Avoid fatty meals on days when you plan on taking Viagra. This can cause Viagra to take effect more slowly. Try eating light meals throughout the day before taking Viagra, and avoid heavy meals with red meat, fried food and other high-fat components. Also pay attention to the possible risks when taking Energy Drinks and Viagra. There might also be food-drug interactions with Viagra. For example, grapefruit can elevate blood levels, making it a natural alternative for treating ED. However, it with Viagra could lead to some side effects like headaches, flushing, or low mixing blood pressure.