This Is Us : The one thing that I can't suspend disbelief on w/ this show

Don't get me wrong, I like the show enough for what it is, but there's one thing that hasn't jibed with me in the least for this whole first season. How could Kate (the obese daughter) ever get to be anywhere near that large with her parents being the small size that they are, genetic-wise? She likely weighs well more than both of her parents combined. How do you have Mandy Moore as a mother and an adonis for a father and ever become that large, even if you willfully let yourself go as much as one possibility can? It's just one of those things that really rang as completely implausible to me. Add to the equation having another adonis for a TWIN brother. It just doesn't make sense to me at all. Please explain/enlighten me?

Another thing is we have never seen Kate (young or grown) even come close to eating the amount necessary to gain or maintain that weight minus a serious medical condition. I eat more than it appears she does.

But Kevin being her twin isn't really any more relevant to Kate genetics wise then it would be if they were single birth siblings born years apart.

You aren't just the product of your parent's genes. You have genes from 2 parents, 4 grandparents, 16 grandparents, going back a long time. I've seen people whose parents are African American and have a kid who looks like Ron Howard. My dad had blue eyes, my mother brown, my eyes are green - the only one of 4 kids with green eyes. Maybe there's a wonky chromosome in Kate. Who knows?

Having two parents who are thin doesn't preclude one from being fat if you don't take care of yourself.

You're relating something like weight far too much to genetics. It's possible for anyone to get fat. It's simple mathematics. Eat enough calories and don't exercise or burn any of them off, you'll get fat, regardless of what your parents looked like.

There are endocrine disorders and metabolic issues that can be carried but not displayed in a parent, but show up in a child due to environmental influences such as chemicals, living near pesticide-filled corn fields, bodily stress, going on the wrong birth control, poor diet, etc. You can "have" it but have it never be triggered yet if it is triggered, oh it comes on pretty fast. As well as having grandparents that carry the predispositions to the causes as well. I have one. My mom is thin, my dad's mother/my grandmother had type 2 diabetes, as well as her daughter/my aunt. My dad does not. But here I am - due to other bodily stress and environmental influences, mine was triggered. Luckily under control now, because it was caught early enough. Those with these kind of predispositions to metabolic issues, hormonal issues, etc that make it hard to lose weight but get that overweight are usually able to get that overweight because they never seek medical insight. (What I have is PCOS, an endocrine disorder that can bring on rapid weight gain due to hormonal imbalances that influence one to have insulin resistance which may lead to diabetes if left untreated)

I have a cousin who is quite large. Both his parents were petite. However my grandfather(who was his father's father) was tall & husky(not fat, but could have been if he ate too much). All his eight siblings are slim, including his twin sister. She did get quite large when she was pregnant(so you could see where she could have been). She did lose the weight again, though. So like someone else mentioned it's not just the parents/siblings you look at.

The obese daughter of a supermodel and Olympic basketball player..https://www.youtube.com/watch?v=1y_Ghyhph8o

Having had actual experience with a diagnosed eating disorder in a family member (and there is no doubt that Kate suffers from an eating disorder) I will say what a very smart therapist said to me many years ago:

Eating disorders are usually the result of a PERFECT STORM of things. As others have said, genetics plays only a small part in it. So many factors play in to it. Nature/nurture. All of your life experiences. Something that happened in childhood - doesn't need to be a huge traumatic event.

Actually, eating disorders are very similar to addictions. Jack's alcohol issues are definitely part of that perfect storm.

Just my opinion based on many years of family therapy.

Well I cannot understand why people cant understand that Kates delimma is very realistic and does happen. The fact v is just because skinny pretty parents do not alway produce kids who look like them. Life doesnt always work out that way. These things can also be left up to several variables. In Kates case, she clearly stated that her body reacted to food differently than her mother. She was always hungry and her mothers skinniness created some physical and emotional issues for her. Personally, I can see how that created issues with her gaining weight and creating a poor self esteem especially since Kate grew up during a time when there wasnt as much education about nutrition. People were also still learning about food, nutrition and it effects on certain body types. It was not luke it is today. So I really dont see why Kates weight is a hard concept to grasp edpecially since she has addressed it on the show.