I am suffering from brain fog since a long time. As the temperature of the day increases, my brain becomes foggy. I find it difficult to concentrate and focus. It starts at around 9-10 am. Somewhere between 1-3 pm, it's most intense and around 5 pm, gradually the fog begins to fade. I have tried meditation also, I experience mental clarity only for sometime. It was like the fog was delayed by a few minutes or hours. I am tired most of the times. Not sure if it is diet related or a result of brain fog. I am underweight and weight gain has been a challenge. I have researched the web and it appears brain fog is still not a defined medical condition.