Your kids will have a different genetic makeup, and there will be so many years between them that she will not be a great influence on how they live. They will not be overweight because of SD.

It's not a good conversation to start unless you want a bitter argument. He'll see it as an attack on his daughter and on himself as a parent.

Her weight might bother you, but overall it isn't your problem. Ignore it and let her be. It's DH and BM's making.

You need to stop worrying about her. She's 16 and you're not going to have much impact on this if your DH doesn't care enough to really step up to the plate.

As for children together you don't need to worry about how she will influence them. Just because she's overweight doesn't mean you can't raise healthy children. Also she should be out of the house soon enough that really she wont have much impact on them.

I would stop worrying.

Has anyone had her checked to see if she has an underlying medical issue that is either causing or contributing to her weight gain? While she seems to have some rather typical teenage laziness, that might not be the only reason she is overweight.

IMO do not bring SD up when talking about how you want it to be raising your children. You can talk about how you want active children, setting boundaries, and proper parenting without mentioning her name. Let your DH know how you see raising children keeping them fit, active, healthy, behavior with consequences etc. Encourage his input, and maybe ask what he believes he would do the same and/or different the second time around.
Good luck

You have tried with your sd but she is not interested right now. Maybe one day she will be and she will come to you for advice. But right now she has to have the internal motivation or it won’t work. So leave things be.

As for your children, they will be different people, have different parents and are being raised in a different household to your sd. They are not destined to follow in her footsteps and even if they do, you will discover as a parent to overweight children thatbthere are worse things that could happen to them than being over weight.

As for now, there is nothing to talk to your husband about. Your children have no issues right now, they have not even been conceived. Save the conversation for when your kids are teens and getting a bit overweight, and even then, focus on your children, not sd.

You will also be a parent to your children, so you can instill healthy habits in them starting when they are young. You mention dogs, so make it a regular thing that your kids go out with you to walk the dogs - even in a stroller before they can walk. When they're teenagers, walking the dogs will be so much of a habit that they won't think twice about it. Also, do lots of active things with them. Part of her issue could be that she was never encouraged to be active. Part of it could also be teenage laziness. Usually incentives like "no iphone unless you exercise" don't work. I also wouldn't try to control her. She has to want to lose the weight herself for it to happen. No one else can make it happen and making her feel shameful about it will likely only make it worse.

Sounds like her mom instilled poor eating habits, and she may very well be too old to change them.

I had the same problem with my SD. Exercise is really only a very small part of the problem, the major issue is diet. There are two documentaries you can watch on Netflix, the best one is FedUp and the second is Bite Size. The culprit is sugar. No one should be eating that crap, and the whole household could benefit from the elimination of that crap from their diets. I'm not just talking about candy and cookies, I'm talking all refined starches. You can take steps now to make your whole household much healthier. If you are the person who does the grocery shopping for the household, just stop buying it. I did, and we all lost weight, and we all feel better. We still have treats once in awhile, just not even close to every day.

My mom died of metabolic disease at a young age. It's a freakin epidemic. It's the reason our healthcare budgets are in collapse.

Another thing you can look at if you want is the fact that we all also eat too much meat. Way too much. A serving of meat is no more than 2-3 ounces, but really, we can go days (or forever) without eating it. Fat Sick and Nearly Dead is a good documentary for that. Meals should be at least 50% vegetables and whole fruits. Starches should be whole grain and 25% or less of the meal, protein should be 25% or less as well. There are a lot of yummy vegetable dish recipes out there to learn.

And if you think she has too much screentime, you could try taking away her phone when she is home, or cancelling cable tv, but she might just nap more or spend time reading or something. You could try enrolling her in a sport, but really, she's not your problem. When you have your own kids, you can TELL them it's time to go for a walk, and they will have to because you are the mom. They will enjoy playing with you and spending time with you.

I love the term "step-pig". That so fit SS32 who I met as an adult.

Before I banished SS I sent tons of good tasting nutritious food to him. But a glutton is a glutton. One cannot change what a pig eats.

Overeating is a psychological issue.