Hi Trish! I've been following the Extreme Fat Smash menu plans, but I'm guessing the ambiguity with portion size is the same...
I would guess the guidelines are for no-more-than rather than required amounts per day.
Instant oatmeal and brown rice are stripped of some of their fiber in order to make them cook more quickly, so they aren't as good for you as rolled oats, steel cut oats, and regular brown rice. What I like to do is make steel cut oats in the crock pot. It takes about eight hours, so I do it overnight and it's ready for me in the morning. I use 4 cups of water plus 0.5 cup of either skim milk or fat free half and half to 1 cup of steel cut oats. Then I usually throw in about a cup of dried fruit (crasins, cherries, raisins, apples, etc.). Sprinkle on some cinnamon and splash in a little vanilla extract and set that puppy on low.

For brown rice, I cook up a couple servings at a time and then refrigerate what's left over so I can heat it up quickly in the microwave for the next bunch of meals. I really prefer the taste of brown rice over white.
Plain yogurt doesn't have any added sugar. I like to mix mine with about a half cup of frozen blueberries, some cinnamon, a splash of vanilla, and either some sugar-free coffee syrup (hazelnut or caramel are really good) or a squirt of agave nectar.
Hope that helps!
Kara