I don't know what the water diet is as i don't keep up with specific systems of dieting that people make up. However i will say that water is probably the BEST thing for her whether she is dieting or not and plenty of it. Walking is good too.My girlfriend wants me to help her lose weight..?
If she has health complications then she really should get advice from a doc about weight loss so things won't go bad for her.
thee is something called a lemonade diet it works or you can order a video tape called zuma its a proven dvd/video that has helped plenty of people i know drop alot of weight and i mean this one woman was a big woman and weeks later she looked great but i didn't know how she did it until she looked over at me and said its zuma baby ... so try it good look to you and your girl. i promise it will work.
You should go jogging with her, encourage her.
Do light cardio exercises such as running, jogging, things that involves jumps, ect.
However take it easy if she has heart problems. However a nice run together would most likely drop some pounds, make you two fast, strengthen her heart and have time for you two to bond. Hope this helps!
(P.s. If that doesn't work she can always try the more heavy stuff like light weightlifting, though I wouldn't recommend it.)
Have her watch the Biggest Loser. The best method is always exercising. Diets never work unless you exercise as well, and they're actually the most effective if you eat the RIGHT kinds of things (not dieting like cutting out whole food groups). I believe someone already suggested a sort of work out regime. I also think it would be imperative for her to talk to her doctor about it as well if she has a heart disease.
To answer your water diet question: as far as I know, it's just drinking a LOT of water while maintaining the same eating habits. Keeping your stomach full with water reduces hunger cravings, and it also flushes out your system. However, it's imperative to still eat, and to exercise, to get the best results.
Try the shocker. Two in the pink and one in the stink. She will love it.