In Part 1 of The Chemistry of a Craving, we established that brain chemicals called neurotransmitters are responsible for those strong, urge-type cravings (especially for sweets and soda) that control many people. The basic biochemistry goes something like this: the neurotransmitters serotonin and norepinephrine are involved in controlling your mood, as well as the appetite center of your brain. When your body senses that it doesn’t have enough serotonin, it tries to make more. In order to increase serotonin levels in the brain, your body needs more of the amino acid tryptophan, the major precursor of serotonin.
Tryptophan ® 5-HTP ® Serotonin
Tryptophan competes with other amino acids for entry into the brain. Unfortunately, compared to other amino acids, tryptophan is at low levels in most foods. This means that under normal conditions, the amount of tryptophan that gets into the brain is very low.
However, the body has a remarkable way of getting around this obstacle. When you eat sweets or carbohydrate-rich foods, high amounts of insulin are released, accelerating the removal of sugar and amino acids other than tryptophan from the blood, leaving larger amounts of tryptophan to be transported to the brain to make more serotonin. The brain is happy again and you experience short-term relaxation, calmness and satisfaction–which provide further positive reinforcement for eating sweets and carbohydrate-rich foods. As a result, obese people frequently consume carbohydrates rather than other foods in order to subconsciously enhance tryptophan uptake into the brain and achieve “feel good” levels of serotonin. This is wonderful until the effect wears off and the cycle starts all over again–a reaction that can happen in a matter of minutes. The process is a double-edged sword; you feel good after eating carbohydrates, but it makes you crave more leading to weight gain. Unfortunately, this process will continue until your body’s neurotransmitters levels are balanced.
Interestingly, this relative serotonin deficiency remains even with substantial weight loss; meaning the cravings continue even if you do manage to lose weight. This is just one more reason why many people who have lost weight struggle to keep it off–willpower is no match for brain chemistry–over time, your “will” weakens and you will crave the very foods that cause you to gain weight and feel out of control.
Part 3 of this series will outline a program to help you eliminate these cravings and get back control of your life.
