Suggestions for change phobic partner

Last night my partner weighed himself, and promptly sat down with a cider and informed me we BOTH need to loose weight. He's been overweight for a while now but of course I could not force anything upon him. If he wants to loose weight its got to be because of his own personal motivation not because I'm slipping him laxatives and locking the kitchen door. I've been trying to get rid of the excess cake belly a while now and have just started the 5+2 diet (and increased exercise and general step away from the sweet jar fatty) so want to do my best to support him although I know that what works for me wont always work for him.

Unfortunately my partner has a phobia of change, even a small change to his routine upsets him (think autistic - there is no rational side to it) so helping guide him towards a programme / new way of life isn't always easy. He has also spent the last 8 years living with a mate where their portion size and (lack of) control meant you'd often find them eating enough for a family of six. I worry his ability to feel full has disappeared and his stomach has stretched / been programmed to feel hungry long before he needs to eat (he'll often have two slices of toast upon coming home from work to "tide him over" until our main meal at 19:30). Is it possible to reset his gut / brain interactions?

Can anyone suggest things I can offer up to him to see if he is willing to try them? I feel he works best to structured approaches rather than a "just eat less" concept which though easy for most will mean nothing to him as I don't believe he's really aware of how much he eats during the day.

Ideas he has already dismissed (he is always very quick to say no!)

5+2 diet or anything that involves his not eating for any length of time: he fears he will gorge on the "feast" days and undo all the work (he has no self control and no grasp of feeling full).

Joining a gym: he is saving all available funds towards a house / repaying his car. We have already tried having a 6 month gym membership (at his suggestion) to the nearest place and he failed to even complete the induction. I thought about using some of my savings to buy him a gym membership for three months. Would this be a really bad idea?

Going out cycling: he sweats EXCESSIVELY and also has extremely bad hayfever for the next few months. He's not sure he'd make it to the end of the road. I thought about suggesting night time rides to him as a way of getting round the heat / self consciousness or getting a stationary cycle to use til he slims down enough that he can go outside without being too aware of people staring at him. Can anyone recommend a stationary bike?

Getting work out at home DVDs: as he points out the house is so flimsily built the neighbours washing machine on full spin shakes things off the walls and out of cupboards and they can hear us tiptoing up the stairs. He thinks any attempts to be energetic will result in a wall coming down but isn't interested in the likes of more gentle exercise (i.e. pilates).

Putting down the treats. Short of my taking his wallet off him its not going to happen in the long term and I'm not here to mother him. He knows he has no self control its up to him to do something about it.

Has anyone used a website / app where you can work out meal plans for a week and it show portion sizes / calories / fat content etc ? I think trying to programme a weeks work into MFP would be a drag and he'd loose interest. I was thinking of a site where you can enter in the meals for the week and print it out to put onto the fridge as a structured reminder would make him more aware of how much you SHOULD eat rather than it be more focussed on how much CAN you eat.

Thank you :)