; in previous animal studies, it does seem to increase metabolism slightly.

Meridia® prevents the breakdown of two brain chemicals (serotonin and norepinephrine ) that can affect eating, mood, and metabolism:

• Stops the breakdown of serotonin, similar to many antidepressants on the market like Prozac, Zoloft®, Paxil®, and so on. Serotonin deficiency contributes to depression, loss of motivation, easy distraction, and decreased satiety. Certain foods, such as chocolate and sweets, cause the release of serotonin by the brain, resulting in a temporary improvement in mood. When they are eaten more and more, these foods eventually deplete serotonin, and contribute to the downward spiral of obesity and depression. Increasing serotonin reserves by these medications overcomes patients’ depression and helps them focus on the task at hand—dieting. This component of the medication is what is helping your mood.
• The other chemical affected by Meridia® is norepinephrine, which is similar to adrenaline. Norepinephrine builds up in the nerve fiber with Meridia®. Having more norepinephrine available “excites” the brain, giving patients a feeling of energy and alertness. The “energy” is translated to muscle movement, or “fidgeting,” which burns calories.

“Naturally” thin people tend to be nervous, fidget, and talk fast! They make more adrenaline-like chemicals than “naturally” obese people, who tend to be calmer and fidget very little.

These “metabolism” changes are very minimal-– comprising only 1%–3% of the basal metabolic rate (the energy used to run your internal organs without exercise). Since we use approximately a million calories/year, 1%-3% amounts to 10,000–30,000 calories/year. The loss of one pound requires “burning off” 3500 calories. Thus, this “metabolism” advantage is 3–8 pounds/year. Over 10 years, it amounts to 30–80 pounds!

Two articles in the International Journal of Obesity, Vol. 23, No. 10, 1009–1016 and 1017–1025, by researchers in Scotland and Denmark, respectively, review the above findings and previous research. They conclude that Meridia® may have its greatest benefit in maintaining lost weight because it prevents the decline in metabolism that accompanies not carrying around excess weight. For example, you lost 100 pounds. Now go pick up 100 pounds and carry it around all day. You will barely be able to get out of the chair—yet you did that effortlessly a year ago. That effort burned calories.

Many medical Diet Therapy clinics, such as mine, are involved in an FDA-sponsored, five-year study of Meridia® to see if patients maintain weight that was previously lost in a voluntary weight-loss program. After a year of observing patients enrolled in various programs in my clinic, I cannot honestly distinguish who is on the drug or the placebo. This supports the researchers’ conclusions (above) that the changes are small. After 5 to 10 years, however, small changes make huge differences.

For example, if in 1980 I had kept my meager savings in the stock market instead of investing in Louisiana oil-patch real estate, I would be writing this column in retirement aboard my yacht. But then, I wouldn’t have learned all of this! Like investing, successful weight management requires skill, patience, persistence, and a view of the long term. If Meridia® works for you, be ready to take it forever.