Well I believe the plan is to get magic and alchemy, and in more of a physical way than just the "wave your arms to fireball". Drinking seer drought to increase your chance of a mood, or eat something to become resistant to poison or heat, and work in an industry that require such resistance, possibly.
I guess the main thing you'd need to do with the more "basic" foods is sacrifice something that won't matter in the first year or two of your fortress, but will when migrants start coming in. Maybe your first few guys, hardened expeditioners, might be more tolerant of such things, but migrants would expect more civilization? Beyond your first seven getting some sort of bonuses to survival type things, maybe poor food could impair developing friendships? If dwarven friendships are important, and you assume that the first seven have all they need for the time being, developing new ones won't matter until you have more migrants than origionals.
Or, how about spices? If foods need to be made of several ingredients to produce happyness, spices could be an easily packed way to increase variety for a while, rather than pack five years of whole meals. They'd likely be expensive, but maybe since it would be seen as a necessity, there could be a discount on it for the first year or two of the fortress. It'd also start running dry a lot faster if you suddenly acquire twenty migrants, now all of a sudden getting four-ingredient food for everyone is a big deal, since the spices ran out four times faster than you'd been counting on.
For that matter, flavorings for booze? The alcohol for beer is barley, but the flavor comes from hops. Ale has a wider variety of flavorings. "Toss fermentable thing in pot" might be enough to get away from needing water, but proper booze takes more than that. Taking with a few units of lightweight hops can jumpstart your decent-beer industry, but that rapidly runs out if you don't get around to farming hops... of course, happiness-producing hops takes second seat compared to harvests that are required for your dwarves to not die.