Is what you are doing now working? Are you happy with the rate at which you losing weight? Is it a reasonable rate--not to fast and not too slow? Are you having problems with hunger? Do you have cravings that are really hard to resist?
If what you are doing is working, you're happy with your weight loss, and you aren't having problems with hunger or cravings, then I'd say don't change anything. If the diet you are on now is working both physically and emotionally, then I always think it's best to stick with it until it stops working. That way, you've got a alternative in your back pocket that you can go to if you plateau or start having problems with hunger, etc.
On the other hand, when my weight loss stalls or I'm having a lot of problems with hunger/cravings, that's a clue to me that I need to change something in my diet. So if you are having problems like this, why not give your nutritionist's advice a try and see if it helps. If it doesn't, you can always go back.
I don't believe that a calorie is a calorie--I think there's a big difference between eating a 100-calorie pack of refined carbs, 100 calories of fruit or veggies, 100 calories of yogurt, 100 calories of chicken, and 100 calories of nuts. But I also don't bother with a low carb diet. Carbs have been an important part of my diet for the entire time I've been losing weight and have always been at least 50% of my calorie intake, if not more. Right now, I average around 50% carbs, 35% protein, and 15% fat. I'd like my calories to be a little higher in fat and a little lower carbs, but I'm not so concerned about it that I've made any significant progress in achieving that. Also, most my carbs are either whole grains or fruits and veggies. No white rice, white bread, or white potatoes for me. Also, I try to keep added sugar to a minimum. I lost 35 lbs, got to my goal weight on this diet, and have maintained for two years on this plan.
That said, I also think it depends on how ambitious your goals are. I do think I might be able to lose a little more weight if I went to a low carb diet, but I
my carbs. I'm happy enough with what I weigh now that I don't care to give them up to be a little thinner. But if you are still able to lose on your current diet, you can always wait until you get to the point where you aren't losing to decide if you want to try to go lower by reducing carbs.