Two chemicals in the brain that affect our ability to succeed on a diet are dopamine and serotonin. Dopamine affects our ability to control our impulses. If we feel like we have little self-control it may be that our body is not producing enough dopamine. Dopamine is produced by the amino acid “phenylalanine” so it can be increased by eating protein (as protein is made up of amino acids). However, eating protein is not enough. Cardio exercise increases the circulation in our body and allows the phenylalanine to get to the brain. Serotonin affects our mood. If we are ever tempted to eat out of stress or boredom, it may be that our body is not producing enough serotonin. Serotonin is produced by the amino acid “tryptophan” so it can be increased by eating protein (as protein is made up of amino acids).
However, as with phenylalanine, eating protein is not enough. We need to exercise, and specifically work out with weights to allow tryptophan to get to the brain. Why is that? Tryptophan is a weak amino acid. Ordinarily the stronger amino acids travel to the brain first and don’t allow tryptophan to cross the blood-brain barrier. If we work out, the stronger amino acids will become preoccupied re-growing the muscles. Tryptophan, which is not used to regrow muscles, will then have a free pathway to the brain.
If one knows what needs to be done to diet successfully but eats anyway because of stress and boredom, and feels like they have little self-control, it may be that their body is not producing enough of these chemicals. Food plays a big role in producing these chemicals, and because people eat less on a diet, the natural result is that the brain becomes more and more deficient in these chemicals over time. This is one of the reasons why exercise plays a bigger role later on in the diet and on maintenance than in the beginning. Can you name another reason?