Nuts and seeds work for me.
But the trick is you have to eat a LOT.
In the US, macadamia nuts come in 7 ounce jars. Eat half a jar one day, eat half a jar the next day. Wait a day, start again.
Also works with peanuts. Eat an 8 ounce jar over 2 days. [yes I know peanuts aren't primal, but IMO the movement is more important.]
Sunflower seeds and pumpkin seeds also work. Make sure it's only the nut meats, not the hard shell. The shells have sharp edges, eek.
Flax seeds are pretty tried and true. 1 teaspoon along with breakfast, lunch, dinner, for two days. Stop for a day or so and start up again.
If someone tries this and it works, let me know.
5'0" female, 44 years old. Started Primal October 31, 2011, at a skinny fat 111.5 lbs. Low weight: 99.5 lb on a fast. Gained back to 115(!) on SAD chocolate, potato chips, and stress. Currently keeping food tracker.
I (try to) follow by-the-book primal as advocated by Mark Sisson, except for whey powder and a bit of cream. I advocate a two-month strict adjustment for newbies. But everybody is different and should tweak Primal to their own needs.