The suggested portions are a great starting point, but as you begin to eat these whole, nourishing foods, your body will give you plenty of biofeedback, like "I'm still hungry!" or, "I'm full!" Simple but effective :)
Your intake needs can change based on your daily exercise or how much you're moving, so listen to your body. If you're not hungry for all the food, don't force yourself to eat it. If you're still hungry, increase your serving size, and know it may change day to day.
I highly encourage you to go through a day or two as it's prescribed, and then adjust accordingly. Don't be afraid to combine meals/snacks if you don't need to eat so frequently, or increase portions if you're finding you're still hungry after each meal or at night.