People who don’t eat meat are especially vulnerable to neurotransmitter imbalances because of the absence of meat protein, which provides all of the essential amino acids human bodies need. Neurotransmitters are chemical messengers that regulate many of our functions, including physical, cognitive, and mental performance, as well as our sleep cycle, weight, and emotional states. Meat protein provides all of the essential amino acids human bodies need. People who don’t eat meat are especially vulnerable to neurotransmitter imbalances, which can result in problems like depression, anxiety, and hyperactivity.