It's a time bomb - eating sugar and processed food!
If you eat processed food (too much), a lot of sugar, bad fat, ... in the end you have to pay for it.
Don't wait as long (as I did) to find out that eating healthy, gluten free (in particular Paleo), gives your body and mind a chance to stay in shape, having all the energy for a good and energetic day, without going through peaks of tiredness and concentration or, worse, developing diabetes, obesity, ...you know the deal.
In my experience eating Paleo is a simple way to cleanse, recover your body's health & energy- At least, that's what happened to me AND many dear friends. (I Built up a group of successful healthy eaters aka Paleo-Buddies)
Now, a solid start I often recommend (I get asked all the time) is the Paleo Plan on Tim's blog (for your reference timreviews.com/paleo-recipe)
Otherwise, there are some good books on Paleo on Amazon.