Alex Dimitriu, MD

Menlo Park Psychiatry & Sleep Medicine

Weight loss and happiness - Serotonin and the carbohydrate connection

The bread rolls at restaurants may actually help you eat less... Serotonin is an essential neurotransmitter - and acted upon by many commonly known anti-depressants which boost its levels. It has a myriad of effects- ranging from creating a feeling of satiety, sleep, mood, anxiety,  pain, blood pressure, and sense of overall calm. The highest number of serotonin receptors are actually found in our gut.Tryptophan is one of 22 essential amino acids and is the essential precursor to the formation of serotonin.

Studies now show that having a moderate dose of (low fiber) carbohydrates, can have mood elevating effects, and actually reduce our sense of hunger and food consumption. The reason lies in the "plasma tryptophan ratio" - which affects which amino acids get through the blood brain barrier. Eat a protein rich meal - and all the amino acids equally compete to cross into the brain (so less tryptophan, and less serotonin). Eat a carbohydrate rich meal, and the insulin drives a lot of amino acids into muscles - leaving less competition for tryptophan to cross into the brain (so more tryptophan and more serotonin). The proof? Work by Judith Wurtman has demonstrated that people served a carbohydrate rich pre-meal drink "became less hungry and were able to control their calorie intake" and this effect was not achieved with a protein rich drink (less transported serotonin). Additional studies have found impaired tryptophan transport in fibromyalgia, as well as a tendency to over-eat carbohydrates in patients with depression and during periods of anxiety - which may be a form of self medication by enhancing serotonin levels. 

THE RECIPE:  For weight loss and happiness from the book :

"The Serotonin Power Diet" by Dr. Wurtman


1 - Have your carb snack on an empty stomach so there is no competition from other amino acids 
2- Snack on 25-35 grams of carbohydrate- with low fiber to speed up absorption
3- Protein content should be less than 4 grams, less than 3 grams of fat. Pretzels, chips, or crackers are a great option
4- Wait 20-40 minutes to feel the effect - don't keep eating!
5- Aim for more protein in the morning and more carbs with dinner, to reduce snacking, and enhance sleep.

Read more here:


Serotonin: What It is and Why It's Important for Weight Loss
Fat and Happy? Tryptophan Concentrations Reduced in Obesity
Brain serotonin, carbohydrate-craving, obesity and depression.Plasma tryptophan and other amino acids in primary fibromyalgia: a controlled study

MENLO PARK  PSYCHIATRY & SLEEP MEDICINE  650-326-5888

CONDITIONS TREATED: anxiety, depression, attention deficit disorder, insomnia, bipolar disorder, and treatment resistant depression.

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