You could attempt to do both but the process would be a slow harsh one.
There is different diets for bulking and cutting.
During bulking you want a high carb diet because while weightlifing you burn up muscle glycogen very quickly and if you fail to replace it every day by eating high carbohydrate foods, your glycogen stores quickly diminish. Within about three days of a severe carbohydrate cutback, your muscle glycogen will be almost totally depleted.
Glycogen is your primary energy source for weight training and high-intensity
exercise, so this explains why your energy will be low and your workouts will suffer when you don’t eat many carbohydrates.
While cutting most bodybuilders go on a low carb diet. If they did not do this they would not be able to reach the 3-5% bf range. Now you ask why do they go on low carb if they may affect possible gains? Well here are some advantages and disadvantages:
Advantages:
-Reduced carbohydrate, high protein diets are highly thermic,
-Reducing carbohydrates and increasing protein controls insulin,
-Reducing carbohydrates decreases glycogen forcing your body to use more fat for fuel,
-Reducing carbohydrates and increasing protein reduces water retention, giving you sharper, more detailed muscle definition.
Disadvantages:
-Very low carbohydrate diets are difficult to stay on,
-Weight/fat re-gain is almost inevitable,
-Very low carbohydrate diets can be unbalanced and lacking in essential
nutrients,
-Very low carbohydrate diets may be unhealthy,
-Very low carbohydrate diets can cause your energy levels to crash,
-The weight loss on a very low carbohydrate diet can be deceiving ( most is lost from water and muscle)
-Low carbohydrate levels affect your mood and mental state,
-Low carbohydrate diets may cause muscle loss - why? When glycogen stores are severely depleted through dietary restriction, your body can also burn protein for energy, converting muscle tissue into glucose through a process
called gluconeogenesis.
Any questions?