I have been researching all day and there are far too many choices to decide 
One cat is overweight, she has rapidly gained in the last 6 months. No health issues, the vets believe it could be a combination of her being pregnant (stray) in the past and genetics. She holds her fat inside the tummy (this is a poor explanation, I can’t remember the exact words but it’s to do with fat distribution)
We have 3 cats, all eat the same and only she is gaining weight - she goes out, relatively active (no more or less than the other 2).
We spoke to a cat diet ‘advisor’ at the vets, but tbh I wasn’t impressed as she was pushing one particular newish brand of dry food only, even though I said cat will not eat it and I’d like recommendations of wet instead. She wouldn’t budge on alternatives and said we can just continue to feed her less of what we already do if we wish, or we could try the dry food she was offering. I’ve decided to just do my own research, but I’m non the wiser after today.
They all currently eat Gourmet Pate, not the greatest, but also after lots of wasted food, it’s the only one the cats will eat regularly.
Do we go with ‘proper’ weight loss food, do we with high meat content?
I’m struggling to know what else to look for, when I asked the advisor at the vet she said she couldn’t tell me 😐 but that we could contact her with ingredients from different brands and she could advise that way (and push the dry food again I guess)
I know there’s always the possibility that she could be eating when she goes out which is why I’m looking at possibly changing her food to a ‘diet’ one. She is very skittish and unlikely to approach people, but could still be coming across food on her travels.
Any advice/recommendations?