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?

I read once that people whose recent ancestors suffered through famine experience epigenetic changes which make weight gain more likely.

Also somw people just move a lot, jiggle thier leg etc it burn a lot of cals.

No time to read it all but I agree. Went travelling with friends for 3 months as students. Ate the same stuff moves the same amount. At the end of it I had gained weight and looked awful. Skinny friend who ate more than everyone still skinny etc it’s ludicrous to say that there aren’t loads of factors at play here.

Start running 15 min every morning and see if it makes a difference

Not genetics, not slow metabolism or bigger boned.... basically it's an imbalance between the calories consumed vs those burned off. For genetics to be the answer there still has to be excess food eaten to turn into the genetically predisposed adipose tissue (which is a myth anyway), the chemical rate of metabolism is a fixed reaction - a bit like lighting a fire with plenty of oxygen, there's not a "slow burn", and bone density or overall volume doesn't have anything to do with the bodies fat that is laid down.

Oddly enough I bought I'd lose weight during the lockdown due to less visits to friends or to the pub. It turns out I'm snacking loads between meals and putting on quite a bit!

I’d check out Dr Bruce Lipton, he explains that nothing is hereditary

Dr Bruce Lipton isn't well regarded in the mainstream medical and scientific community. Having said that who knows, he could have a point?

I think there are some differences, I'm sure I've read of studies where people were given a regulated diet in a regulated environment / activity over several weeks. Some gained some lost some maintained which shouldn't have happened if everyone was the same. Some peoples metabolism and body temp runs slower and colder. It can also have benefits to have a slower metabolism, slower ageing.

I think people don't like to hear that there are differences because it sounds like an excuse or a cop out. I think that it should be seen as a opportunity for a more personalised approch to diet and weight loss.

What’s that twin study?

We conclude that genetic influences on body-mass index are substantial, whereas the childhood environment has little or no influence. These findings corroborate and extend the results of earlier studies of twins and adoptees. (N Engl J Med 1990; 322:1483–7.)

here NEJM

I learnt at university that genetics only influence obesity to an extent but when it comes down to it, you still have control.
So for example, genetically you may be more hardwired to underestimate how full you feel after a meal which might leave you wanting second helpings and a pudding. But you do have control of how big your portion sizes are and knowing that one portion is enough even if you’re not feeling full.

People's difficulty in believing that bodies can behave differently in terms of their response to food always amuses me.
There is very little our bodies do that is the same. whilst almost all women aged 30 menstruate, Some women will have a 24 day cycle, others a 32 day one. Some have heavy, painful periods, others have 3 days of painfree light periods. Some get dreadful PMS, some get sore boobs, others don't. Some people have teeth that are prone to cavities, others never have a day's problem with their teeth. Some people have thick, lustrous hair whilst others have thin hair which breaks easily. Some people grow to 4ft 9, others to 6 ft 3. Some people have allergies to nuts or find wheat bloats them or onion gives them heartburn; others don't. And yet for some reason the only reason for the variation in body mass has to be that some people are greedy and eat too much.

As I said in my earlier post, it stands to reason that body shapes and propensity to weight gain are inherited. Of course you can be a slimmer or fatter pear shaped person but you will never not have cankles or have Megan Markle slender calves if you aren't built that way. And yes if you are starving to death, no one will be obese. But obesity certainly existed in prehistoric humans as the various Venus figurines demonstrate. It may be as simple as calories in vs calories out on one level, but it isn't really as one person may gain weight on 1500 cals where another may not, and it's insulting and simplistic to say the only possible difference is that person A is lazier and needs to jiggle a bit more.

images.app.goo.gl/uRnwrYupacjD6cES8
The lovely Venus of willendorf who managed to become obese despite not having pizza or a supermarket nearby.

You really cannot change the Laws of Physics and essentially it really does come down to calories in Vs calories out. All the other reasons and excuses people have for being overweight play, at best, a very minimal role. For example far too many people assume they can eat 2000 k a day and not gain weight. In reality if you lead a very sedantary life then you probably only need 15-1600 calories per day to maintain your weight.

It’s multifactorial but a huge part is genes.

Peaceanddove:
So you don't think bodies may process calories differently? I am talking about the propensity to weight gain. Clearly if you become obese, you are eating more calories than you need. Are you telling me that there is zero difference whatsoever between the way/speed two bodies burn calories, their frame size, etc? Even though bodies differ in every other way?
So theoretically, two people both 5ft 4 inches who both eat exactly 1500 calories a day and both walk exactly 10000 steps a day, who let's say both weigh 8 stone 7lb at age 20, will both weigh exactly the same as each other at age 30 or 40?

I agree genetics could form part of it.

I eat a lot, lots of unhealthy food and four meals a day. I am a size 6/8. I can’t maintain a weight above 9 stone. All woman in my family are very slim, size 8 biggest size and we all eat.

Are you telling me that there is zero difference whatsoever between the way/speed two bodies burn calories, their frame size, etc

I think about this too in exercise classes. Jumping up and down if you are 8.5 stone is a lot less physical surely than if you are 11.5 stone.
Some floor exercises where you take your weight on your hands hurt my wrists - does the person running the class think of this. I must be burning more calories but then I spose I have more calories to burn!!

You really cannot change the Laws of Physics and essentially it really does come down to calories in Vs calories out. All the other reasons and excuses people have for being overweight play, at best, a very minimal role. For example far too many people assume they can eat 2000 k a day and not gain weight. In reality if you lead a very sedantary life then you probably only need 15-1600 calories per day to maintain your weight.

So do you think people who say they struggle to gain/maintain weight despite eating loads are actually lying or deluding themselves about how much they eat?

People who want to believe it is mostly genes and stay larger and at more risk of covid 19 can make that choice but it is a choice.

For virtually everyone if you eat less you will lose weight and that might then mean you are alive to see your children grow up.

Its the running and I bet she moves more.

Many studies re separated twins say it’s mostly genes nothing to do with staying larger.

It’s not a get out clause anyway. Nearly everyone has to not overeat to stay within healthy bmi anyway.

Still we are in an obesogenic society and sugar causes spikes and people eat more than they should.

Still think if studies say genes worth not discarding.

So do you think people who say they struggle to gain/maintain weight despite eating loads are actually lying or deluding themselves about how much they eat

Well they've made several TV programmes to test this theory and in just about all cases that was the case.

Channel 4 (or could have been 5) Secrets of thin people who 'ate all the time but never put weight on' didn't actually eat that much and moved around quite a lot when observed for 5 days.

BBC? Secret Eaters where they did the same for people 'who lived on salad but couldn't lose weight' but were without exception eating and drinking big portions, snacking and therefore consuming a lot of calories and literally either 'forgot' about half of what they were eating or had various reasons why the calories 'didn't count'.

@BarbaraofSeville that programme fascinated me!

Laws of physics apply to every human. Are you saying that if you were to starve for a month you would still look the same because of your genes?

moomin no
What I am saying is that two bodies may react differently depending on their genetic makeup. Bodies are different shapes. We know that some people are "gracile" and some are "robust". I am "robust". This means I have thick ankles, wide hips, a large bust and am "sturdy". Now obviously I can be fat or slim within that body shape, and if I am obese (as I am) it's because I am eating more fuel than I am expending.

So let's take your two people who are starved for a month. Both are 5 ft 6
One of them has fine ankles and wrists and was very slim as a teenager, at 7.5 stone
The other has always had cankles and larger breasts and was 91/2 stone at age 18, which was their lightest weight at their adult height.
At the start of the month they both weigh, say, 15 stone. They are both chained up as well as starving. Each gets 500 calories a day.
I don't think
A) that it is certain that both will lose the same amount of weight or
B) that their bodies will look the same at the same weight

Those of us of sturdy build beat ourselves up from puberty onwards in the quest for - in my case- slim legs, a small bust, a narrow pelvis. I will never look like a model no matter how skinny I am; my frame is different. It is a strong, sturdy frame but it will never be leggy and I will never be small busted. It shames us because at 9.5 stone as a teen I was "fat" compared to my 7 stone friends. I was not fat. For my frame I was very slim.