After reading Gem's article she wrote about gluten and your gut it reminded me about an observation I have seen in the gym. After my clients or athletes have had a cheat meal where they often consume some form of wheat whether it be pizza, pasta, etc. they often have a decrease in performance. This decrease in performance often shows itself in a lack of strength but the biggest factor I see is in a loss of coordination and muscle control. In this picture below Marcus had consumed his cheat meal 1 day prior to the session.
This image was on the Monday. On the Friday, we performed the same workout. In this Friday workout Marcus performed 12 reps at 30kg and the bar path was much better. You can see this with the alignment of the bar in this next picture.
If you come from the "it fits my calories camp" and you don't care about the quality of food you consume, then you could be leaving a lot of performance gains on the table.
We train for performance.