From what I understand, Prader-Willi is a package deal. Because it is a genetic condition (part of one chromosome displacing another part - highly specific), it MAY be possible to have a slightly lesser degree, but in this case i don't think so.
difficult child 3 has a drama classmate with Prader-WIlli. I won't say they're friends - difficult child 3 can't stand him because this other kid is always mucking around and being difficult. But from what I've seen of this boy, he is a sweet kid a lot of the time and his mother has managed to keep him only mildly chubby. Frankly, he looks normal. But this is at a HUGE effort.
I very much doubt this is Prader-Willi. It's generally found in infancy, often at birth when the absence of a gag reflex is found (and they always test for gag reflex). This mother told us that part of the syndrome is an inability to vomit (or maybe not vomit properly, or only rarely). This is such a problem that if he eats something bad (which they will - it's food, they do not discriminate) they need to go to hospital and have their stomach pumped.
The insatiable appetite in Prader-Willi comes from an area of the hypothalamus not working - it's the part that sends signals to the body saying, "I'm full". It is the part which received signals from the blood sugar levels and from the stretched stomach saying, "I do not need food." And without that signal, the person ALWAYS feels as if they are starving, even if they've just eaten a huge meal. A Prader-Willi can literally eat themselves to death - and not just eventually from heart disease. Unsupervised, they can keep eating until their stomach literally explodes. They simply do not feel it.
It is a matter of degree - it is probably several orders of magnitude worse than Lucas is now. And I know that is saying something.
My friend at drama class (the mother) was telling us about her recent birthday when the family went to a restaurant for dinner. It had a buffet - a big mistake, it turned out. The boy began loading his plate high with everything he could get, he was grabbing at food. His mother took his plate from him and began to offload his food onto another plate so she could ration him - he began screaming, "That's MY food! Give me my food! I'm starving!" over and over. He was grabbing at her, grabbing at every plate within reach and eventually they just had to give up and go home.
And this is a well-controlled Prader-Willi.
I've seen her give him a treat - they do not buy milk in bottles any more, they only buy the small single-serve sachets of milk. A treat for him when he is feeling ravenous (all the time) is to be given ONE of these which he has been taught to sip slowly.
Of course it doesn't last and his mother has locks on all the food cupboards and the fridge. At the drama class they have a biscuit tin and tea/coffee things. We have to lock up the milk while the kids are changing over the class, to keep this boy away from temptation. It's just not fair. He still gets to the biscuits but is limited to just one. Where possible, they try to hide the biscuit tin from him too.
Your son - was he on risperdal? You mentioned something which sounded like it. difficult child 1 did lose his risperdal weight when he went off it, but it took about a year. He didn't lose it all, but he is finally skinny again.
Your husband says to not keep snacks out of the house entirely - sorry, husband. This has to be a rule for everyone, or it's just not fair on Lucas. It's hard enough on him, others should make sacrifices - and it's a healthy sacrifice anyway. If husband wants his snacks he can have them at work. You HAVE to eliminate rubbish from the house or it will be found and consumed. Or smuggled in and you will think it's just husband or easy child. Whereas if the entire family is going on a health kick, then it's the whole family. And make it a fitness kick too - take resting pulse for everyone and put it on a chart. Then each person do five minutes of exercise to get the heart rate up - if you haven't got an exercise bike and people don't want to jog, then stepping is good. If you have no steps, then get some phone books and use those as steps. You can always find something. Then measure pulse immediately you stop the exercise, then after five minutes. If necessary, measure pulse at five minute intervals to determine how long it will take to go back to that person's resting level.
Teach each person to take their pulse - count beats for 15 seconds then multiply by 4. Or for ten seconds, multiply by 6. The shorter interval as the pulse is slowing post-exercise gives you more of a snapshot of your pulse, it will be more accurate.
And make everyone do this - not just Lucas. He might find he's no longer worst at something, and being young he might make better progress than, say, husband. And if husband is still insisting on his own supplies of junk food (maybe at work) then this increases the chance of Lucas 'winning' compared to husband.
If you can, set up a daily (or three times weekly) family exercise session. Begin with simple stretches (don't bounce into the stretch, just do it gently, hold, then release - never push to the point of pain) and then move into exercise (half an hour if you can manage it) and then more stretches to cool down. Monitoring pulse is a way of monitoring increasing fitness for each individual.
And on other days - each person can 'cheat' by trying to surreptitiously exercise to get their fitness up faster. Walking is perhaps best of all, if Lucas is starting from a point of reduced fitness. Or he could go to the gym with you and maybe find some of the machines can be fun. I used to reward myself at the gum by getting a swim or sauna afterwards. A special treat afterwards can be a healthy treat such as a frozen fruit ice block, or frozen fruit puree in a dish.
Find healthy junk food which he can eat whenever he likes. Maybe don't suddenly go ultra-strict on his diet - simply removing the worst junk food can bring a fair bit of improvement. Savoury popcorn can be really good as a snack, you can get flavoured salt instead of using real butter. We pop our own popcorn and have home movie nights sometimes, pausing the DVD to get up and make more popcorn.
Home-made pizza - I use a bread machine to make the bread dough base, then add our own toppings. I often use low-fat cheese (which melts like mozzarella) plus a small amount of freshly grated parmesan, for a cheese flavour boost without all the problems. You can monitor your own toppings, make plates of toppings available and get people to make their own pizza (from YOUR range of ingredients).
You can provide a healthy diet by avoiding the textures and flavours he can't tolerate. Asian stir-fries work well for us - again, we try to avoid ingredients that the kids dislike. Alternatively, we cut the pieces larger than usual to make it easier to pick them out - easy child 2/difficult child 2 hates onion, red or green capsicum, broccoli. So we cut those pieces large enough for her to pick them out and give to someone else.
Growing your own vegetables can also work really well for kids who need to eat healthy food. You can get the more unusual varieties (such as yellow tomatoes, blue potatoes and so on) and see how the kids go. Get the kids to help plant and care for the veg garden and they will learn to appreciate the food more. I planted a lot of parsley (too much) and now difficult child 3 picks a small piece and nibbles it. I've got sugar snap peas but rarely have enough to harvest for a meal - difficult child 3 eats them raw. My cauliflower took two years to mature (a failure) but the tomatoes are beginning to look promising. When I've had tomatoes before the kids really value the intense flavour of tomatoes allowed to fully ripen on the vine. Nothing compares to that! I grow a lot of herbs, the kids are sent to pick some for me for various recipes. Sometimes they pick chives to nibble, as well as the parsley.
Case in point - I bought some apples for husband and he hasn't taken any to work. I just gave one to difficult child 3 to eat while doing his schoolwork and he brought me the seeds - they were already sprouting inside the apple, he asked me to plant them for him. And we just were talking about why and how seeds sprout, still inside the fruit. He will probably eat more apples to find more sprouting seeds, and also watch those seedlings to see what happens.
Discovering food can be a real good way to diet. Sounds crazy, but it at least makes for a healthier person. We buy fruit and vegetables in season, the kids are encouraged to eat as much as they want. If they eat all the carrots and I was planning on cooking some, I make sure I plan and buy extra. I buy a bunch of celery and the kids eat it fast, often spreading it with Vegemite (Aussie treat - always use it sparingly). Another celery treat is cottage cheese and sultanas. Or dips.
I gather Lucas doesn't like creamy textures - how is he with yogurt? I have a savory dip recipe which is fabulous (tastes very bad for you) made from yogurt. Tzaziki.
Eating more food isn't a problem, if he's eating healthy food. OK, bananas have a lot of calories, so do apples, but if he eats six apples in one sitting he's also getting the fibre, as well as a taste for raw food. All of this is good. The same number of calories of a processed starch snack will sit in his stomach and ALL get absorbed, whereas the apples will be moving through his GI tract faster and pull other things with them.
If, after merely eliminating rubbish and replacing it with unlimited fruit & veg, he is STILL gaining weight unhealthily, THEN you can bring in calorie control. But don't cut out everything, or too much. Keep a food pyramid inside the pantry door or on the fridge, to remind the family that there are healthy options now available.
And watch out for diet foods - they often make things worse. A lot of low-fat foods are still highly processed and compensate with extra sugar - very bad. Low-cal soft drinks still keep you programmed for a sweet taste. Add in that they are unsatisfying when you have a sugar craving, and all they do is send you off in search of the real thing. If instead you had slaked your thirst with a glass of milk, or water, you wouldn't have that problem.
I was drinking skim milk for a long time, until I realised that taking out that 4% of fat meant that there was another 4 mls in every 100 mls with the extra 4 mls worth of lactose. That's why it tastes sweeter. It's also absorbed much faster - the fat slows down absorption.
So don't put him on a diet, just put the whole family on a junk-free, additive-free unlimited food diet, plus maybe some regular exercise to monitor increased fitness.
Good luck selling it to husband! If you can sell it to him, you should be able to sell it to Lucas. You and Lucas can laugh together at husband's snack food cravings!
Marg