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.

[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.

[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.

[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: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?

[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: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.

Density

[Mathinker]

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

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

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.

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.