The half-hour after you workout is a very important time to eat a meal. This "nutritional window" is a time when the body is looking for nutrients to recover from the previous workout. Also, if the workout was fairly vigorous (which most Hubbard Training Systems' training sessions are) your metabolism will be elevated, which will allow you to ingest a good size meal without worrying it will be stored as fat.
Glycogen, which is the carbohydrate stored in your muscles and liver, provides a significant amount of energy while you workout. The longer duration and/or more intense the workout, the more glycogen you will use. The enzymes that synthesis (restore) your glycogen are at their highest activity levels immediately after your workout. Now, if you plan on training hard regularly, you need to replenish your glycogen or you will notice that you don't recover well, feel weaker, and have more muscle soreness. So, during the "nutritional window" try to get 30-80 grams (depending on your body size) of carbohydrates to restore your glycogen. This may be equal to one bagel (or 2/3 of a cinnamon crunch Panera bagel). Also, this is a good time to ingest your sugars that you crave. Don't worry about sugars spiking your blood sugar here. The muscle cells are primed to take-up sugar (glucose) to replenish glycogen and insulin levels are low because of your exercise. This means the increase in blood sugar will not be converted to bodyfat.
The muscle rebuilding process, known as protein synthesis, is also at its highest rate immediately after a workout. It makes sense to eat some protein during the "nutritional window" to help your muslces recover and grow. Aim for 20-30 grams (again, depending on body size) of protein to give your muscles all of the amino acids (protein building blocks) they need to recover. Fat will slow the digestion process, so try to eat lean, quick digesting sources of protein such as skim milk, yogurt, chicken breast, protein powder, or low-fat cottage cheese.
If you want to maximize your efforts to get stronger, build muscle, and shed body fat, then you must take advantage of the "nutritional window," the first 30 minutes after your workout. Changing your body composition starts with consistent and progressive training, but also must be supported by sound nutrition practices.