Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

When somebody loses weight, where does the fat go?

bmj.com

Post reply on HN
Print view View original

171–180 of 241 posts

Re: When somebody loses weight, where does the fat go?

#171

Post by bitexploder »

StevePerkins wrote: post #79
beardbandit wrote: post #49

Earlier quoted context omitted.

"I can't help but groan at some of the "obvious" health and weight loss platitudes that get smugly thrown around." On the flip side, the people that are told this are the ones that are annoyingly attempting to maintain their bad eating habits while just adding exercise, or adding fab foods, or anything really to delude themselves into thinking they can continue to eat the same way.

I have never in my life met someone who has the physical and mental discipline to exercise regularly, yet also still sits around eating candy and pizza the other 23-hours of the day. MAYBE if you're still in school, or a new grad in your 20's, you might know people who are physically active but also like to drink heavy / party. But by the time you're 30 or so, exercise and decent eating habits tend to correlate one w…

I have had periods where my diet totally relapsed but my exercise never did. That is why I think (most) people need mental, exercise, and diet based strategies to lose weight. If you only use diet and that gets sketchy for a while (life stress, whatever the reason...) then your chance of relapse and weight gain are much higher. When just one piece of your strategy falls away if you still have a few other legs holding it all up it will probably stay standing.

Plus I have met distance runners with ridiculous diets. Some of them run 50 miles a week just so they can eat a pint of ice cream every week and pizza multiple times per week. It happens, but those are always at the extremes. A balanced approach is needed for most mortals.

People will justify their beliefs in a whole bunch of different ways. Until someone has actually lived it and dropped 40+ lbs and kept it off for years I immediately down grade whatever advice they are giving as they are simply less credible (unless they are well versed on the actual science and literature of the topic, in which case they likely never gained excess weight to begin with or fall into that category of someone who has lost weight and kept it off).

The number of people I have met or know personally who diet it all off with no exercise and are convinced how right they are "I lost 100 lbs!" only to balloon back to their start weight or close to it is ... a lot.

Re: When somebody loses weight, where does the fat go?

#172

Post by _0w8t »

adekok wrote: post #126
leshow wrote: post #48

Earlier quoted context omitted.

I'd suspect the more exercise you do the more that number moves up, you'd be breathing harder. I'd hesitate to try and put a 'hard limit' on anything like this.

It's pretty difficult to double that number. Can you really double your metabolism without ill effect? Or without massively changing your lifestyle? The normal expectation is maybe 10-25% change. Any more than than would require things likes 8 hours of exercise per day.

A colleague who was into serious mountain climbing said that at 5km it was not enough to eat like 5000 calories per day to maintain weight. He even on purpose gained weight before his trips, and still returned leaner despite eating a lot.

Re: When somebody loses weight, where does the fat go?

#174

Post by makemoniesonlin »

adekok wrote: post #38
mikeash wrote: post #4

For anyone coming straight to the comments looking for an answer to the question: it turns into CO2 (and a bit of water) and you breathe it out. When you realize that you have to breathe out all the weight you lose, I think it gives you a bigger appreciation for how difficult weight loss can be.

2 pounds a day. That's how much CO2 you breath out, and the hard limit for weight loss. You can lose more than that, (see boxers before a weigh-in), but that's all water loss, and is temporary. And, with a strong likelihood of death.

What if someone has a deficit of over 7,000 calories/day for an extended period of time (suppose they eat 3k calories and bike for 14 hours/day)?

Re: When somebody loses weight, where does the fat go?

#176

Post by bitexploder »

pbhjpbhj wrote: post #163
bitexploder wrote: post #157

Earlier quoted context omitted.

Running at a moderate pace for 45 minutes is an easy 90-110kcal / mile depending on your weight. Running is a double edged sword on appetite. It tends to shut down your gut for a while, making you less hungry for a period after the workout. But, people tend to misjudge how much they burn on shorter workouts or runs. Often people only need 2 or 3 habit changes to create a long term deficit. Example: run a few times a…

>Running at a moderate pace // If you're obese you will knacker your knees. Swimming is better, but be careful to exercise complementary muscle groups too.

You can walk. If you are at 50 + lbs of weight and haven't run at all fast walking will put you in the same cardio zone as running for a lighter weight runner. The math of calorie loss as it goes with running is the simple equation of how much weight are you moving and what cardio zone is your body operating in to move that weight. If you can hit low aerobic fast walking (most non runners can do that easily), just do that.

Beyond that I am not sure about how running impacts the joints of heavily overweight people. I would advise a very slow and conservative ramp of up mileage. I think as long as the body is given time to adjust it can do so with minimal risk of serious injury (even if you are running). The problem with running is your aerobic capacity will likely outstrip the rest of your bodies ability to absorb punishment. This is why so many "I am going to run a Marthon, but have no prior running experience" people end up injured and then wander about telling people how bad running is for your joints, etc.

(https://www.runnersworld.com/general-interest/runners-have-m...). Could just be a self reporting bias, but it is interesting. Several studies over the years have looked at life long runners knees and they seem to be fine compared to a non runners.

I didn't even go into some of those "soft" benefits of regular exercise, such as the mental boost it gives (which seems like it would support weight loss), along with the obligatory lymph system circulation which is likely to improve immune health and help with waste cycling. As long as someone isn't overtraining, that is :)

Re: When somebody loses weight, where does the fat go?

#177

Post by watwut »

jedrek wrote: post #85
StevePerkins wrote: post #37

Earlier quoted context omitted.

I can't help but groan at some of the "obvious" health and weight loss platitudes that get smugly thrown around. " Calories in, calories out! " " You can't outrun a bad diet! " " Weight is lost in the kitchen! " Sure, things ultimately boil down to intake-vs-expenditure. However, it IS more complicated than that in practice . As software developers, we complain when management makes decisions based on inadequate or p…

I think you're misreading the function of those slogans. First off, they're hardly "obvious" when you account for the overwhelming FUD around nutrition anybody who's tried to lose weight. And you get it from everybody: your Mom, magazines, movies, the news, pop sci articles, the government, etc. But more importantly, those things are TRUE. Anybody with significant weight to lose will not be able to out-exercise a bad…

The worst thing you can do is to focus on calories only. That is the worst advice out there and you get it from everywhere.

YoYo effect guaranteed, cravings guaranteed, lesser ability to focus at work guaranteed and so on and so forth. And you will be miserable and won't keep it long term.

You don't just loose fat when you exercise, you build muscles, your cardio system is getting better etc etc. The way people here talk about it all sounds as if they would be putting on makeup - there is more to health and performance (including mental) then just how quick you lost few kilo.

Re: When somebody loses weight, where does the fat go?

#178

Post by [deleted] »

jedrek wrote: post #85
StevePerkins wrote: post #37

Earlier quoted context omitted.

I can't help but groan at some of the "obvious" health and weight loss platitudes that get smugly thrown around. " Calories in, calories out! " " You can't outrun a bad diet! " " Weight is lost in the kitchen! " Sure, things ultimately boil down to intake-vs-expenditure. However, it IS more complicated than that in practice . As software developers, we complain when management makes decisions based on inadequate or p…

I think you're misreading the function of those slogans. First off, they're hardly "obvious" when you account for the overwhelming FUD around nutrition anybody who's tried to lose weight. And you get it from everybody: your Mom, magazines, movies, the news, pop sci articles, the government, etc. But more importantly, those things are TRUE. Anybody with significant weight to lose will not be able to out-exercise a bad…

[deleted]

Re: When somebody loses weight, where does the fat go?

#179

Post by _0w8t »

mtreis86 wrote: post #140
adekok wrote: post #126

Earlier quoted context omitted.

It's pretty difficult to double that number. Can you really double your metabolism without ill effect? Or without massively changing your lifestyle? The normal expectation is maybe 10-25% change. Any more than than would require things likes 8 hours of exercise per day.

5-6000 Calories is normal for an 8 work hour shift at -10c. https://academic.oup.com/jcem/article/99/12/E2772/2833739

This is very interesting paper, but is it a right one? I do not see any mentioning of working in such conditions nor 5-6000 calories per day.

Re: When somebody loses weight, where does the fat go?

#180

Post by darrenf »

ksec wrote: post #136
darrenf wrote: post #94

Earlier quoted context omitted.

I've lost 16kg this year, which I attribute to 3 things: 1. being fairly strict with calorie intake - though I have gone over my limit a whole bunch of times 2. upping my running game - 80km+ most months 3. being diagnosed asthmatic (after 40 years of merely "you've got shitty lungs, sorry") and prescribed a morning+night inhaler Dieting isn't new to me, I've been a fat bastard all my adult life. Previous attempts at…

asthmatic - how did you get it diagnosed after 40 years? just wondering, pure coincidence ?

I had brochitis as a child, which by adolescence and several years of treatment with inhaled steroids seemingly just settled into an adulthood of "I wheeze and my lungs just don't work well". Never saw anyone about it, just figured it was my lot.

In 2012 I had a really bad lung infection that resulted in an asthma-like attack and ambulance taking me to hospital in the middle of the night. Months of tests resulted in them diagnosing me with Small Airways Disease, which my layman brain recalls as meaning "your big pipes are fine, but your thousands of small pipes are terrible". Not much to be done medically, but they were astonished that I had at that point run a couple of half marathons and essentially prescribed "keep running!". My readings when keeping a peak flow diary were "lungs of an 80-85yo female", rather than the 35-40yo male I was. That's pretty bad: https://patient.azureedge.net/media/Default/_Profiles/4e4362...

At the end of 2016 I had reason to visit my surgery's nurse about another matter and she said "can I hear a wheeze?". A few tests later, and (apparently) some kind of threshold for one of the measurements has changed in the last few years, and hey presto: I'm officially asthmatic.

Post reply on HN