It's basically no carbs, but you Can only eat food that is either speed or protein, so for instance, you can't have baked beans or muller yogurts .
You also get 2 heb. An example of my day would be
Breakfast -big bowl of fruit, or eggs with chopped broccoli and ham.
Lunch-meat with salad
Dinner -meat with lots of veg.
Snacks - fruit and synned items like chocolates.
Heb -2 HiFi bars. (You could have 4, but 1 is speed as a heb option)
To be honest though, just cutting carbs out for the day would probably increase a loss I'd imagine.