Why am I gaining weight?

Are you working out as well? If you're working out, then that means you're gaining muscle. Muscle weighs more than fat. Don't freak out! Weight is simply relative. Weight is not a very accurate measure of your success either. You must re-train your brain to think differently.

I joined MyFitnessPal about 2 weeks ago and since then I've been counting calories on it. I've been putting in absolutely everything I eat each day, and I've been avoiding unhealthy stuff, and eating loads of fruit and veg. I've cut down on bread as well. They set my maximum as 1320 cals per day and minumum 1200. I've managed to stay within those boundaries pretty much the whole time, except for one or two days where I was about 50 cals above or below the limits.

Do you own a food scale and do you use it regularly?
Do you use measuring devices?

I know you can gain weight if you eat too little

You don't gain weight from eating too little. Your body cannot manufacture matter out of nothing.

But since I joined I've gained 4 pounds! How is that possible? I've been trying to eat as well as I can, with a balance of foods, but it hasn't worked. My goal is 9st 12, and when I started I was 10st 4, not I'm 10st 8! I've been weighing myself every morning just before I get in the shower, so clothes, food and drink won't affect it. Can anybody enlighten me as to what went wrong?

1) You could be eating more than you think.
2) You could be retaining fluids.
3) A combination of the above.

You are not gaining muscle at an appreciate rate on that calorie intake.

I joined MyFitnessPal about 2 weeks ago and since then I've been counting calories on it. I've been putting in absolutely everything I eat each day, and I've been avoiding unhealthy stuff, and eating loads of fruit and veg. I've cut down on bread as well. They set my maximum as 1320 cals per day and minumum 1200. I've managed to stay within those boundaries pretty much the whole time, except for one or two days where I was about 50 cals above or below the limits.

Do you own a food scale and do you use it regularly?
Do you use measuring devices?

I know you can gain weight if you eat too little

You don't gain weight from eating too little. Your body cannot manufacture matter out of nothing.

But since I joined I've gained 4 pounds! How is that possible? I've been trying to eat as well as I can, with a balance of foods, but it hasn't worked. My goal is 9st 12, and when I started I was 10st 4, not I'm 10st 8! I've been weighing myself every morning just before I get in the shower, so clothes, food and drink won't affect it. Can anybody enlighten me as to what went wrong?

1) You could be eating more than you think.
2) You could be retaining fluids.
3) A combination of the above.

You are not gaining muscle at an appreciate rate on that calorie intake.

This is everything I was going to say. Perfect

If you're eating in a calorie deficit, even on the off chance that you are gaining a slight amount of muscle, your weight gain is not muscle. You are not going to increase in total mass eating at a deficit, and that goes for both fat gain and LBM gain.

Could you gain muscle? Under the right conditions, even in a deficit, you could gain a small amount but I assure you, you didn't make a 4lb gain in LBM in 2 weeks on 1200 calories.

It's very, very likely to be fluid retention.

I know you can gain weight if you eat too little

You don't gain weight from eating too little. Your body cannot manufacture matter out of nothing.

That is tremendously wrong. For the last several years I have been gaining weight. I am a vegan and it made me concerned. I spoke to the doctor I had at the time about it and he said "eat less", So I did. I gained more weight. I kept complaining so he sent me to a nutritionist who spent more time telling me to go back to eating meat than trying to help. I had been measuring and logging my food for aa long time but I had never really calculated the calories.
After doing some reading on the web I sat down and using a calorie counter calculated the calories. Turns out that on a good day I was getting 500 cals. On most days it was between 100 and 250.
I decided to bump my calories to making sure I ate at least 1000 and then now to at least 1200. Since I started - many slips where I overestimated the amount of calories in the food I consumed but I have lost 30 lbs. It took me 8 months but it still makes me happy.
You can absolutely gain weight on too few calories.

That said, initially when I bumped my calories I jumped for 221 to 232 the first month. After that it leveled off and I started losing. I read somewhere that it can sometimes take the body 6-8 weeks to adjust so just be patient. If you try it for a couple of months and it does not start giving results then try tweaking your foods, drink more water, etc. Try to just more by your clothing. Make sure you do some kind of toning/weight resistance even if it is just 10 mins 3 times per week.
Good luck

Your body could be adjusting to the new diet. I would suggest getting some exercise in there as well. Getting thin doesn't mean much if you are still unhealthy!

One mistake a lot of new calorie counters make is eating more packaged food because it is easier to read the calories. That means you are going to be eating way too much sodium! Others tend to only eat fruit and veggies which can cause problems because you also need some complex carbs and protein.

You are probably UNDER estimating your caloric intake and OVER estimating your work outs

It pays to double check the serving size. I was getting shafted on breakfast cereal. Apparently the 'serving' size is only a few tablespoons! Another time I had to reduce from 2 pieces of gluten free toast to 1 as that stuff is solid. :-) but early days. Don't panic.

Weigh and measure all the things O:

Also, being female, as am I (the photo gives it away), I fluctuate between 2-5lb of water weight during my period which is frustrating to tell you the least but there's nothing I can do about it!

You've got to keep going as well, just a bit of a set back shouldn't throw you off completely!