Advice needed

Amazon74

Hi everyone,
This is my first post so please be gentle with me!
Like many others I've just started on a fitness regime this year, previously I was a bit rum lazy.. Resulting in me putting on weight... Having taken the bull by the horns I've also decided I'm going to run a half marathon so I'm training for that too at the moment (never one to do things by halves!) . In addition to this I have also hired a personal trainer, as I have a tendency to be a bit lazy at times.


This regime started about three weeks ago and I'm seeing massive benefits already, and I haven't even weighed myself yet!
Anyway the reason for this post is that I had a bit of a disagreement with my trainer today and I keep turning it over in my mind.. I've been tracking what I eat on myfitnesspal and its a bit of an eye opener so to speak!

Checking my diary I have been averaging about 1900 calories a day. To give a bit of background I'm 5ft 9 and presently working out 5 or 6 days a week, i do weights and running. Last week I averaged around 13 miles during the course of the week, so based on how unfit I am I thought that was pretty good going. today my trainer said I should be looking to consume about 1600 calls a day. Now I'm no expert but on checking this, I see my BMR is 1595.. And that's even when I'm not doing anything. So we've had a heated discussion on the number of calories I need to reduce too to see a difference.
Which of us is right? For background, my eating habits were not good at all prior to starting this - I had no energy at all, couldn't get out of bed, let alone run.. So I've been concentrating on eating healthy nutritious meals with fruit/yoghurt for snacks..
I think I need some reassurance really as now I'm concerned I may be eating too much and won't have lost any weight !