From a biological perspective, the sensation of hunger is a pretty complex physiological response that involves the brain decoding messages about blood sugar, fat stores, energy needs and nutrient availability. However, there is a common denominator to hunger – and that is the messages themselves, or more specifically, the chemicals that are responsible for relaying all those messages. Those chemicals are called neurotransmitters. Mountains of clinical evidence and research have shown that we can control hunger by altering the levels of key neurotransmitters in the brain using amino acid therapy.
Two of the most important neurotransmitters in regards to hunger are serotonin and norepinephrine. Serotonin is a neurotransmitter that is often associated with mood; new research is showing that it is also likely responsible for cravings, especially for sugars, sweets, carbohydrates and soda as well as increased appetite. Serotonin is made from an amino acid derivative called 5-hydroxytryptophan (5-HTP), which is derived from the amino acid tryptophan.
Norepinephrine is made from dopamine (which itself is made from the amino acid tyrosine and/or L-dopa) and plays many roles it the body. It along with epinephrine is responsible for the “fight-or-flight” response to stress which allows you to act or react to stressors. Norepinephrine also affects alertness, arousal, decision making, attention, focus as well as the appetite center of the brain.
Picture from Marty Hinz, MD.
Imbalances in either serotonin or norepinephrine can cause increased cravings and/or increased appetite/hunger. Likewise, consuming an imbalanced amount of 5-HTP or L-tyrosine can also lead to increased hunger and cravings. Unfortunately, almost everyone’s diet is deficient in L-tryptophan/5-HTP.
To make up for this, many people that have cravings or increased hunger/appetite try to take 5-HTP as a supplement. Common sense tells us this should help. Unfortunately the body doesn’t always work by common sense. Taking 5-HTP without the proper balance of other amino acids can actually make the underlying neurotransmitter imbalance worse, which can make existing symptoms worse (including hunger) and even create other symptoms of neurotransmitter imbalance.
However, taking the right blend of 5-HTP along with L-tyrosine and other cofactors necessary to achieve optimal neurotransmitter function CAN dramatically reduce appetite and cravings. In fact, this is one of the most powerful therapies many people use to help them lose weight and keep it off.
If you’re interested in how and why this works see our series on the Chemistry of a Craving.
