Understanding Weightloss: Serotonin
You’ve heard the statistics before…two-thirds of Americans are overweight and almost one-third are obese…at any one point in time, 30-40% of men and 50-60% of women are dieting…the list goes on and on. If I had to make up a statistic, I’d say 98% of us all have been on some sort of diet at some point in time (the remaining 2% are anomalies and probably aren’t reading this blog anyway). So, what’s the deal? Why do people jump from weight-loss program to weight-loss program with varying success? Being in the health and fitness industry, before medicine, I’ve concluded it’s partially due to being uneducated about our bodies. Even as a personal trainer, putting people through dozens of different programs, I didn’t truly understand how weight-loss worked. I was first taught that it was a simple equation: burn more calories than you consume and you’ll lose weight. Simple, right? Maybe in theory, however, reality was a totally different story. It wasn’t until medical school that I started putting more of the pieces of the weight-loss puzzle together. This blog entry will be the first of a series that will address different aspects of weight-loss and how to make you more successful at it.
First I’ll start with serotonin. Serotonin is a neurotransmitter that influences regulation of mood, appetite, sleep, muscle contraction, and some cognitive functions including memory and learning. Our bodies make serotonin from the amino acid tryptophan. When people go on low-carb diets (which are low in tryptophan), their serotonin levels drop and the brain interprets this as starvation. So, the natural thing to do is for the brain to signal that it needs more carbs (thus the craving for a large pizza all to yourself). My approach to this dilemma is to slowly drop the grams of carbohydrates one takes in, while at the same time slowly titrating up a dosage of 5-hydroxy-L-tryptophan (5HTP). 5HTP is a precursor to serotonin. It sits in between L-tryptophan and serotonin in the serotonin metabolic pathway. Therefore, it’s a great way to keep your serotonin levels up (carb cravings down) while you’re learning to diminish the amount of carbs (simple carbs especially) in your diet.
Some patients have asked why they couldn’t just take L-tryptophan instead of 5HTP (L-tryptophan tends to be a cheaper supplement than 5HTP) since it’s on the same pathway. The short answer is that you add more variables to the equation. L-tryptophan can’t cross the blood-brain barrier without a transport molecule. Once it does get across, it must be converted to 5HTP using an enzyme (tryptophan hydrolase) that can be inhibited by stress, insulin resistance, vitamin B deficiency, magnesium insufficiency, and oxidation associated with age. So, it’s just easier and more effective to use 5HTP.
Remember: let your doctor titrate your dosage! It can be tricky and optimal doses for weight-loss are on the high-end, so it should take a while to get your dosage up to that optimal area. Also, 5HTP in combination with selective serotonin reuptake inhibitors (SSRIs) like Prozac, Paxil, Zoloft, etc., could potentially (though never documented) cause serotonin syndrome. This can manifest as agitation, confusion, delirium, fast heart rate, sweating, and blood pressure fluctuations. Just because you can buy it over-the-counter doesn’t mean it can’t harm you if used improperly. Be safe.
In pursuit of health,
Dr. May
