For the smaller people too.
Get yourself a new dietitian, but besides her snarky comments, and lack of faith in you, the advice may be the same, and you should give it a try, if what you are doing is not working. I would guess that is why you went to a dietitian in the first place, so whatever the advice you get at the new dietitian's, at least give it a try.
As far as losing weight on a caloric deficit, it will continue. You lose weight if you don't eat enough. I read a book about conscientious objectors in WW2, who volunteered to undergo starvation, as a means to learn better how to feed them properly to get them back to good health. This was a worry as half of Europe was starving due to the war.
These volunteers lost weight steadily, and a slow metabolism did not stop them from losing. I myself have lost over 100 lbs in a summer by starving myself, and the idea that low calories will slow down your metabolism enough to stop weight loss is a complete myth. People use it to justify why they aren't losing, because they can't figure out why they aren't losing. Usually it is a medical reason, or they are not counting calorie intake, or expenditure correctly, or even just forgetting something they ate.
Where this lower metabolism comes in, is that when you START eating again at regular levels, you regain faster. If 1800 was your base before starvation, and it is now 1600 due to reduced metabolism, you can eat 2100 a day, and gain 1/2 a lb a week on 200 less calories than you were eating beforehand.
Starvation mode is the body's defense against starvation. It primes you to gain the weight back more quickly. However, it doesn't happen during starvation. It may slow down your weight loss some, but it won't lower your metabolism to 500 calories a day. At that rate, you will lose weight consistently.
This is not a suggestion that you do so, just had to respond to your question. Of course you will lose weight if you eat less calories. People don't get fat from eating too little, and lose weight by upping calories. They do the opposite. People have grasped onto ideas, and sadly are so confused that they think bananas or eggs are unhealthy, and if they ate more, they would be skinnier/healthier.
I am 211 lbs and eat about 2100 calories, so even 1400 calories is probably too low for you, but that is for you to work out with your dietitian, and doctor. I would be willing to wager that people who say they eat 1200 calories a day, eat a lot more, and just don't count it.
Get the new dietitian, set a range for eating the proper calories/nutrition, and give it a try, see what happens. Don't cheat, and you will most likely see results, then all you need to do is repeat. If in between visits, you find you don't like certain foods, or how they make you feel, tell your dietitian. Never " just do it ", so you can lose weight. In theory, you will be eating this way for life, so make sure all the food you are eating is food you like. Of course, you will have to give the foods a fair shake, and some that you don't love today, may be a favorite in a month, but your dietitian can only help you if you work with them. If you cheat, count it, if you have a problem, tell them. The better the information, the more your dietitian can help you.
Russell - current BMI 28.6
197 - bmi 30 - done
164 - bmi-25
| current weight: 183.4