Nope. I didn't buy slaves. But I did breed my 2 starters, and was able to capture 2 invaders that I breed as well. Then I got 1 rando that wanted to fight for me, and 2 missionaries that wanted to purify my harem. I breed the Missionaries but not the fighter. Because he was the only male that showed up. It was close, but I still had about 5 food left when I finally built my Trading Post
to be fair, you cannot buy anyone without a trading post - barring any random events that might happen.
i captured 5 invaders and took in 2 wandering randos from events, and i ran out roughly a week before i could get either tech required.
we really need to have food expeditions back as a stopgap until the time the expedition map is actually implemented.