If you’re trying to lose weight and tone up, it’s no secret that getting enough protein is important. Protein satisfies your hunger and helps you build muscle, which in turn helps you burn more calories. But before you go reaching for a protein smoothie, make sure you know what’s in it. Many store-bought smoothies are full of sugar and calories, so you’re better of making a protein drink at home.

Now… which protein to choose? There’s no shortage of sources — rice, soy, whey… the list goes on. So what type is the “best” of them all?

Many top experts have an answer for you: rBGH-Free Whey Protein Isolate. This type of protein is sourced from milk, and has more protein per serving than most of the vegan varieties like rice, soy, and pea protein (but those are all excellent options for vegans). It’s also growth hormone-free (that’s the rBGH part).

Look for a pure formula with as few as possible ingredients — more than 5 or 6 is usually sign that there’s stuff in there you don’t want or need. Also ensure you pick a low-sugar or Stevia-sweetened powder. Here are two we’ve tried, tested, and love, plus a recipe:

Jackie Warner Whey Isolate Protein Powder – Vanilla Bean

Beveri rBGH-Free Whey Protein – Natural Vanilla Flavor

Easy Blender Smoothie:

1/2 cup Blue Diamond Unsweetened Vanilla Almond Milk
1 handful of fresh kale
1/2 banana
3 ice cubes
1/2 scoop of protein powder

Pour the milk in first, then sprinkle the kale on top and blend (thick, leafy greens are packed with nutrition, but can be hell on a blender without enough liquid!). Next, add the banana and protein and blend again. Finally, add the ice cubes and blend once more (just to thicken the shake and make it colder — yum).