This is what they do at my gym for the older/new/outta shape people, i've watched this several times.
For someone totally outta shape and over weight your not gonna start them off on a "advanced" program, the personal trainers take the person, and use the hammersmith machines, 1 exercise for each body part, 1 for back, 1 for chest ect. the first think they do is find what weight the person can handle for 12 reps, they have a note book and record what they can do. They do that to each machine they go to, then the next week they start them with 1 set of 12 reps, if the person can do all 12, the next session they bump up the weight 2-5 pounds, they usually train the person 3x's a week, M/W/F.
Seems alright for the older people, as far as diet, i'm not sure, but above is what i see going on in the gym i go to.
I can't say if this routine is effective or not but it gives a good idea of something you can create on your own if you wanna. I see them doing this to people of all ages, and it seems to help.
Hope this helps abit beast.
good luck.