That's around 80 grams of carbs. Unless that was your pre or post workout meal then those carbs will not aid in your fat loss goals.
Those potatoes created a massive spike in insulin. The steak you ate was likely high in saturated fats. That insulin mixed with that saturated fat is going stright to your fat cells for storage.
I eat around 12 pounds of sweet potatoes a week, and I'm a little feller compared to the monsters that lurk this board. Sweet potatoes are the best potato imo.