Here's how I make my protein shakes palatable... I think it's around 6 carbs and roughly 500 calories (30 g fat, 28 g protein)

3 ice cubes
2 tablespoons soya protein powder (vanilla or chocolate)
1/4 cup ice cold water
1/4 cup cream (usually 18%, 35% thickens up too much if you blend for long)
1/4 cup whole yogurt (I use the Libery plain which has 10% mf)
1/4 cup whole cottage cheese or ricotta
1-2 tbsp Splenda
1 tsp vanilla

Blend away for a long time. It's much better, though very "dairy". The cottage cheese isn't completely necessary, just make sure you substitute more water. In summer I'll often add some fresh blueberries or strawberries (1/4 cup).

Good luck!

Lisa