Over the years on lowcarb forums various “wonder foods” often come up and get tossed around as weight loss aids. Macadamia nut oil, coconut oil, avocadoes, avocado oil, walnut oil, flaxseed, flaxseed oil, have all at times been popular.
You might want to put into your thinking about all this that I know of no one who got to, or anywhere near, goal who has found that macadamia nut oil (or ANY particular kind of oil or any other single food or product) was in any way crucial or even very helpful to their success.
If something somewhere along the journey is preventing you from losing, it’s usually not something you’re NOT eating that you need to add. It’s usually something that you ARE eating that you need to either cut way back on or in some cases entirely avoid.