Hi Grace - long time no hear!
I actually put on a lot of weight just because of PMR and not being able to exercise as I had before - not pred, I wasn't on pred for 5 years. When I started on pred I didn't put on significantly more weight but it redistributed to face, back of neck and midriff. Then I was switched to Medrol - and the weight went on big time! Nearly 3 years ago I was admitted to hospital and weighed about 88kg (just under 14st). I'm 5'1" in my socks. I was a total blob and I refused to even look in a mirror.
A few months later I was switched to another form of prednisone and have steadily lost weight since. At first it was barely noticeable but I changed my eating habits - I didn't eat much carbohydrate anyway but I cut it even further. I eat no processed carbs at all now. I eat salads and non-root veg most of the time. About once every 2 or 3 weeks I eat a couple of small pieces of roast potato with roast chicken (the only roast we eat). Portions of meat/fish are 4-5oz at most. I dress salads with olive oil and vinegar and dried herbs. I occasionally eat peas and carrots, never more than about 1oz/30g bread and that only maybe twice a week. Cake, desserts, pizza are very occasional treats - I don't refuse to eat them but they have to be special. I haven't given up wine.
I also used the 5:2 diet to kick start things - what it did more than anything was retrain my appetite and I can honestly say I am not hungry and if I do feel peckish I get something to drink first and that usually works.
It may sound boring and restricted - but I don't find it so. I find it is easy to have a wide choice of meals and it is food I enjoy. The real plus side is I have lost about 19kg/42lbs over a period of just 2 1\2 years, about 2lbs a month on a good month and a good 5 inches from my waist.
I do find that in a month where I have eaten more carb than usual - visitors or holiday where it is tempting to eat pizza, pasta or polenta (I live in Italy!) I don't lose weight. I don't gain either though. As soon as I go back to my normal diet I lose again.
David mentions "even the smallest intake is multiplied by Prednisolone in some mystical way". Pred changes the way our bodies process carbs, making weight gain and a predeliction to developing pre-diabetes common. If you remove the offending article - carbs - you help your body not fall prey to these problems.
Fruit is healthy - but it is also a source of sugars, carbohydrate and the carb count mounts up rapidly. Grapes are delicious - but very more-ish and very carby. There are other fruits that are less carby such as berries.
There is loads of info on the internet these days about cutting carbs, I particularly like a blog called the Diabetic Mediterranean diet where a doctor who is a diabetic explains the theories and practise of low carb eating. This isn't NO carb, it is LOW carb and so very healthy and is a diet that has been approved by the American Diabetic Association for management of diabetes. I find I have learned to get very good value out of carbs - a normal sized piece of cake from our baker is now 3 portions for me! I eat 1 bit and keep one for tomorrow and freeze the other - and it is enough. If you don't buy something you don't get tempted to binge.