Strength Training doesnt record calories burned??

1) Logging under the strength training section doesn't record calories burned because it is nearly impossible for the number to be accurate. Too many variables (number of sets, reps, weights, effort, rest periods, etc). If you are looking for the calorie counts you can log Strength Training under the Cardio section and it will give you a number. I wouldn't necessarily trust that number as being accurate for the reasons listed above ^^.

2) Did you just start working with a trainer? It's pretty common for weight loss to stall temporarily when you first start a new routine. It may take a few weeks. You also mention that prior to MFP you were only taking in 800-1000 calories which is really quite low and not sustainable in the long term. It's only been one week, I wouldn't worry about not losing anything in the first week.

Your diary isn't open and you haven't given any details about your routine or diet so no one is really going to be able to answer "Why did I gain" for you.

Check out this link for a good starting point on using MFP successfully:
http://community.myfitnesspal.com/en/discussion/1080242/a-guide-to-get-you-started-on-your-path-to-sexypants

Apart from the info in that thread itself, it includes a plethora of useful links to other MFP threads that you should check out.

3)800-1000 calories is not sustainable or healthy in the long term and MFP is designed to help people lose weight in a healthy manner. It will not encourage you to eat too few calories. You can still track them if you have low calorie days, it just won't let you "complete" the entry which doesn't really do anything besides make a post on your wall and give you a guesstimate on what you'll weigh in 5 weeks.

Try to get the calories in to the amount that MFP tells you, but don't stress over it if you can't manage it every single day. I think you'll find that the longer you are working with a trainer and doing dedicated strength training, the more of an appetite you will develop.

I took a look through the past week or so in your diary and noticed that your protein numbers are on the low side. Personally, I find it easier to eat enough calories when I am focused on reaching my protein goal. As a result of focusing on protein, my carbs tend to be a bit lower than they would otherwise. I find when I eat a lot of carb-heavy food I tend to feel full even if I haven't come close to meeting calories or protein/fat goals. Everybody is different though so the real take-away is to just stick with it (seems like you've got a pretty good start on it!) and find what works best for you.

Best of luck!

I found it a bit discouraging to only use a scale to measure loss with strength training. Seeing that it took 2 months to lose five pounds and then I noticed I was slimming down. Try taking body measurements as well since fat percentage loss isn't really registered on scales or use a calipers or a similar device. Nice to see that I've lost 6" off my waist though.