You wouldn't fill your fuel tank with Swamp Water, would you?
If anyone knows me, they know I LOVE analogies. Proper Nutrition and Exercise is equivalent to what High Octane and Quality Fuel is to Vehicles and Racing. If you put in Low Octane contaminated garbage Fuel in your Fuel Tank, or even Piss in your Fuel Tank, and/or drive around on little to no Fuel, don't expect your Vehicle to run great and be dependable. The same goes for our Body and Mind. What we eat, drink, think, and do repeatedly directly affects how our Body and Mind functions. Be smart and take proper care of yourself by feeding your Mind and Body with the best Fuel you can find and afford.