Sugar

my dietitian wanted protein shakes to have less than half the number of carbs as protein grams. In other words for a shake with 30 grams of protein there should be no more than 15 grams of carbs.

Here is the suggested limits by my dietician for protein shakes (both pwdered and ready to drink)

Calories:   100 - 180
Protein:   20 - 40
Carbs:   5 - 15
Sugar:   0 - 10
Fat:   0 - 5

I use the Premier Protein shakes very low sugar and a lot of protein. Get them at Costco best price I have found. 

 You have the wrong shakes.

Seek "low sugar, low carb" protein powders or shakes instead.

My max was 12 grams per meal.

However, I was lucky to get 5-8 grams without dumping. I can eat 12 grams now but barely, and not on an empty stomach or otherwise concentrated. So, a glass of orange juice that equals 12 grams of sugar is a no... but a cinnamon apple sauce on my pork chops with 12g of sugar is fine.

And 20g of sugar with only 15g of carbs really sounds low quality to me. I use BSN Lean Dessert which is whey concentrate/isolate blend with 8g of carbs (2g from sugar)and 21g of protein per scoop.

I am on 2 weeks pre-op liquid diet and had to buy the shakes from my doctor office. It's Opitfast and it also has 20 Grams of sugar per serving, and 14 grams of protein and I am suppose to have 5 servings a day. It seemed high to me also ... but that's what they have me drinking.

Good luck