If I snack on cheese during the day I won't include it in my meals and vice versa. Cheese snacks during the day usually consist of a small triangle of smoked Gouda in the morning and a couple string cheese sticks in the mid and late afternoon. For a meal, I'll use two or three slices of American or cheddar with my meal.
I've found that cheese really fills me up and a perfectly adequate breakfast to keep me going until 2:00 PM is an ounce or two of cheese and 10 or 15 smoked almonds.
Regarding diet soda, I haven't had caffeine or aspartame for about five months and haven't had a single migraine during that time. Check out Waist Watchers caffeine free diet beverages with Splendra:
http://www.adirondackbeverages.com/ad-ww.html
I drink the stuff like water! I'll usually drink around 32 ounces of various caffeine free Waist Watchers flavors in addition to the 100 to 120 ounces of water I drink each day. Remember that caffeine is a diuretic and "doesn't count" towards water intake. Most diets state that you should drink an ounce of water in addition to every ounce of caffeinated beverage you consume.
Now, for the Atkins secret dessert: Sugar Free Jello! The generic stuff is ultra cheap and contains zero carbs. I make the Jello by dumping in a cup of boiling water, stirring until mixed, then mixing in a cup of the Waist Watchers Ginger Ale or Citrus Frost! Best carb free dessert ever!