It's not just how many calories, but what kind, study finds | Hacker News Reader

It's not just how many calories, but what kind, study finds

latimes.com

29 pointsrf4543 comments

Didn't this study have a terribly small sample size? 13 adults were divided into 3 groups. That is 4 people in each group. There must be major individual differences how their bodies react to different diets during a four week period. I don't see how this is statistically significant.

13 men and 8 women for 21 total people. The article also mentioned on multiple occasions the small sample size.

Is this news? I was under the impression that it was fairly common knowledge that all calories aren't created equally.

It is definitely not common knowledge amongst the general population.

I believe low-carb diets (low carb, slow carb, paleo, etc) are well understood and praised amongst people with interest in nutrition and fitness, but it's still slowly making it's way into the general population.

> It is definitely not common knowledge amongst the general population.

For a good reason. First and foremost, general population just needs to eat less, a lot less. Once we get past that point, macro-nutrient composition can be the next level of diet optimization.

I like meat and meat keeps me full for longer periods of time, while at the same time whenever I eat rice, or potatoes, or pasta (without any meat) I feel hunger in 2 hours tops.

I don't know if this is a property of high-fat versus high-carb diets, but either way it's a mistake to think in absolute terms.

I also disagree that we have a weight problem because "we eat too much". I lost more than 40 pounds by cutting all the sugars from my diet, while still eating plenty of food.

I meant eating less in terms of calories.

I know what you meant, but I don't think this strategy works, mostly because "eating less calories" has to be a side-effect of a healthy diet not the goal, otherwise it isn't sustainable.

I tried it myself and it didn't work. The mental pressure, the guilt when you go wrong, the bad moods you have when you can't satisfy some urge - all of these are culminating with depression, until finally you give up because being overweight suddenly doesn't seem so bad.

Besides I've seen some statistics with the growth of the average caloric intake in the past couple of decades, compared with the growth of sugar intake and the growth of sugar in our daily diet has a much, much better correlation with the rise of obesity and diabetes.

People should be encouraged to stop eating crap that they don't even like and start eating good and healthy food.

But why do they eat too much? Two things to consider: higher fat meals can make you feel sated sooner, so you eat fewer calories. Also, there is evidence that carbohydrates trigger an insulin release which activates a hunger response.

I never understood the satiety argument. Fat also packs more than twice the calories of carbs. It needs to fill you up twice as fast or keep you full twice as long for this argument to work.

Besides, the body takes about 20 minutes to send the first "I am full" signal anyway. I can go through the majority of a large pizza within that time with my "normal" eating pace.

There are a lot of people who insist that calories must be equal in terms of weight loss/gain, or else there would be violation of the laws of thermodynamics or something...

To quote Gary Taubes, who tries to puncture this myth:

The reason people believe we get fat because of overeating and sedentary behavior is because they believe the laws of thermodynamics somehow dictate this to be true. In particular the first law, which tells us that energy is conserved, so if a system takes in more energy than it expends, the energy contained in the system has to increase. If that system happens to be our fat tissue, than the fat tissue accumulates fat. That’s the logic. So if we eat more than we expend, we get fatter and the logic turns this around to say that we get fat because we eat more than we expend. And so, overeating and sedentary behavior are the causes. This is the logic that leads virtually every government health agency and independent health organization (the AHA, the AMA, you name it) to have some variation of this World Health Organization statement on its website or in its promotional material: “The fundamental cause of obesity and overweight is an energy imbalance between calories consumed on one hand, and calories expended on the other hand.”

I don't understand how this quote from Taubes proves anything. If I stop eating, I will lose weight and eventually die. Also, if I eat more, I will gain weight. Thus calories must have SOMETHING to do with weight, right? I think Taubes is fighting a straw man here: I haven't heard anyone argue that eaten calories are stored in 1:1 ratio. But they have some causal relationship.

If you read the whole article, Taubes isn't saying that there is not a link between calorie intake and weight-gain - what he is saying is that it's not "causal" in any useful sense. Why exactly overweight people consume more calories is still a mystery and it's a gross oversimplification to discuss the law of thermodynamics when considering "why someone is overweight".

I haven't heard anyone but Mr. Taubes "discussing the law of thermodynamics". For me, there is zero mystery why obese people are fat. They have eaten and continue eating more (calories) than other people. And they will get less obese if they eat less. What exactly is the mystery here?

Sure, if you stop eating you will lose some weight and die. But, you can die of starvation while obese. In animal studies, it is possible to reduce calories and the animals won't lose weight or to add a lot of extra calories and not become obese.

Calories have something to do with it because they are one part of the equation. Calories in does equal calories out. Calories In = Calories Stored + Calories Expended. But, the mistake is in thinking that the law of thermodynamics means that the type of calories in doesn't impact the ratio of calories stored/expended -- the variables are not independent. The content of the food you eat impacts: your hunger, your energy level, fat storage rates, and your metabolic rate, all of which mean that attempting to cut or add calories may not have the expected impact depending on what the food is.

Got it. I've heard that theory before but never have I seen any substantial evidence. I accept that the food I eat might have some effect on my "hunger" and "energy level". Which in turn could make me eat more or exercise less. That doesn't really have anything to do with calories per se. Many other causes have the same effect, e.g. psychological or hormonal situations. However, the real argument seems to be that what one eats impacts one's "fat storage or metabolic rates". That's hard to believe. It would be interesting to see some hard evidence to support that claim. The present study tries to give some results, but I think the sample rate is insufficient. I've seen much evidence to the contrary.

The idea that carbohydrates impact fat storage through insulin is one of the main arguments put forward by Taubes in his book, and he provides a lot of evidence and studies to back up his assertion. He may be wrong (and he somewhat acknowledges this and calls for proper studies to be done), but it's worth reading if you want to understand what the argument is.

BTW, could you refer to some of these animal studies that show that reducing calories does not impact the weight? I hope the animals in question are not for example ants but more like primates or something resembling humans.

People talking like you can perform a thermodynamic analysis of nutrition is definitely a pet peeve as a physicist.

+1 it drives me crazy too. Calories are a unit of stored energy. Wood has plenty of calories (great for fires) but if you eat a bunch of bark you're not going to store that weight, you're just going to make yourself sick.

Yes as and no. Fundamentally weight gain/loss really is a matter of calories in vs calories out; if you're burning more calories than you're consuming then you're gonna be losing weight. It's akin to saying that all you need to do to win at golf is to hit the ball really hard towards the hole -- true, but not necessarily good advice.

The reason sometimes we put too much emphasis on the basic-thermodynamics side of things is that we're busy fighting a war against dumb fad diets.

But once you acknowledge the basic calories in vs calories out principle, you can start thinking about what foods make it easiest to maintain a caloric deficit. Even the most 'traditional' of health authorities acknowledge that this is a factor, which is why they won't say "Hey, whatever, eat three slices of chocolate cake a day and nothing else". The first factor is making sure you get sufficient nutrition along with your calories, the second is making sure you feel full while maintaining a caloric deficit. There's a growing acknowledgement that low-carb diets can help with both of these.

This study suggests a third factor: that eating a low-carb diet can actually boost your base metabolic rate. How? Not sure. It would be interesting to see whether it gets replicated in a larger scale study.

Other studies have explained/tried to explain how the low-carb diet (i.e., Atkins) work. The basis gist of those studies is that the body burns fat reserves instead of carbs. Burning fat requires more energy than burning carbs, which increases the body's BMR.

Except that many have been trying to prove they are created equal. http://www.slashfood.com/2010/11/09/eat-twinkies-lose-weight...

Argh! The caption in this article makes a grammatical mistake that is a pet peeve of mine. I cringe every time I read or hear it!

An example: "Not all the donuts are eaten." "All the donuts are not eaten."

Assume some donuts have been eaten. Which is correct?

As I understand English, the first is logically correct, but the second is typically used.

I apologize now to all of you who have never noticed this before, as it may haunt you now for the rest of your lives.

The assumption that "natural language grammars" and "logic" are even on speaking terms will only bring you frustration, as you rail against perfectly correct constructions while the world rightly ignores you.

When someone wants to negate the idea of a sentence, the negation is often placed in a spot that makes it unclear as to whether the sentence is being negated, or merely a smaller part of the sentence is being negated. This is a common occurrence in many languages and dialects.

Of course it can be confusing, and sometimes even downright contradictory if you think too hard about it. But language is flexible, and most people just don't write with such rigorous logic. So, just mentally realize that, given the context, the most likely interpretation is:

"all calories are not alike" = NOT("all calories are alike")

If this is still haunting you, just do what Allie does:

http://hyperboleandahalf.blogspot.com/2010/04/alot-is-better...

I think what he's saying is that the noun is poorlly chosen. The proper, unambiguous sentence should have been: "some of the donuts were eaten" or "some of the donuts were not eaten."

The "not" is correctly used in either case, except in the edge case of "all" or "none".

This is very much...not new news whatsoever. I thought it was pretty common knowledge you need different types of calories.

This piece also seems to be pretty marketing/weight loss heavy, as opposed to proper nutrition. (I think for an active person, a proper diet is around 40% calories from protein, 30% from both fat and carbs?) or do I have protein and carbs swapped...?

The point was more than the caloric intake should be balanced across carbs, fats, and proteins (the exact ratios would vary depending on need). In other words, low-carb or low-fat were worse overall than a diet which did not artificially deflate consumption of fat or carbs.

Summary:

"Subjects burned more than 300 additional calories on average when on the very low-carbohydrate dietcompared with the low-fat diet."

"Subjects burned 200 additional calories on the low glycemic index diet than on the low-fat diet."

"Ludwig also didn't recommend a very low-carb diet even though it offered the best metabolic edge. Some measurements suggested it could be risky for the heart, he said."

"The low-glycemic diet — which he has recommended for a long time — did not seem to have these problems, he said, making it the best bet."

"A low glycemic index diet is rich in whole grains, fruits and vegetables and is designed to prevent sharp spikes in blood sugar"

Insulin not only causes your body to store more energy as fat, but also interferes with memory formation.

*edited, more to the point.

It should be noted that a kcal /is/ still a kcal; The adaption your body takes after being given different levels of macronutrients doesn't change that if you eat more than you expend, you will put on weight.

Also, I'm surprised that they didn't trial a 60% protein, 20% fat and 20% carb diet!

Actually, no. Here's an article that explains why this is not the case:

http://garytaubes.com/2010/12/inanity-of-overeating/

While an interesting read, it feels like I just read some long winded analogy describing metabolism?

In the parent comment, I'm including bodily factors like metabolic reactions within "expend". The degree to which this makes a difference in overall expenditure is the un-quantifiable part; but adjusting your diet further to counter this lack of expenditure will still have the same effect. It still is a numbers game in my mind.

I see this reaction all the time:

"A calorie is a calorie is a calorie. If you want to lose weight, you just need to eat less."

"Well, no, your body can react differently to different types of calories. If some calories tend to induce hunger and others don't, then it matters quite a lot which calories you consume."

"Well, yeah, sure, everybody knows that."

Well, no, everybody may "know" it, but when you're not looking, they'll slip "a calorie is a calorie" right back in.

This matters. Either eating certain foods induces more calories to be consumed, in which case the key to dieting is to eat certain foods and not eat others and decades of consensus and advice are irredeemably, irretrievably wrong, or a calorie is a calorie and these sorts of studies are irredeemably, irretrievably wrong (as this is hardly the first one to suggest lower carb or lower GI diets are superior). Some people seem very comfortable just sort of sliding into the "sure, calorie type matters" whenever it is argued, but somehow not being willing to follow the logic that if calorie type matters, then certain further research and conclusions are called for that are sharply at odds with conventional wisdom, which has been very, very much that a calorie is a calorie is a calorie when it comes to weight gain.

Conventional wisdom and decades of dieting advice have been deeply, profoundly, foundationally based on a calorie being a calorie being a calorie, and if that is not true, the conventional wisdom is deeply, profoundly, foundationally if you like, flawed. There's no two ways around this.

(Though I absolutely, positively guarantee that if it does turn out that calorie type matters that this move will be used to slowly but surely rewrite the last 50 years of dietary history such that the conventional wisdom was always right and never said anything about calorie types not mattering. But it won't be true.)

kcal may still be a kcal when verified in a bomb calorimeter - I believe for food they do it the same way everyone else does it: Put it in pure oxygen atmosphere, and light that baby on fire, measure the increase in temperature in a controlled environment, and the 'heat' produced is expressed in kcal.

now, my body does not have an active flame, and I don't have a combustion engine in my stomach. I use a (mysterious to me) metabolic process to convert what I eat into energy that my body can use.

For me, an individuals metabolic rate may be roughly proportional to kcal intake, but it is not the same thing, and it is different for different food types, combinations, and for different people.

I liked the article - even though I am not a dietician, I do think there is something wrong about the Adkins diet.. not healthy.

You are right that you have to adjust for metabolic rate; and while the content of your diet will have an effect on that rate (meaning getting an entirely accurate assessment of your expenditure is near impossible) the kcal value maintains;

I suppose it's my mentality that you adjust your eating habits based on your diet contents and its effect on metabolism, to match the kcal values, rather than viewing the kcal as an inconstant value.

Thank you, by the way. I enjoyed the opportunity to think though this

This dialog reminded me of a rumor I heard awhile ago about trying to measuring efficiency of Lance Armstrong (competitive cyclist). A brief search gave me [1], but I'm sure there are better articles out there. My big take away is that even with modern technology and understanding there is just so much we still don't fully understand - especially about the human body and processes.

[1] http://www.sportsscientists.com/2008/09/coyle-and-armstrong-...

The trouble is that your digestive process isn't necessarily time-independent, so the same piece of food could represent different energy fluxes into your body if eaten at different times, and the calorie expenditure of your body isn't necessarily time-independent, so the same exercise (including just sitting around) could represent different energy fluxes out of your body if performed at different times.

Without actually measuring energy fluxes, "a kcal is a kcal" is meaningless.

The point of the original study was: 1) For weight loss, how many calories you eat (or don't eat) matters more than any other factor. 2) Once the weight loss period has ended, the type of diet (i.e., the balance of calorie types consumed) matters more for maintaining the new weight and overall health.

Really? I thought this was known already...you needed to do research to discover this? Now I didn't read the article, but if they did research to discover to what extent the exact differences result in, then that's fine I guess...but judging from the title that's not the case.

Marion Nestle of the Politics of Food, wrote about this study early this week (http://www.foodpolitics.com/2012/06/does-where-calories-come...)

She's skeptical. Basically, she says you cannot really draw any reliable conclusions becuase of the short, highly controlled conditions of the study.

See: this is such a hot topic that Taubes-fans actually down-vote you without bothering to discuss or present some arguments. You brought some valuable information to the discussion and you got downvoted for that. Hurray, HN!

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