Food can mean different things to different people. For some, it is simply a necessity and a means of adding fuel to their body to keep them going. For others food maybe something that they really look forward to. They look forward to their next meal and are planning what they are going to have for the remainder of the day. How ever you see food, it is important to ensure that you are getting the right sorts of food when you should be. If you find that certain foods or types of food leave you feeling sluggish then you may have an intolerance to them. Foods that contain gluten often cause many people to react.
If you are not sure exactly what you are eating then try and keep a food for a week or so. Write down everything that you eat and drink then at the end of the week you can look back and see if you have been getting enough of the quality nutrients you need. If you notice you are lacking in one particular food group then see what foods you could incorporate to try and increase your intake of those and see if that makes you feel any better.