Hi,
Long time reader of the forums, but your topic struck a chord with me.
My mum is 81, has Parkinson’s disease, recently diagnosed with Rheumatoid Arthritis and is pre-diabetic. On her last visit to the GP the Dr told her to try this diet as she didn’t want diabetes added to her list of problems. She’s not very active due to her ailments so 800 cals is probably all she needs. She probably has a few more than 800 cals as she has a milky coffee and greek yogurt with strawberries as extras when she wants a little more. We were very lucky that the GP recommended the diet, and was also on it herself as she wouldnt recommend anything to her patients that she hadn’t tried herself.
I mainly follow the menu plans/meals in the book, which does contain good carbs of pulses etc and in the 8 wks shes been on the diet has lost 14lb, which considering her activity level is great. No blood tests yet, due some next month but she feels fine considering all she has been going through with the RA. Also, on the day we go the hospital for her RA treatment we go out for dinner, so she has a treat meal once a week, where she can eat what she wants within reason!
We have both found the diet very easy, i also had/have lots of weight to lose so have been on the diet too although a bit longer and have lost 52lb in 13 weeks, and am carrying on till i lose another 75lbs i think.
Hope that is helpful, as others have said monitor your mum and how she feels, plenty of water to keep hydrated, but rest assured my mum with all her health problems is doing well on the diet and hopefully can avoid diabetes!