The connection between these three is an amazing one. Sex or being in love is a natural desire which provides pleasure through releasing many chemicals in our body. Chocolate somewhat manages to do the same and for that reason we hear statements such as chocolate is better than sex. There are an awful lot of similarities of chemical processes between the two, which causes the comparison between love and Chocolate. Both evoke similar reaction from a human brain as the Chemistry behind them is equivalent. So when people say that Chocolate is better than Sex what they mean is that they are not getting any sex so they have to do with the chocolate for providing them with matching pleasure.
Our brain is a very complicated processor and we will take a long time to fully understand and appreciate the complexity of its progressions. It is the main point in our body which receives all the signals from the body and then reacts in order to respond to all those signals. These signals are carried to the brain through cells such as neurons. Between these neurons, there is a synaptic cleft which allows passing of the message across through neurotransmitter such as acetyholine, Amino acids and Monoamines such as noradrenaline, dopamine and serotonin.
These neurotransmitters are responsible for ensuring that signal passed from one neuron to another neuron is extremely fast. For example if any part of our body is touched, that stimulates the sensory nerve cells to carry information to the brain. If the touch is harmful, the brain will respond by moving that part of the body to avoid any harm. The presence of certain neurotransmitter will cause the signal to travel to brain very fast. If there is anything in synaptic cleft that is blocking the neurotransmitter, the information will be passed across slowly and therefore the signal to, and the response of brain will also be slower.
Therefore whenever there is any activity in the body, whether it is having sex, falling in love or consuming chemicals such as drugs or Chocolates, it is the role of these neurotransmitters that provides our brains with the information and creates pleasure.
When we are in love, our body releases many hormones which stimulate the production of chemicals such as these neurotransmitters and boost pleasure points in our brain. The neurotransmitters known to be responsible for these pleasure points are endorphins and phenylethylamine which together causes the release of chemicals such as dopamine and serotonin. These chemicals are also known to be present in drugs such as amphetamines and cause hallucinogenic effect in the body, somewhat similar effect to when we fall in love. These chemical are also present in Chocolates therefore presenting the same chemical processes taking place when in love, or when taking drugs. Being in love and eating chocolate, both give you a feeling of stimulations due to release of these chemicals. For that reason many compare, eating chocolate to having sex because both actually follow the same chemical pathway to provide us with exciting high feelings that nothing else compares to.