What happens in your brain and body when you have a soft drink? Several rather undesirable things. As the sugar from the soda or sugary drink is absorbed into your blood stream, your brain’s hypothalamus sends a message to your pancreas, telling it to secrete insulin to deal with the higher level of blood sugar. The insulin now instructs your fat cells to pull the excess glucose out of your bloodstream and store it for future use. The problem is that you likely won’t be pulling the stored glucose out of those fat cells any time in the near future because you keep drinking sodas or sugary drinks or you keep eating refined foods, which packs even more into those fat cells—and you continue to gain weight, a little bit at a time. In addition, you are less likely to drink water, which can dehydrate the brain and interfere with its effective functioning. The brain is largely composed of fluid and needs water, a nutrient, in order to function efficiently.