Why Doesn't Exercise Lead To Weight Loss? 978
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?"
I'm currently losing 2-3 kg/month (Score:3, Informative)
And I've been doing so for the last 6 months. I've been keeping track of what I eat in a database, and I can tell you that if you're not, you're constantly changing your diet. Eating till you're full will have drastically different nutritional values, and you're just not equipped to gauge that.
I've also been exercising. I wasn't losing weight until I did both.
Re:How can that be? (Score:2, Informative)
Fat can not be converted to muscle. It can be stored or burned. That's it.
You can just diet. Take in fewer calories than you burn, and you will lose weight.
It's not that simple (Score:5, Informative)
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.
No (Score:4, Informative)
If you just cut your calorie intake, your body will adjust. You have to exercise so you're body doesn't decide that your muscle mass is more expendable than your energy reserves (fat).
Re:But it's all physics? *snark* (Score:4, Informative)
Also, in neither of the studies do they actually monitor the food intake. So while it says that the diet didn't change, the subjects very well could have eaten more.
Basically if you want to lose weight, you're going to have to do something with your diet. This is something that was common knowledge 25 years ago, but somehow we seem to have forgotten it.
Re:Hackers Diet FTW. (Score:5, Informative)
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.
1/2 cal per mile per pound is lost walking/running (Score:3, Informative)
well - actually about 0.6 or so, and since a pound of fat is about 3500 kcal of energy, an average sized person (150 lbs) would need to run/walk 38 miles to burn a pound of fat - or I could just eat half portions for 3 days.
The study says they just lost a little weight, not none at all.
Re:Hackers Diet FTW. (Score:5, Informative)
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:But it's all physics? *snark* (Score:1, Informative)
Spoken like a true fatty.
Re:Hackers Diet FTW. (Score:4, Informative)
Good point. Also some studies have shown that those who exercise don't lose as much weight because they perceive exercise as this great calorie burning activity, then they go and eat more to reward themselves for the 'great job' they've done.
While it's fun to trot out pet peeves, the study in this article controlled for that.
Re:Hackers Diet FTW. (Score:5, Informative)
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:Unfortunately not (Score:1, Informative)
> and metabolize unused muscle mass before using fat reserves.
That is exactly why one need to exercise. So there would be no unused muscle mass.
Re:It's not that simple (Score:5, Informative)
Re:Hackers Diet FTW. (Score:3, Informative)
Re:Hackers Diet FTW. (Score:4, Informative)
I agree with the comment about muscle density though. I stopped weight training when I graduated from high school (I took weight training for my mandatory phys ed credits). I weight the same now as I did then, but I look a lot fatter because I haven't been to the gym in forever.
I remember that I was quite fat before I started weight training. I was very surprised by the gain I saw when I started. 2-3 times per week of 50 mins. of weight training and within a month I already looked noticeably more fit. No amount of running around in phys ed classes has ever shown such an improvement.
That said, some people much prefer running to weight lifting. Personally, I hate running and I have thus hated every single phys ed class I have ever taken with the exception being weight training. But there are other people that run to work, run from work, run for fun on the weekend and they are some of the most in-shape people I know. It really depends on what kind of person you are. There's no one universal solution to weight loss.
Re:Hackers Diet FTW. (Score:2, Informative)
Re:Unfortunately not (Score:4, Informative)
The body is quite complicated. It's not like it burns just one thing at a time. The proportion of fat/protein/carbs burned depends on a lot of factors. If you look at starving people, you will also note that they are not over muscled. Experienced body builders *will* reduce their calorie intake to get down to 1 or 2 percent body fat, but they have a lot of tricks to avoid burning too much protein (thereby cutting down their hard won muscle).
A lot of people want to lose weight in order to look good. I would hazard to say that they are less worried about health issues than looking good (thus the crazy diets people go on). Muscle is *really* difficult to put on. Fat is relatively easy to lose. Putting on a pound of muscle means going to the gym and lifting weights for a good 10-30 hours (depending on a lot of factors). Losing a pound of fat is as easy is avoiding drinking that can of coke every day for 25 days. You should be careful of crash diets that will end up burning muscle.
Without going into details, aerobic exercise is a good way to protect your muscle mass when losing weight (the body shifts to burning a larger percentage of fat directly when doing aerobic exercise). Running 3 miles a day will burn about 400 calories each day. If you run 6 days a week that will be about 3/4 of a pound a week. But you have to be
careful of diet since you will be more hungry.
Unless you are crazy into running (which is unlikely if you are overweight), anything more will have to be done with diet. But you really do have to be careful of losing muscle. Especially people who can't exercise very much (due to lack of fitness, or ill health) really need to be realistic about what they can accomplish in a short time.
Lately I let myself get a bit overweight. But I lost about 30 lbs in 3 months. Unfortunately I now realize that nearly 5 lbs of that was muscle. I was too aggressive in shedding the weight. Now I'll have a fun time trying to get it back (especially since I'm over 40 now... sigh...)
Re:Hackers Diet FTW. (Score:3, Informative)
IMO the whole "fat (duh)" thing is a myth - I'm not a doctor or anything but from what I've read so far, the amount of fat you can store is affected by the amount of carbs you eat at the same time. And I've been eating a relatively high fat diet for a couple of months now, with no sign of it all being dumped directly into my fat reserves. There was a whole lot of bull bandied about about fat by the US govt in the second half of the 20th century, and anyone who questions it is treated like a lunatic. Pretty much the same type of thinking that starts and perpetuates religions is happening with the whole "fat makes you fat/is bad for you" thing. Fried fats aren't very good for you, but fat in general is fine, and doesn't make you fat. Most people however just run off of carbs/blood sugar spikes and keep ending up "hungry" every few hours because they are not used to using fat for energy. If you're not making use of your fat reserves, of course you are going to get fatter as you keep storing fat but never using it.
I definitely agree that exercise is great though, if only just for the feeling healthier and more energetic in general. I just go for an hour's walk a few times a week, and do some pushups/crunches etc. every couple of days.
Lifestyle Change (Score:4, Informative)
Actually the only way to do this effectively is to approach it as a change in lifestyle, and accept that this is how you are going to be eating for the rest of your life (if you want to stay in good health that is). The next step is to find a diet that can match this requirement. diets like weight watchers do work, but the most effective diet that I have found is a Low Glycemic Load diet. Stabilizing ones blood sugar automatically creates an environment where the body begins to rid itself of excess weight. I use the word diet in the context of a way to eat, and not as a means to an end. The next step is to learn to eat correctly and stick to
It. It takes about 3 months to learn to eat correctly, and can take about 6 months to become acclimatised to the new lifestyle. On a low GL diet one can lose 1 to 2 pounds a week. This continues until you are within your normal body weight range, and then it stabilizes.
I would really recommend a low GL diet to anyone who is serious about wanting to switch to a healthy and vibrant lifestyle.
Re:How can that be? (Score:3, Informative)
I was grossly overweight to the point that the doctor was worried so I said to myself that this cannot go on. I changed the amount of food I ate from large dishes to normal dishes and skipped any evening meals except vegetables. I also picked up daily one hour walks or swimming. During 4 months I lost somewhere close to 100 pounds and felt great.
Re:Hackers Diet FTW. (Score:5, Informative)
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. (Score:3, Informative)
You get ripped off very badly in health food shops. If you're in the UK, you can get some really good quality stuff here [myprotein.co.uk]. Alternately, just eat a proper meal after your workout which is best anyway. Work out before breakfast, before lunch or before your evening meal. Carbs after workout helps stimulate muscle growth and it also means that you'll be more likely to exercising on an empty stomach which helps stimulate fat burning (especially before breakfast).
12 weeks? (Score:5, Informative)
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".
Re:Conservation of Energy (Score:2, Informative)
Unless you mean caloric intake in the sense of long-chain starches, etc. that are undigestible by the human body. I'm guessing these don't figure in to the daily calorie allotment.
Yes that's part of what I mean. I'm not sure how the daily calorie allotment is arrived at. Ultimately, I don't think it really matters and I'd assert that, with modern diets and environments, psychological and physiological factors have a far greater influence on weight than mere thermodynamics.
Fiber intake (which ideally should be relatively high) prevents absorption of a percentage of fats and carbohydrates. It suppresses appetite and regulates insulin levels, thus reducing total caloric intake. In a high-fiber diet, up to a fifth of all fats are passed directly through in excrement. Fiber promotes regular bowel movement and thus decreases transit time. The fiber itself is undigestible. The website I was getting the "50%+" figure from was unsourced so it probably exaggerated, but add in fermentation of gases and urine losses, and it's possible for a large portion of caloric intake to pass out of the body undigested.
http://www.mc.vanderbilt.edu/documents/MPB/files/calorie.pdf [vanderbilt.edu]
http://en.wikipedia.org/wiki/Dietary_fiber#Fiber_and_calories [wikipedia.org]
http://www.springboard4health.com/notebook/nutrients_fiber.html [springboard4health.com]
Re:Unfortunately not (Score:5, Informative)
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:Hackers Diet FTW. (Score:2, Informative)
I understand your situation as a woman: I went through all this with my girfriend, and she's my workout partner. She did get down to flat abs and muscular legs, but she had to watch her carb a lot more than I did in order to get to that point. It was a lot harder for her, but we used essentially the same system.
As you said, women have a lot less testosterone: it's really difficult for most women to pack on muscle. From that standpoint, I don't think very many women have to worry about becoming muscle-bound, unless they're on hormone therapy or something.
There's also this whole genetics situation. I was 110kg and failing to drop weight virtually no matter what I did. I decided that if I was destined to be a big guy, I might as well make my chest an legs larger so that my waist looked smaller in comparison. My gal was the same way. She'd been big her whole life. Over the last three years, her legs went from big and flabby to big and strong. I don't think there was an option C (for small legs). She's a muscular 65kg and hhhhot. Who's going to bitch about that?
Re:Hackers Diet FTW. (Score:4, Informative)
Sociopath (Score:3, Informative)
This post is extremely misleading and dangerous. Why anyone would want to propagate this lie is beyond me.
Exercise does lead to weight loss. The article cited clearly says it does. It's just that a small amount of exercise -- aerobic exercise for short periods over a mere three months, without strength training or diet changes -- is less effective than you'd want it to be. Well duh. But even in those circumstances, with all those factors stacked against weight loss, the participants still lost some weight.
A counterexample: A mildly overweight or average person, who has no heart problems and is otherwise healthy, can engage in much more vigorous exercise. An hour on the elliptical can burn approximately 700 calories. An hour in an intense gym routine can burn more (ever see those ads for LA Boxing touting the one-hour 1000 calorie workout?). Lets say you do an hour of 700-calorie cardio every morning and dont change your diet. That's an additional 3500 calories you're burning per workweek. If you give yourself weekends off and don't change your diet and don't strength train, you're still losing a pound a week, mostly of fat. If you add in proper diet -- not calorie restriction per se but just switching from soda to water or cutting out one or two greasy meals a week -- you're doing better. Add in strength training and you're be doing amazingly.
But it's not enough to just diet. The health benefits of good cardiovascular health and muscle strength are important in their own right. Things like the Hacker's Diet work to lose weight, but they are very unhealthy, even possibly dangerous. It condones a quantitative instead qualitative approach; the Hacker's Diet seems to take the position that you can eat microwave pizzas for every meal as long as you keep it under about 2000 calories. What it doesn't tell you is that in the process you'll be failing to provide muscular support for an aging skeletal system, adding cholesterol to your body, hardening your arteries, and atrophying major muscles.
good calories, bad calories (Score:2, Informative)
the book by that title has pointed this out for years.
Re:What about the slowing metabolism? (Score:3, Informative)
You can't be "ripped and obese"--obese means very fat--but I know what you meant.
It's not true that the only way to lose fat is to combine weight lifting and exercise with a low calorie diet. Plenty of people lose fat without weight lifting. Although including strength training (it doesn't have to be with weights) is probably the best way. There are a variety of magic tricks in the creation of lean body mass. Here is what they are, and why they work:
1. Weight lifting, particularly big lifts like squats and deadlifts. Why it works: 1) because these lifts increase body hormones associated with muscle mass creation, and 2) it requires a great many calories to build and sustain muscle.
2. Cardiovascular training in the early morning, before eating. Why it works: because in the early AM your body is high in lipases, which promote the burning of fat.
3. Eating of low glycemic index foods, and/or the eating of frequent small meals (as opposed to less frequent large meals). Why it works: prolonged periods of the day with low blood sugar cause the release of neurotransmitters, hormones, and peptides associated with starvation, causing your metabolism to drop. Basic dietary changes can prevent.
4. Lower, but only slightly lower, calories consumed than expended. Why it works: same reason as above; prevents the starvation response described above.
5. Avoidance of compensation behaviors. After exercising intensely, the body has two natural inclinations: 1) eating of reward foods, and 2) a tendency towards compensating rest. Solution is to avoid the reward foods and make certain to stay active regularly. I.e., did you lift weights in the morning? Consider a walk before bed.
6. Are you crash dieting? If so, know that your body will compensate with a starvation hormone response, lowering your metabolism (and increasing your hunger!) in response. If your diet is very low in calories, you must exercise to keep your metabolism high. Stimulants work, too, but are only secondary.
7. On a diet, hunger tends to increase. If you exercise enough, you will need to eat more. It is better to acknowledge this and plan for the eating of healthy foods than attempt to fight it, fail, and eat crap. Plan ahead. Eat more lean protein sources when you can, and keep low glycemic foods around for snack attacks.
C//
Re:Telling that to someone starving to death (Score:4, Informative)
Re:Hackers Diet FTW. (Score:4, Informative)
"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."
I run marathons in the summer and do strength training in the winter. Without a doubt I can say marathon training burns far more calories than strength training ever will. I actually bulk up and put on fat when I do strength training. Marathon training on the other hand presents me with the challenge of trying to keep weight on, but that's to be expected when you burn through ~3,000 calories in an afternoon.
It's the hormones that control fattening, not fat. (Score:2, Informative)
His rather prolific research into the history of the science of obesity, diet, nutrition, and "diseases of civilization" are mind-blowing. (see link to video below)
Especially to geeks who know that sometimes EVERYONE gets it wrong.
In this case, the common (mis)understandings have tainted the understanding of an entire generation of scientists and thus the people they inform.
In a nutshell, it's all about the only hormone in the body that turns ON the fat storage system. All others, including dopamine, adrenaline, etc. tell the body, HEY WE NEED ENERGY NOW, and so energy flows OUT of the fat system. The one hormone that flips the switch to STORAGE is INSULIN.
So when the body has plenty of insulin, its IMPOSSIBLE for it to go back to RELEASE fat mode.
What causes insulin to be released? All carbohydrates do. The #1 of those is GLUCOSE. The others all do to a greater or lesser degree (read about GLYCEMIC LOAD/INDEX).
So without glucose (and the other oses) there is no insulin released. No insulin released means the body stays in the natural energy release when needed mode, not stuck in storage mode.
To add to the trouble, one effect of insulin release is actually HUNGER itself. Thus creating a feedback loop.
Bottom line is, and unbelievable as it sounds in the face of modern "nutrition science", humans don't need to worry about their blood sugar levels being too low. Too high, and chronically elevated, mean the body can't release the fat, no matter how much exercise is done.
Finally he shows how fat has been wrongfully vilified over the past 50 years, and so if you take fat (high-density energy storage) out of the diet, it is replaced with carbs, and that itself is what triggers the storage system.
Taubes has a great one hour video lecture that is very geek friendly.
http://dhslides.org/mgr/mgr060509f/f.htm [dhslides.org]
http://www.google.com/search?q=taubes+adiposity+101 [google.com]
Geeks, you're the only ones who can grok this easily as you RTFM -- well Taubes has wrote the book on it, and if you're curious about why science could be so wrong, start your search engines and know there's a huge revelation that you'll not only say WOW to, but you'll realize that you can help spread the word of how to stop the spread of obesity...
Good luck geeks!
p.s. the key to it all may be the GLYCEROL-3-PHOSPHATE (aka ALPHA GYLYCEROL PHOSPHATE) ... which is the backbone of the stored form of fat in the fat cell. The triple glyceride molecule is too big for the "loading dock" and so transportation in or out of storage necesitates the disassembly of free 3x glycerides down to 2x, and then reassembly inside the fat cell back to 3x. And the best ironic bit, the G3P/AGP is an EXHAUST PRODUCT of the "burning" of the sugars! So it's actually like some component of the car exhaust actually causing the "environmental change", so its not even the energy of the sugars (and starches; which are actually sugars our taste buds can get a 'grip' on to taste as sweet), but rather a by product of their use.
Without excerise I went from 300 lbs down to 165, so it must work... YMMV ;-)
Finally this comment is probably too late to get modded to visibility right now, but if you find this down the road and want to know more, don't hesitate to ask and send an email! The more geeks aware of this, the more ability we have to help others understand too.