I don't think "balance" is meant to be so much a mathematical thing as a question of eating appropriate portion sizes of all four types of foods at each meal, according to your metabolic needs. 33/33/33% might be mathematically balanced, but it's actually pretty close to low-fat (which is considered 30% of calories or less from fat) and is probably too high on protein.
You need to start off with determining the *minimum* amount of protein you should be eating, which SPII states should be *at least* 1-1.25g per kilogram of body weight. Since you weigh 156, or 70kg, you should be eating at least 70-85g of protein a day, or about 10-12 oz if you want to calculate it that way. Spread that out over all meals and snacks, with a little more protein at meals and a little less at snacks (see the guidelines on SPII p. 232 for specifics).
Once you've got your protein needs squared away, determine your carb needs according to your metabolic type, which based on what you say above is probably insulin-sensitive with burnt-out-adrenals, and the number of meals you eat a day. For example, I'm in the early stages of the IS/BOAG healing program, so I'm eating three meals of 20-25g carbs with two snacks of 20g, for a total of 100-115g of carbs from fruit/starchy veggies/legumes/whole grains. (Also remember that on SPII you don't deduct fiber as on Atkins, so this is 100-115g TOTAL carbs, not net.) Next, add a serving of non-starchy veggies to each meal, for a total of at least five a day; these aren't counted in those carb totals, but will probably add another 25-50g total carbs.
So that only leaves fat, and you're not supposed to count/measure/restrict that except as your appetite dictates (unless you're on a lower-sat-fat plan). You don't go out of your way to get the fats really high as with Atkins, but you shouldn't be deliberately trying to hold them super-low either. These really pretty much take care of themselves if you're following all the other eating rules, such as not eating fats without proteins, avoiding damaged fats, limiting your processed meat and cheese intake. I use a little bit of added fat when cooking meat, put a teaspoon of butter or olive oil on my veggies, and then get the rest from whatever's in my protein/carb foods, and it seems to work fine.
Based on the percentages you listed above, your fat sounds too low, and either your other nutrients are too high or you're just plain not eating enough. Remember, you're not supposed to be eating low-fat or low-calorie, because you can't heal your metabolism that way. My daily intake is roughly 1800 calories, 100g (50%) fat, 125-150g total carbs (85-100 net) (25%) and 100-120g protein (25%). I feel like I'm eating pretty close to her definition of "balance" -- maybe a touch heavy on the protein, but I feel good about the rest of it -- and you can check my journal for menus and specifics if you like. You might think about posting your own menus in a journal as well, since the overall composition of your meals and snacks is more important than the Fitday percentages.
Consume the minimum levels of recommended protein, hit your per-meal carb targets, eat non-starchy veggies at every meal, and don't stress out one way or the other about fat consumption, and don't worry so much about the numbers. Also, try going back and rereading Chapter 11 -- it took me going through it about 10 times to "get" it, and planning out my menus for the first week or so felt like working calculus problems
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