If your thyroid hormone is in the normal range, I would not want to increase it during a bulking phase. Increased thyroid will speed your metabolism and burn some of the calories that would be stored as fat, but it will also have an effect on how well you will be able to gain muscle. Your best option is to maintain a diet that is rich in protein, at least 1g per lb of muscle mass, and then play ith the fats and carbs to find a balance, eating enough to grow, while not storing a lot of additiona body fat. Then after the cycle is over and you have recovered, if fat loss is your next goal, that would be a great time to focus more on fat loss, while still keeping protein high, and once again, alter carbs and fat to reach your new goals. 

If you find yourself getting a little overly fat in this bulking phase, consider adding in some LISS cardio at the end of your workouts. If this is not enough to stay on the leaner side while bulking, the diet needs to be adjusted. 

One last tip. While "bulking", many guys use compounds that will make your body hold additional water. This water can be of benefit, making you stronger and hydrating your muscle. But some of this water can go to sub Q areas of the body, like around the mid section. The key is knowing  whats water and whats fat. So just becuase you see your abs blur in the first several weeks of a cycle like Sust/EQ/Drol, does not mean you gained a ton of fat. Some of it may be water and will go away after the cycle has ended

For anyone interested in working with me, one on one, I build individual diet, gear and training plans for your needs. We work together on a plan you can follow, desinged around your life and each week, we adjust the plan to help you continue reaching your goals. I work with everything from competitive physique athletes to normal men and women, that just want to be in great shape. Come over to the Next Level Nutrition page for more details, and contact me today!