Why Doesn't Exercise Lead To Weight Loss?

antdude writes "The New York Times' Well blog reports that 'for some time, researchers have been finding that people who exercise don't necessarily lose weight.' A study published online in September 2009 in The British Journal of Sports Medicine was the latest to report apparently disappointing slimming results. In the study, 58 obese people completed 12 weeks of supervised aerobic training without changing their diets. The group lost an average of a little more than seven pounds, and many lost barely half that. How can that be?"

Comments

Hackers Diet FTW.

[RGreen]

The Hackers Diet makes it clear: Exercise just doesn't burn that many calories. You can lose weight just by eating less calories than you burn, no exercise required.

http://www.fourmilab.ch/hackdiet/www/hackdiet.html

Re:Hackers Diet FTW.

[cjfs]

Pretty much, not sure why this is a story. There's a little to be said for increasing muscle mass, and that's about all.

“It all comes down to energy balance,” or, as you might have guessed, calories in and calories out. People “are only burning 200 or 300 calories” in a typical 30-minute exercise session, Melanson points out. “You replace that with one bottle of Gatorade.”

In other news, water is wet and the sun is bright.

Re:Hackers Diet FTW.

[iocat]

Also, don't forget if you start an exercise regime, you're replacing fat with muscle at some level. Muscle weighs more. (But it looks better and takes up less space.)

Hacker's Diet is the best way to lose weight IMHO. It explains the basics (consumer less calories than you burn), and offers some good strategies for eating and exercise and geeky tools (inlcuding a web-based tracker) to aid in your descent into fitness. I lost close to 30 lbs on the "diet" and while it wasn't painless, it was pretty straightforward. I did gain a good amount back 2 years later when I quit smoking, however.

Re:Hackers Diet FTW.

[Daengbo]

Muscle mass is a really important point. I don't understand the obsession with weight. I went from 32% body fat to 15% body fat and weighed exactly the same. Guess which one of those left me feeling and looking better?

The researchers in the story ignored all the signs from the last ten years which point to strength training being the most important part of a regimen designed to reduce fat. When you do cardio (especially that slow, "fat-burning" cardio), you burn a few calories, and when you step off the machine, you're done. When you train for strength, you burn fewer calories, but your body spends the next twenty-four hours burning extra calories trying to repair the damage you've done. Doing anaerobic / aerobic intervals on a cardio machine has a similar effect, and when you put the two together, you really shed the fat.

You also need to watch your food intake so that your insulin levels stay as constant as possible. That means eating difficult-to-digest (generally "whole") foods instead of processed ones. Your body isn't just a black box. Eating some amount of calories in oatmeal and eating the same amount in breakfast cereal will have different results: your body works harder to digest the oatmeal so your metabolism is higher, resulting in lower total calories; the added fiber changes how your body digests the other food in your digestive system.

Cutting calories is a myth. In fact, while losing about 20kg of fat and putting on the same amount in muscle, I ate more than I had eaten before I started the program. I ate more. I exercised more. The ratio of calories coming in to those going out probably didn't change, but that increase in the total drove my body into overdrive and tricked it into ramping up my metabolism even further than the exercise amounted to.

Re:Hackers Diet FTW.

[pslam]

There's a lot to be said for exercise - it makes you healthier except in exceptional circumstances (like overdoing it, or if you have a heart condition).

Muscle mass is also a good way to lose weight long term. Short term, it weighs more than fat, so you get the surprising (to naive people) result that exercise can make you put weight ON if nothing else changes (and subconsciously you get more hungry due to the calorie burning).

Long term, muscle mass needs feeding. That's why your body gets rid of it if you don't use it - it's a waste of energy. You put muscle mass on, you burn calories whether you use it or not. Granted, it takes a lot. The best to focus on (so I'm told) is leg muscle, as they're already big and building them up is relatively easy (running/cycling/walking all do it).

But sure - exercise alone and diet alone isn't going to lose you weight. You need to do both.

Re:Hackers Diet FTW.

[iocat]

You can over-simplify calorie counting, but it isn't a myth. Eat less calories and you eventually weigh less. You may be less healthy, but I guarentee, you'll weigh less! I read some woman's magazine article one time that was like "Eating less calorines doesn't mean you lose weigh!" I was like, "really, tell that to someone starving to death..."

Getting 150 calories from a Twinkie certainly is less beneficial than 150 calories from oatmeal, for the exact reasons you describe, but they both give your body 150 calories to use (or store...).

Re:Hackers Diet FTW.

[Quothz]

The thing about exercise is, until you get to the point where you are pushing yourself to the limits you wont see drastic results. Most of the obese people I see in my gym spend half their time sitting around, or cycling on the lowest level while reading a magazine.

The folks in this study were under close supervision, exercising fairly intensely. It's fun to trot out your favorite lines about exercise but that's not really applicable here.

Re:Hackers Diet FTW.

[Mr. Freeman]

This is just one more fad diet. Your blog post reads like an advertisement full of bullshit pseudo-science. You know what's really happening? YOU'RE STARVING YOURSELF. Call it whatever the fuck you want, but this isn't a diet, it's just not eating.

As for your claims of weight loss: of course it works, not eating will cause you to loose weight. It also causes other health problems. I suggest you talk to your doctor rather than whatever unlicensed moron (a.k.a "diet expert") looked up what happens when your body goes into starvation (one of those things is ketosis) and called it a "health plan".

Re:Hackers Diet FTW.

[stjobe]

Course, this may be more of a girl thing.

No, no, it's absolutely not a "girl thing". There's plenty of guys that are embarrased about how they look in a gym outfit or in a pair of swimming trunks, and therefore do not go to the gym or the pool.

Exercising next to all the ripped guys by the mirrors is intimidating for us guys as well.

Re:Hackers Diet FTW.

[h4rm0ny]

The majority of fat gain as you get older, is due to deterioration of muscle mass leading to a lower resting metabolic rate. Having muscle helps keep the weight off. As well as reduces the risk if impact injuries and helps actually doing things.

Re:Hackers Diet FTW.

[realityimpaired]

Eating some amount of calories in oatmeal and eating the same amount in breakfast cereal will have different results: your body works harder to digest the oatmeal so your metabolism is higher, resulting in lower total calories; the added fiber changes how your body digests the other food in your digestive system.

I think this is the point, more than your point about muscle mass (though that's a valid point, too...). TFA says that these people did supervised cardio without changing their diets. If your body requires 2500 caloreis per day to maintain a healthy weight, and you're consuming 4000, then burning an extra 500 calories in cardio isn't going to make a difference.

You're right that with a high muscle mass, it's possible to be in the "morbidly obese" category while not actually being fat or unhealthy. Professional athletes are frequently in that category, for example. But most people don't have such large amounts of muscle, and when they tip the scales at 250lbs, it's because they have much more body fat than they should. Doctors tell them thatt they should lose weight, not because they necessarily need to lose the weight, but because it's easier than testing their body composition and telling them that they have too much fat in their body. But the doctor is supposed to apply some common sense... if a male is tipping the scales at 250lbs, but wearing a 34" waist, then even though he's in the "obese" category, he's obviously not actually obese.

If you want to lose body fat, you need to look at the big picture. It's fine and well for you to say that you ate more in exchanging 20kg of fat for muscle... but I can tell you first-hand that it doesn't work that way for females. We have to put in twice as much work to build muscles due to lower testosterone levels, and people tend to look at you weird if you're muscle-bound. Having muscle tone, and adequate strength is much better than building muscle mass, thanks to societal pressures... and that comes from cardio. But the only way you're going to lose weight through cardio is by not consuming way more calories than you need. It's well and good that you're in the cardio zone, and burning fat calories (I run 6 miles a day, and usually finish under 45 minutes, for example), but if you're still consuming way more calories than your body actually needs (including the extra 500-700 you'd burn from that level of cardio workout), then you're not going to lose weight. It's becoming a tired mantra, but it's no less true: eating less and exercise is the only way to do it.

Re:Hackers Diet FTW.

[h4rm0ny]

I don't know what others have experienced, but I have met a number of "iron pumpers" who feel compelled to tell me I'm doing an exercise wrong even when I'm not.

It's quite possible that they are trying to be friendly / helpful. If you're doing free weights, it's even quite possible that you are doing the exercise wrong whether you think you are or not. Often it's hard to see what you're doing incorrectly yourself. That's one of the reasons people watch themselves in the mirror when they do weights - they can see if their back is swinging when they do a barbell biceps curl or if its straight when they do a squat. You can always just have a conversation about it with whoever has offered the advice. Mistaken or not (and if they're obviously an experienced "iron pumper" why do assume they are incorrect?), they're offering help.

Re:Hackers Diet FTW.

[Cinderbunny]

Having recently lived in Tokyo gave me a new perspective. I always struggled with losing weight in North America, but once I moved to Japan the weight came off very quickly. What I think were the main contributing factors: 1) I walked everywhere, walked upstairs/downstairs at stations and work. 2) Small portions - your stomach gets used to ever-expanding portions. Portion control is unfortunately necessary. Miso soup is amazing for expanding rice in your stomach and making you feel very full for incredible low number of calories. 3) Good calories - There is, of course, processed foods in Japan, just not as in-your-face. Most grocery stores are super small and in your local market. Some only carry fresh produce and fish and meat. I cooked every meal in Japan. I did so in Canada too, the difference was that a lot of Japanese dishes are boiled / steamed instead of fried. I told one of my clients about Eggplant Parmesan and he looked nauseated. I picked up a Japanese cookbook and learned that they lightly boil/steam their eggplant. 4) I've heard that the more sugar you eat, the less flavor you can taste. I cut out all sugar while in Japan (except for alcoholic drinks - yum). For me, it was true that I could really taste food again. It's a hard sensation to describe something you hadn't been sensing before but were all of a sudden attune to. I have a feeling that this extra sugar leads to MORE extra sugar to taste said sugar and also to increased levels of 'flavor' in dishes. I've heard that the Japanese like their flavors subtle. This is definitely the experience I had in downtown Tokyo. Anyway, it worked for me - I went from 135 lbs down to 112 lbs. Now, back in Canada, I notice advertisements for HUGE portions of everything. Last anecdote, I got a Tall latte from the Starbucks in Shinagawa station and while walking to work I ran into a client who commented on my coffee, laughing, saying I had a big appetite. Considering a "Tall" is no big thing here, I both blushed and was taken aback. After that I really reconsidered if I needed so many fat and calories in my diet - don't we always upsize only because it's just a better deal, not because we actually want more food? Just my thoughts!

Re:Hackers Diet FTW.

[Bigbutt]

As someone who fights with this, it's not a full feeling that's the problem. Feeling full doesn't keep me from wanting something like ice cream or chips. Desire is more of a problem than feeling full. I can eat to satisfaction and not be full or even eat to bursting but see ice cream or smell ribs or bacon and immediately want some. It takes thought and discipline. It's why I can't leave a bag of chips close by and eat them. I'll mindlessly eat them while programming until I realize I've eaten a whole bag of chips and not remembered doing so.

[John]

Re:Hackers Diet FTW.

[uglyduckling]

Sure, I know where you're coming from, but surely feeling full would help? I work night shifts a lot at a hospital, and for months I was running on sugar buzz - every time I felt tired I bought something from the vending machine to wake me up for 30 minutes. I've been overweight almost all my life - not massively - but enough to always feel self-conscious and not want to go to the beach etc.

In the end I realised that I had to do something (or else go shopping as all my clothes were getting too tight). I decided I really wanted to do something, made a plan (which as I said was along the lines of the Hacker Diet) and also told all my friends. The last bit really helped - whenever they saw me with food (other than a meal) or on a webcam or whatever I'd feel guilty and get rid of it.

The other thing is, I found that if I cut out all of the high calorie snack foods, there's no reason at all that I can't enjoy a good meal whatever the calorie content. Since I started trying to loose weight, I've still had a takeout meal about once I week, I still eat whatever I want at a restaurant. If, like me, you eat loads of snacks, then you're actually in quite a good position to cut those out and still enjoy a decent meal when you want to. The other week I went out for a meal with my wife and sat and watched her eat cheesecake at the end - I didn't fancy any so I didn't have it - which would have been impossible for me six months ago.

Please don't think I'm being egotistical - I'm rubbish at being self-disciplined - but I just decided that I really wanted to feel OK about myself in this regard, not to suddenly be a male model but to get it under control. It is possible, harder for some than for others, but if you want it then you can do it. I think the Hacker Diet is great because it's not about a two-month crash but a long-term plan.

How can that be?

[ColdWetDog]

Well, a 3.5 to 7 pound weight loss over 12 weeks isn't such a bad result. You can't just diet, you have to change lifestyle. TFA seemed kind of whiny, like one expects to magically melt the pounds off if you run around a while. Even moderate physical activity only burns a couple of hundred calories per hour - that's one brownie.

Then there is the issue of converting fat to muscle (which weighs more) and the fact that people in general don't exercise as much as they think they do. For most people, weight control is hard, it's basically a lifetime commitment to minimizing calories and maximizing physical work.

The world continues to deteriorate

Give up.

Re:How can that be?

[DeadDecoy]

I think we as a culture are too used to being sold quick weight loss 'solutions'. True fitness, as you say, comes from a change in lifestyle, where one should be exercising not for 12 weeks but for several years to be in a healthy state. Unless you go through some painful and hellish training regimen, getting fit doesn't happen quick.

Re:How can that be?

[klenwell]

Or go with the flow. As TFA points out, whether you lose weight or not, work out a few hours a week and you're healthier.

My own experience confirms this. All my life, I was too thin. Then I left school and got an office job about 5 years ago. All the sudden I'm not having a problem keeping on the pounds. I never got noticeably overweight but I was getting a little soft around the center. Signed up for a 24-hour fitness membership a couple years ago and was surprised that my weight continued to inch up.

Finally, earlier this year, I changed up my workout. More cardio, less weightlifting. Also went from around 4 1.5-hour workouts a week to 6. I just treat it like my job. As soon as I get off work, it's off to the gym for two hours (which has the advantage of waiting out traffic.) I also made some adjustments to my diet. Less fast food. Replaced cola with coffee (caffeine) or lemonade (sweet). And though my sweet tooth is as sweet as ever, I am more conscious about eating that extra snack or the dessert that was left in the break room, and consequently, I probably eat a few less calories on average.

But my real secret weapon: the Nintendo DS. I needed something to distract me from the drudgery of the stairmaster and lifecycle and I can only gawk at the girls for so long. I don't play video games otherwise, so I look forward to an hour or so playing with the DS while I sweat. Turned-based games like Advanced Wars (or chess) are perfect for the stairmaster.

The result: for the last 6 months, I've been shedding a pound or so every 2 weeks, about the same as the study. A few months of that will add up.

Re:How can that be?

[Tablizer]

That's the problem with exercise and diet: it's like a job that pays $1 per hour: a lot of work and sacrifice for tiny results. Diet food tastes like shit. The box it comes in is tastier than the contents in my opinion. Repeated studies show that even fairly intense diet and exercise result in only about a 15 pound reduction over the longer run. People then think, "Why should I bust my ass chasing that 15 lbs? I'm still overweight. Fuck it, I want a donut!"

Re:How can that be?

[KaiLoi]

That's because you shouldn't eat diet food.. It's pre-packaged crap for people who are too lazy to learn how to cook properly for themselves.

Shortcuts are never tasty

I highly recommend getting a book called "The Okinawan Program" which is a study of some of the healthiest people on the planet and their diet and lifestyle.

It contains some delicious healthy recipes that leave you feeling very full, are exotic and tasty as hell and yet keep you below that horrific calorie level needed for weight loss

To take what someone said earlier and expand on it. "Stop eating so much fatty, and learn to cook!"

Re:How can that be?

[Waccoon]

The longer you do without junk food, the less you crave it. Real food tastes much better after you've given up donuts, burgers, and MSG. Rather than a $1/hr job, think of a diet as starting college as a broke student. It takes a while to graduate.

It's not that simple

[Rix]

Your body is not a simple machine. How much you eat impacts how much you use; simply cutting calorie intake will just cause your resting metabolism to drop. Worse, you might start metabolizing muscle.

Re:It's not that simple

[WarwickRyan]

Yup, burning muscle sucks.

I've had two major weight loss periods in my life:

First was from 130 kilos down to 80 kilos. I did this through eating 1500 kcal per day exclusing green veggies AND doing intensive cardio on the treadmill five times a week, hitting 500kcal on the calorie counter each time.

Now I did drop a load of weight, but a good portion of that was muscle. I did regular max-lift tests on biceps and my legs, and over the course of my weight loss the weights I could lift more than halved.

Second major weight loss is from 108kg to 94kg. It's still ongoing, with the final goal being 80kg again. This time I didn't want to loose muscle, so joined the local gym and took professional advise. This resulted in a combination of diet and mixed training plan being made. For the food, my intake drops to 1500-1700 kcal per day for six days a week, split into 6 meals. For the training, I do 3 weight sessions a week (upper body, lower body, upper body, lower body etc etc), 3 cardio sessions doing interval training and 1 session which combines cardio and weights focusing on endurance.

The result? At the half way point I'm stronger than when I started. I've increase my weights by about 30% since the start (about 4 months now). I'm also getting some muscle definition. Weight loss is now steady - it's slower than my first but the actual inches being lost around my waist more than the last time.

So through my experience you're right. Cardio training combined with diet for weightloss is really counter productive. Adding weights in there is clearly the way to go.

Re:It's not that simple

[Davorian]

There is probably less muscle loss than you thought. Intramuscular fat is a major player in muscular strength, and if you're losing fat you will lose significant amounts of strength entirely without having to break down actual muscle.

Unfortunately not

[Rix]

Even if you're a tub of lard, the body reduce your metabolism and metabolize unused muscle mass before using fat reserves.

McDonald's hasn't been around long enough to have an evolutionary impact. Starvation has.

Re:Unfortunately not

[drgonzo59]

That is not true. In starvation mode the body will use the fat first and then the muscle. A body without muscle and all fat is useless. In other words, look at the victims of famine, they usually can still move even though they are emaciated, _but_ they are not fat. If muscle would burn first, they would just end up as sacks of lard + bones completely unable to move. If such an organism ever evolved it probably, it would have quickly died out out as it would not be very efficient.

Re:Unfortunately not

[h4rm0ny]

That is complete bullshit.

No it isn't and you are posting potentially harmful information. When your body goes past a particular point of calorie reduction, it starts metabolising both its fat reserves and underused muscle. Your body doesn't know how long the "famine" will last. If it burned away all the fat first, then at the end of that process it would have a great load of expensive to maintain muscle for little benefit. If you lose your job, you don't wait until you've used up all your savings (fat) before you start cutting down on unnecessary spending (muscle that isn't being used a lot for exercise). Instead, you are more careful with your savings and you cut back on spending. Do you see?

If you severely cut back on calorie intake (around 15% or more below what you need for maintenance) and you're not offsetting muscle loss with exercise, you lose muscle along with the fat.

The rest of your information is hopelessly out of context. Don't advise people on health matters when you don't know what you're talking about. It's not like talking misinformed crap about Linux or Microsoft. It can harm people's health.

Re:Simple formula

[shutdown -p now]

In fact, it's quite possible to starve to death with excess body fat still in place, simply because your metabolism slows too much and available energy stores aren't being depleted.

I was always under impression that fat is stored in body primarily to be burned when no food is available, as a survival mechanism; and secondarily, to provide thermal insulation. What you describe is essentially in direct contradiction to that. Can you provide any references to your claim (something explaining how such an arrangement could have evolved would also be interesting)?

Density

[Mathinker]

It's called "density", you know, dense...

Oh, wait, maybe you're already quite familiar with it...

Conservation of Energy

[otter42]

I know a lot of people are going to talk about CoE. After all, that's the driving equation here. It is absolutely correct, but can we not glean more insight into the problem?

IWAHTE (I Was A Heat Transfer Engineer), so my guess is that what's going on is that people spend the vast majority of their calories maintaining body temperature. If you eat less, your body's first reaction might well be to reduce skin temperature, maintaining core temperature. This theory links the fact that women eat less then men by 20% with the observation that women are complain about being cold earlier than men. Less calories burnt to keep skin temperature high.

In the case of someone who is overweight, they have an additional layer of blubber (yes, basement /. denizens, you are coated in blubber) that insulates them and maintains their core temperature for free. Maybe there's a hysteresis? First the body weight comes down, then the body learns it can waste excess heat maintaining skin temperature, and then, and only then, the body is free to consume additional calories.

Now, I don't do human anatomy, so a doctor would have to chime in and confirm just how much of the body's caloric consumption is lost to heat, vs. other bodily functions.

A personal example: on an average day, I eat some 3500 calories. But I am athletic, and only weigh 70, so this is a "good" 3500 kCal. What I notice is that my skin temperature is always warm, especially compared to women. In fact, I am very comfortable when the temperature is around 15deg inside. I go outside on a 5deg day in nothing more than a sweater and a top hat. I routinely mock my friends who wear a sweater, coat, and scarf when I'm sitting around in short sleeves. Certainly, my body is horribly inefficient, and if society falls in some sort of catastrophe, I will certainly be one of the first to starve (if my 20/800 eyesight doesn't make me walk off a cliff first). However, in a society that has mass amounts of overconsumption, it seems to fit me just fine.

A second personal example: I dated a German doctor who as a 16-year-old doing a year-abroad in Minnesota, had been anorexic. After she came back, she put on a lot of weight: obviously her body reacting to the extreme abuse she had given it. Now as a 25-year-old, she was in the Bundeswehr (German army), and this girl could RUN. She ran marathons. She ran 2 hours with 25kg of weight attached to her. And yet she was always, always overweight by 8kg or so vs. her pre-American anorexia bout. Not a lot, but she was... pudgy. She'd been to doctors, etc, and could do nothing to get her weight down. I lived with her for a while, I can guarantee she ate nothing but healthy food, and only somewhere around 1600-1800kCal/day. However, she liked her rooms warm.

So I am less physically active, yet consume twice as much. The only thing that can explain this is that physical activity just doesn't use that many calories, not compared to maintaing body temperature. Since I go outside without a coat, I burn more calories than she does to maintain the same core temperature.

My two cents, but I certainly welcome other /.er ideas, though.

My diet/exercise experiences

[chrisG23]

I was once obese, 300 lbs. I lost 100 pounds over an 18 month period by going on a low carb diet, with no significant extra exercise. My thoughts on that are that if your body is capable of going into ketosis (the mode where it gears up for using fat as energy, both from food in the stomach and fat stores throughout the body) then it is effective for weight reduction. Also, eating a low carb diet got very boring for me, and I found myself eating less because of this (was never hungry or starving myself though). This of course is different for everyone.

Next major body change was when I joined the Navy. I went into boot camp weighing 199, I got down 8 weeks later weighing 199 but with vastly less body fat. My physical structure changed significantly. I started off not eating to much, but ending up consuming pretty large amounts of calories (and drinking tons of water, that is very much forced on new recruits to avoid dehydration problems which are very common when you are exercising in one form or another for most of the day.) Most of the people in my division did not lose weight, some gained a few pounds, all were in vastly improved physical condition. Not big body builder type musles, but lean endurance muscles.

The best method of weight control/weight loss I know is to not eat until I feel full. If I am hungry I will eat until the hunger stops, and then wait 15 to 30 minutes. Sometimes I find there is more room, usually I find that I am full. It seems to take food some time to settle in and for my stomach to give the feedback to the brain that it is doing alright. The stomach is actually a pretty small organ and the digestive system seems to operate best when working on small loads. Full loads both have the effect of stretching and enlarging the stomach (thus making it more difficult to feel full) and diverting energy to digestion (alot of energy is consumed for digestion, thats why people go on health fasts, to give the rest of the body a period of time where the body's energy can be continuously applied to other systems for repair and maintenance. Thats the idea anyway) that could be used for other things, like keeping one alert and full of energy and providing for the immune system to do its job.

My $0.02

12 weeks?

[Dunbal]

That's your problem right there. Let's see:

      Fat is a long term storage form of energy. Everything (proteins, glucose) can be converted to fat, but fat cannot be converted back to glucose (unless you count the lone glycerol molecule that holds the 3 fatty acids together on the triglyceride). It's NOT a reverse reaction. Thus the problems begin. It's easy to make fat, and hard to get rid of it.

      So how is exercise supposed to get rid of fat then? Well, fat CAN be converted to acetyl-COA and shoved into the Krebs cycle. Only the Krebs cycle is an AEROBIC process and takes place in the mitochondria, not in the cytoplasm of the cells. Aha! Problem #2. Sedentary people have fewer mitochondria than athletic people. Therefore their ability to "burn" fat as acetyl-CoA is limited. An athlete can burn fat just as efficiently as glucose, the only difference being he'll lose out on the couple ATP from glycolysis.

      So you need mitochondria, in quantity, to burn up acetyl-CoA and therefore fat. If you don't get rid of the acetyl-CoA somehow, the whole catabolic process starts backing up. How do you obtain mitochondria? Increased exercise - over a sustained period. 12 weeks is hardly enough to increase the number of mitochondria in your muscle cells, much less expect them to burn through a dozens of kilos of fat. But the title of this article is misleading - according to the study the cited article is based on -

Mean reduction in body weight was -3.3 ±3.63kg (P less than 0.01). However, 26 of the 58 participants failed to attain the predicted weight loss estimated from individuals' exercise-induced energy expenditure. Their mean weight loss was only -0.9 ±1.8kg (P less than 0.01). Despite attaining lower than predicted weight reduction, these individuals experienced significant increases in aerobic capacity (6.3 ±6.0ml.kg-1.min-1; P less than 0.01), decreased systolic (-6.00 ±11.5mmHg; P less than 0.05) and diastolic blood pressure (-3.9 ±5.8mmHg; P less than 0.01), waist circumference (-3.7 ±2.7cm; P less than 0.01) and resting heart rate (-4.8±8.9bpm, p less than 0.001). In addition, these individuals experienced an acute exercise-induced increase in positive mood.

      So they ALL lost weight. Only some (probably cheated on their diets/lied about their original diet) lost LESS weight than others. Continuing the exercise for more than 12 weeks would probably have caused further reduction in weight. I don't know HOW the submitter can turn that into "Why Doesn't Exercise Lead To Weight Loss?". Oh yeah, but this is slashdot- news for nerds. This site should be renamed to "Slashdot - news for trolls: engage critical thinking now".

Another thing lots of people don't consider

[TheLink]

Even more people (including researchers) don't seem to think about the energy excreted in the feces (or other ways).

I hardly ever see any mention of it in studies related to weight loss, diet etc.

Go check out how many researchers actually take samples and work out how much a subject is excreting.

Then there's was also a study which showed that mice in a bacteria free environment could eat a lot and not put on weight.

See: http://www.npr.org/templates/story/story.php?storyId=95900616

And another which had the bacteria free mice getting gut bacteria from obese mice and ending up fatter than if they got gut bacteria from skinny mice.

http://www.npr.org/templates/story/story.php?storyId=6654607

Based on these, it should not be a surprise that some people will actually find it hard to lose weight despite eating and exercising the same as skinny people. Of course, your diet also affects your gut bacteria populations. I bet consuming lots of "sugar water" isn't going to help breed gut bacteria that makes it easier for you to be skinny.

Re:Telling that to someone starving to death

[ThatMegathronDude]

That stuffed belly look is the end-game of starvation, don't be fooled. That woman with the obese look isn't obese, her body has started breaking down connective tissues which leads to sagging skin and distended bellies.