DDs with opposite weight issues, supporting one without failing the other

[dutchmanhattan67]

DP's DGD is 3 years older than my DD- we had DC at completely different life stages! DD is with her dad one night a week and EOW, with us the rest of the time. We have DGD and DGSs from one of DP's DC overnight regularly. Usually 1-2 nights a week but sometimes up to 4.

DGD has been referred to CAMHS eating disorder services. No diagnosis yet but lost a lot of weight, restricting food, struggling with body image etc.

DD is overweight and currently has a really awful relationship with food, and I'm finding it harder and harder to support DGD when she's here without feeling like I'm failing her. DD's dad is useless and feeds her rubbish when she's with him, so I really do need to be trying to tackle her weight while she's with us. Ideally without making her aware of it. Both of them have issues with portion sizes but in opposite ways, and I'm finding we're allowing DD to overeat in treading carefully around DGD.

Does anyone have any experience managing two DDs on opposite ends of the spectrum like this? At the moment I feel like I'm failing one of them whatever I do.

Bumping for evening traffic

How old are they?

Could you serve up the meals so there isn't the opportunity for your DD to overeat? I do this and I portion up leftovers into tupperware straight away so no seconds. (For me though as I have a tendancy to overeat) if dds are hungry later there's always fruit, crackers and we always have a small pudding.

And if DGD eats some of a healthy dinner that's better than none? If she is struggling with her body image she might be more inclined to eat something healthy.

But for your DD I would focus less on food and maybe look at clubs or activities to get her active. Could you go to some with her as a mum/daughter time?

What we did was to prepare healthy food but then add extra calories for the child that was underweight. This was under the advice of a dietitian since one child went off the bottom of the percentile chart. We were told to do this by adding butter to vegetables (I melted some in a milk jug in the microwave then poured it over.) Also adding more cheese to the underweight child's food. We were told to introduce a fourth meal, supper, before bedtime as a way to get additional calories in. That might be tricky to manage in your case but you could always give one child a piece of toast and the other two pieces of toast if you decided to try it. My DS was on Paediasure nutrition drinks for two years as a source of extra calories. He had two a day at first then went down to one a day as his weight came back into the normal range. Those might work well for you as they don't actually taste that nice so your child that isn't underweight isn't likely to want them as well. You can buy them over the counter but we managed to get ours on prescription which saved a few quid.

I was the overweight child in this scenario although it was with my sibling and we lived together. It was a total nightmare. My parents didn't handle it brilliantly but did their best with what they could.
I'm not sure why you're parenting your partners grandchild so much and presume there is a contributing back story there? The reason I mention that is because whatever it is, will be affecting your own daughter and as harsh as it sounds, at some point you have to show your own child that they are a priority to you. My parents never did (and I get it, anorexia is usually much more dangerous than overeating especially in the short term). But never ever being able to ask for help because they were so overwhelmed with my sibling was awful. I ended up eating for my sibling and bottling everything up.
From the perspective of the overweight child, I think an extremely careful, positive approach can work. My Mum was tactless innthe extreme. I would have liked a lot of positive uplifting messages but done in a private one to one way. No diets, a focus on health and wellbeing, and fun in my life that didn't revolve around food. She will be extremely painfully aware of the situation and the shame which is doubled by her opposing problem as well as the guilt she may be causing it. Tread carefully.

What do they both have in common? There is probably a lot of stuff you can do to benefit their mental health generally that will work for both of them. What kind of time do you all spend together, do you have things that you/they all like doing like the cinema or board games or whatever. But a table tennis table or take them to mini golf or whatever works (I don’t think you actually said their ages?) but focus on their happiness rather than/as well as their eating.

I have this exact problem too OP with my two DS and it’s a nightmare. Eldest has SEN, very underweight and medication stops his appetite plus restricted in what he will eat. Youngest is very food oriented and slightly overweight.

i also really struggle with how to balance their needs. At the moment I feel like I’m potentially giving them both food issues

Focus on own dd with healthy meals and portion size for everyone. I wouldn't be secretly adding calories to dgd food.