Complex sentence: A foodshake for replacing a meal should include less quick carbohydrates and will usually have a higher level of fat if you are trying to bulk up but less to no fat if you are trying to lose weight.
Split into simpler sentences: A foodshake for replacing a meal should include less quick carbohydrates. Meal replacement shakes should have a higher level of fat if one is trying to bulk up, and less to no fat if one is trying to lose weight.