I would appreciate anyones advice please.

After having my bitch speyed she has steadily put the weight on. I did reduce her food down by a third (complete dry) and mix more veggies in.  She is an active dog. She gets a good two hours walk a day, does agility and swims twice a week.
I have had her at the vets and ruled out anything healthwise but the vet wasn't helpful with a diet just pushed the science plan at me.
She was on royal canin adult orginally, then canin light, then tried chappie with veg, james wellbeloved, burns (gave her the awful runs)
The thing is if you read the suggested portions on the food it is way more than what I fed her when she wasn't spayed.
I want to measure her food in calories but the food i've had doesn't do a breakdown say per 100g.
She is a small border collie bitch who was 17.5 kilos pre spay. She is now 26.5kilos. The vet says she only needs to lose a kilo and a half which i don't agree with.  I think around the 20kilo mark would be acceptable for her taking into account she's older now and she was very lean at the time.
Could anyone suggest foods they would recommend. Someone said rice but again, it is high in calories and she's not mad on it.
This weight gain has been over a year so I haven't chopped and changed week by week but over say 2 month periods. I have changed from one meal a day (evening) to splitting it into morning and evening feeds.

The only way to do it is cut down the food again.  I never take any notice of what the recommended amounts are.  Bulk it up with vegtables. 

As long as you are using a good quality food, which I rate Royal Canin as one of the best, keep lowering the amounts.

Bit like us going on a diet really ;)

I think Royal Canin really puts the weight ON though. I took part in a trial about a year ago -was approached by a rep. They wanted one of my dogs on RC to see if she would improve in any way compared to my other dogs that were still on Gusto. I explained she puts on weight eaisly,so I was given a food (can't remember which now) that wasn't meant to add weight easily, and was told to give even less than the recommendations. She gained so much weight I had to stop feeding it -this was just a few weeks before Crufts. She was constantly hungry as well as the portions didn't satisfy her at all.

Thanks guys for your advice. Sandrah have you come down to earth yet :)
I have split her meals into two a day. I do like Royal Canin but when I put her on the lite it did nothing for her. Spoke to my breeder who said yes the light had put weight on her bitches in the past and she recommended chappie for a bit. Didn't work and Meg hated it, just left it. I have put her back on royal canin but honestly just give her a handful then the rest is veg. She has about a fifth of what she used to have pre spay. I'm not personally fond of giving raw. It's just me. I do give my other dogs raw tripe and that's about it.
I don't get it as the amount of exercise she gets she should be easily burning of the calories compared to what she eats.

I have fed my BC's raw for ages & started the GSD(who tends to to put on wieght) on it sometime ago. Be warned don't pulp up carrots as this releases the sugars so chunky is better Have you thought of feeding her raw ? The time it takes to eat frozen chicken wings,legs etc can mean that she takes longer to eat & therefore looks for less food

You could also try splitting up her food into two or more meals so her calorie intake is spread out over the day & she uses the calories on a better basis(LOL I'm a diabetic & this is what my regimne is & yes I have lost weight too)