Eat a sweet potato during your workout and have a coconut milk/protein shake before bed. See how you respond.
On the other hand, I don't think 5-3-1 as prescribed is a particularly good choice if you're trying to do a high intensity, caloric surplus plan. The program moderates intensity for long term gains. If you're spiking your caloric intake with the intention of quick gains, you should probably go with a higher intensity program.