I get the feeling that most failsafe advice is geared to children and families, and definitely not to adults who share living, cooking or work spaces with other independent people and who have jobs or study with requirements that have to be met.
I cook for myself only, share with one housemate who does his own cooking (I do miss pre-FODMAP when we shared cooking), and I am towards the end of my PhD which means a lot of late nights and sometimes working on weekends. I am also quite social, so a couple of evenings a week are spent out at soccer practice or choir rehearsal which restricts cooking. I like to be a part of events with friends even if they are centred on food. I find I need to cook main meals about 4 times a week – at least two nights a week and twice on the weekend – as well as bake one sweet thing a week for snacks and a batch of bread every 1-2 weeks. A weekend away requires planning at least a week in advance. I bring leftovers to Uni every day and bring dinner as well if I think I might work late. At the start of the week I make a rough plan of when I’ll cook to make sure I have enough to eat. It is a shame to turn down social events because you need to cook, but making sure you have time aside to do the cooking and shopping (including sourcing those difficult to find large white brushed potatoes and getting to the failsafe butcher) does help reduce stress. I just realised I am writing this as I should be doing the shopping. Hmm.
It helps to have some fall-backs if you don’t have time to cook or do the shopping. Keep some green beans, Brussel sprouts and hash browns (most these days have no antioxidants – but check first) in the freezer because they won’t go off. An extra frozen meal in the freezer can make a world of difference if you get home at 9pm after an 11-hour day and need to eat before you cook. Have a look at my last-minute recipes (to come) for what to make when you really have (almost) nothing. These are also good at Saturday lunchtime when you should have done the shopping but haven’t left the house yet! Going shopping on an empty stomach is never a good idea. My absolute last resort when stuck at Uni working late with no prepared food is a large bag of Kettle or Red Rock sea salt chips. It’s not healthy and you may feel sick from that much oil, but it is one of the few things that can be eaten straight from the shops, and is available in vending machines late at night.
In terms with dealing with sharing spaces with other people and not having control over your environment (as the failsafe books tell you to), I don’t necessarily have a solution but I can sympathise. As a chemist, I work with amines all the time, and I have had to teach practicals with both amines and salicylate derivatives – and you don’t necessarily trust students to keep their reactions inside a fumehood where they can’t be inhaled! I have done my best to minimise exposure and not do challenges when I know I will be exposed. Work with gloves and within safety procedures, impress on the students the need to keep the salicylates away from you, close the door to the co-worker’s office when they are wearing strong perfume and keep your food separate in the fridge. I brought in hand soap to the lab that doesn’t irritate me. At home I replaced the detergent/soaps/cleaning materials with ones that were failsafe and my housemate has been happy to use those. Luckily, as I’m not a coeliac, I don’t have to worry too much about contamination of cooking materials, or having a separate gluten free toaster. My housemate cooks “normal” food and I just make sure everything is washed before it is put away and then trust that it’s clean. My general advice would be to try and be self-sufficient, provide alternatives (with cost to yourself) and not impose on others as much as possible, but if something is really affecting you (say there are lilies inside the house giving you headaches), you have to say something.