You need to focus your hIGH GI carb intake in your during and mainly PWO window and concentrate on lower GI sustained release sources the rest of the day.
In other words really spiking your insulin only at the times it is of benefit to you. In the PWO window in order to flood the muscles that are screaming for nutrients and glycogen and aminos for recovery growth and to halt catabolism.
Then the rest of the day concentrate on slower sources, fruit, veggies, oats to a certain extent. get in your good fats and solid protein sources. All these leading to a lower and more consistant level of insulin reaction.
All in all yes a food is not a food and can have an effect on your BF/LBM gain but if your choice of food are solid then your BF gains are more due to intake being to far above the level of use. While bulking you need excess their is a fine line between excess and EXCESS. You simply have to find what works for you. Experiment, document and LEARN.