It’s a somewhat contentious issue, but most would agree that to maximise fat loss, you want to exercise when your blood sugar levels are low, so that you tap into your fat stores for energy.
This is the reason for training first thing in the morning on an empty stomach. Your blood sugar levels will also be low post workout, as they will have been burnt as energy to lift the weights, so again, you tap into your fat reserves for energy. This also leaves you more energy for the weights workout…