increasing calories

Hey Tanya--it's been great to see your questions and posts on the forums. Way to throw yourself into things! Have you started marathon training yet? Keep up your logs ... I've found people give me really good advice when they can see what I've been doing.

Yeah, 1400 cal was way too low for being in training. And yes, you will get a serious appetite surge as you increase the calories--(slowly helps to not have the surges be as bad)--the body has a very effective mechanism that kicks in when it's been underfed and then gets more: it's called hunger. It's like your body is saying, OMG we have food now--let's eat all of it we can!

Yes, you will be okay, and what you're going through is normal. Eat whole, filling foods ... follow your nutritionist's advice.

Good luck! Hang in there!

Fatter on lower calories = not just possible, but likely.

When you don't eat enough and work out, your body goes into starvation mode. It will use every calorie much more efficiently (I call it 'hoarding' calories) and your metabolism slows to a crawl, thereby conserving even more energy (e.g., keeping/gaining weight).

Eating appropriately normalizes your body's response to food.

This is exactly the method I used when I lost 20 lbs a couple years ago.  Well, the only difference was I divided my calories into just 3 meals/day.  That just works much better for me than smaller meals more frequently.  Otherwise the method of using BMR as a base and THEN adding in for workouts worked very well for me.

1400 calories/day is not all that low on rest days depending.  My BMR is around 1900 cal/day so 1400 cal/day was my base diet during my weightloss (500 cal/day deficit).  All of this was before I even thought about doing tris so my basic exercise was to walk 4 miles on 6 days of the week.  That is around 300 calories to add back into my diet on those days so around 1700 calories/day.  On days when I did not exercise, I stuck with the 1400 calories.

Good luck with your new nutrition plan.  A lot of this is trial and error and lots of analyzing this and that.   I have confidence that if you keep working at it, you will find a way to achieve your goals.  Go for it!