Dopamine depletion
Dr. Varsha Kachroo - consultant endocrinologist, Yatharth Super Speciality Hospital, Noida Extension (India) - said: "When drinking coffee, caffeine stimulates the central nervous system, increasing the levels of certain neurotransmitters, especially dopamine, which helps increase alertness, energy and concentration.
However, this process may decline as the effects of caffeine wear off and the body has to readjust the balance of neurotransmitters."
Sugar content in coffee
“Drinks containing caffeine and added sugar can produce an initial euphoria due to the rapid rise in blood sugar levels, which stimulates the release of dopamine, a chemical associated with feelings of pleasure,” explains Dr. Kachroo. “However, as the body processes and eliminates the sugar, this feeling of pleasure fades, leaving you feeling sluggish and tired, which can lead to sleepiness.”
High calorie ingredients
Dr. Kachroo notes that some coffee drinks may contain other ingredients like milk, chocolate, cream, or sugary syrups, which can make them high in calories. This can lead to a large amount of calories, making you feel full and leading to fatigue and sleepiness.
Adverse effects of caffeine
For some people, caffeine can have the opposite effect. This can happen when their bodies are sleep-deprived or experiencing disrupted sleep patterns, Dr. Kachroo explains. In these cases, caffeine not only fails to help them stay awake, but can actually increase feelings of fatigue and promote the need for sleep.
