To think that obesity mostly has to do with your genes

[penandpaperlife]

I've been living with my best friend for a year now due to some personal issues with my STBXH, and this has been something I've been wondering about. My best friend eats the exact same thing as me, with the same exact portion size. She also snacks on nuts and/or biscuits throughout the day (we're a freelance team so we spend basically all day together) while I don't.

Why then, is she slim and I'm not?

The only difference in our lifestyle is that she goes for a 15min run every morning. I've read studies and charts though and that seems to only burn about 150kcals. Surely that wouldn't even offset her snacks? I come from a 'fat family', she doesn't. We're both almost 30, if that matters. That leads me to believe that genetics do play a huge part here, contrary to what's often being parroted in the press. Is that possible? Does anyone have any experience with this?

This is really interesting I have no idea

Go for the run and move around as much as she does and see if you lose weight.

My whole family is/was very overweight growing up as a child so was I now I'm not. I eat better and move more.

Studies have shown that when people keep food diaries they massively underestimate what they are actually eating. I’m sure genetics play a small part but if it really was just genetics then wouldn’t there still be overweight people in areas of extreme poverty and famine? yet You never see that

Your flatmate's exercise isn't just significant in terms of burning calories, she will continue to burn calories after the exercise, and probably also has greater muscle mass, so burns more calories over the whole course of a day.

wouldn’t there still be overweight people in areas of extreme poverty and famine

yes I was going to mention WW2 and late 1940s rationing. Was anyone overweight then? I don't think so, everyone was very thin unless they were able to get extra food somehow. I still think generally it's a simple case of food in and exercise out.

How tall are you both?

Gut bacteria are probably a major factor.

Professor Tim Spector of King's College London has done some really interesting twin studies on this. He's got some YouTube videos and has written a book called The Diet Myth which is great.

I am the only fat one in my family. My paternal grandmother was 'plump' ie a bmi of somewhere around 26/27.

Everyone else on both sides of my family is and always has been a moderate weight. I struggle to keep my bmi under 30 and the lowest it's been as an adult was 25.

The main difference is activity. They are all active and I am a human sloth or, as my husband once said 'the most physically lazy person he's ever met'. So food isn't madly different but energy is.

genetics works that way in our family I am slim my 3 children are slim and my grandchildren are all slim my ex husband was also slim I eat normal food snack and don't think about what I eat

Keep telling yourself that....

Came here to say the same as @Lumisade - microbes are likely the big key here. Read The Diet Myth, completely changed my view of the world and health in general, let alone weight. I’m still chubby though!

I'm sure there have been studies saying certain genes are associated with obesity, but not enough for it to be an overriding factor.

Obesity is almost entirely lifestyle related.

Your flatmate's exercise isn't just significant in terms of burning calories, she will continue to burn calories after the exercise, and probably also has greater muscle mass, so burns more calories over the whole course of a day.

I've never actually thought about this.

Re how tall we both are, I'm 5'5" while she's 5'3" so not much difference there.

I've looked over photos going back about 100 yrs. Nearky all the women in my family are the same ...short (well about 5.4, perhaps that's average) and overweight ...including during the war when there were rations.

My takeaway from that is that we are more prone to wright gain and need less calories than the average person.

I eat what I like and I follow my family build.

Loads of them lived well into their late 80s/early 90s

Nope, not necessarily. I've put on masses of weight because I've spent the last few years eating like a rhinoceros, especially during pregnancy. Everyone I know who is overweight eats similarly.

Even though I'm fairly sure they have discovered a gene that makes people more predisposed to holding onto fat, it still doesn't make it your destiny to be obese.

If your friend genuinely eats the same as you, her body composition could be different. Muscle mass is more biologically active and uses more energy than fat, and people even of the same weight and height can have really different body compositions.

I'm certainly not saying genetics have nothing with weigh loss or gain, they simply must do. But if she runs every single day, that suggests she could also be more active just in day to day life. They say even fidgeting can burn like 300 more calories a day!

YABU

I am obese, a lot of my mum’s side of the family are the same, I do think I have a tendency to pile on weight more quickly than a lot of people who eat the same but I am pretty sure if I lived somewhere with a shortage of food I’d quickly become not obese. Genes may have an impact but you can still try and control it.

No. YABU.

Obesity is a very Western problem, where food is in abundance.

It's calories in vs calories out, plain and simple thermodynamics. Human bodies cannot break the laws of thermodynamics, no matter how much we'd like to believe otherwise.

Thank you for the link Lumisade. I'm watching it now.

There's much more to it than we used to think- gut bacteria as a pp says, also something about the interplay of hormones, and a particular illness in childhood (can't remember that one).

That said, increase your activity levels to match your friend's and see what happens.

If someone isn’t losing weight they are not in a calorie deficit.

A body can only store fat if we give our bodies the ingredients to do so. People who claim to not lose weight on 1,000 calories a day are either liars or defying the laws of physics.

The exception is of course people with water retention, but that’s something you can spot a mile off due to the distribution.

The exercise will have a bigger impact than just the 150 kcals used during the run.

IIRC, people who have more muscles burn more calories when at rest than people who have less muscles. Exercise builds muscle.
So all else being equal, someone who’s fit and exercises regularly will have a higher resting metabolic rate than someone with a sedentary lifestyle, and if both people eat exactly the same, then the one who regularly exercises is likely to be thinner.

If you both did exactly the same amount of exercise as well, then you’d have a better case to make about your genes.

Does your friend have the fidget factor?
Even when sat down at night I’ll be fidgeting, jiggling my legs.
I’ve always been slim. I do eat small portions too.

It's calories in vs calories out, plain and simple thermodynamics. Human bodies cannot break the laws of thermodynamics, no matter how much we'd like to believe otherwise

Totally agree. I have yet to see an obese person in those horrific concentration camp photos from the war.