Every single hospital-ward double blind clinical trial over the last 100 years says exactly the same thing: net energy balance is what determines how fat you are, no matter the macronutrient content of the diet.
Nutrition's role in lifelong health is a LOT more complicated. What your lifetime Vitamin D levels probably matters a lot. But over a lifetime, eating a diet of mostly whole foods, and in amounts scaled to activity is going to give you benefits that will completely drown out what kind of fat you ate over the last 30 years or if you ate pop tarts for breakfast.
My point is, if you're fat and unfit, it's not any particular macronutrient's fault.
Here's my problem with this: the energy balance theory is the status quo, yet for as many studies as you can dig up to support it, you'll also find conflicting observations (some of which also go back over 100 years). I'm not saying it's wrong, I'm simply saying that the hormone theory of obesity shouldn't be disregarded solely because it doesn't fit the status quo. It needs to be tested.
Another problem I have is that the energy balance theory is just too convenient. It's a greay way to dismiss obesity as a simple failure of willpower, and to dismiss the obese as being morally inferior to the rest of us. In other words, our judgmental attitude toward obesity could be blinding us to its real cause. Let's test the hormone theory, and if it turns out wrong, we've only learned more about obesity. If it turns out correct, we could possibly save many lives and prevent a lot of suffering.
That said, I find it absurd to believe that only energy balance matters. In effect, this predicts that despite the dozens of hormones involved in human metabolism, it all boils down to caloric content. That doesn't make any sense to me. Taubes actually wrote an interesting thought experiment on this: http://garytaubes.com/2012/11/what-would-happen-if-thoughts-...
I think you are confusing weight & body composition with "health". They are interconnected but not the same thing. I believe (and it is just a belief) that a lifetime of staying lean (& strong) is the single best way to maximizes the health benefits of a diet, whatever that diet may be. You can't eat "unhealthy" amounts of any macronutrient if you're eating to stay lean (<15% body fat for men).
Don't pull out the "a simple failure of willpower" straw man; I never claimed that.
Hormones play a HUGE role in metabolism. My bedtime reading is how the chemical reactions they drive fit into human metabolism. you're comment seems to make them out to be "magical", which I suspect is due to your ignorance of them. I highly recommend reading up on them, just not via the media (Taubes only gives you his choice of the science), but via biochemistry text books like "Advanced Nutrition and Human Metabolism" http://www.amazon.com/Advanced-Nutrition-Metabolism-Sareen-G...
* there are extreme exceptions; liposuction is one way. :P
I'm not claiming that the body can somehow defy the laws of thermodynamics. Obviously to become "heavier" one must consume more energy than one expends, but to lose fat -- specifically fat, not muscle tissue or bone or water -- the question is this: how important is the role of hormones in fat regulation? Does an increased insulin load, coupled with insulin resistance caused by long-term exposure to chronically high insulin levels, promote greater fat storage? And does this greater mass of fat, which itself is a hormonally active organ, affect the body in a way that results in illness and further weight gain?
Would an endocrinologist tell a diabetic that macronutrient content doesn't matter? Should we give that same advice to people with metabolic syndrome or those who are at risk of developing it? If insulin resistance is the primary cause of Type 2 Diabetes, and insulin is the primary hormone involved in fat storage -- both non-controversial statements -- then wouldn't it make sense for those at risk of developing T2DM to eat foods that produced a minimal insulin response?
Read Taubes's thought experiment I linked above. If you're willing to make nutrition texts bedtime reading, then you will at least find it interesting, even if you disagree with it. Though Taubes is not a scientist and he doesn't claim to be, he does make a compelling argument.
> Don't pull out the "a simple failure of willpower" straw man; I never claimed that.
It wasn't intended to target you specifically, but this attitude is pervasive, even among medical professionals. There are people out there who would much rather believe that every obese patient is just a lazy glutton who can't control himself. I know a few of these people myself, one of whom is a prominent oncologist. Science requires that we put aside our biases and assumptions.
> Hormones play a HUGE role in metabolism. My bedtime reading is how the chemical reactions they drive fit into human metabolism. you're comment seems to make them out to be "magical", which I suspect is due to your ignorance of them.
I'm not claiming hormones are magical. I am merely suggesting that their known role in fat regulation might also play a critical role in obesity. It's been a while since I studied the topic in any great depth, so I can't compete with your bedtime reading, and I don't want to link spam, so I'm keeping it simple.
Anyway, I believe the science will eventually shed some light on this issue. There are clinical trials in the planning stages right now, so hopefully we won't have long to wait.
> And does this greater mass of fat, which itself is a hormonally active organ, affect the body in a way that results in illness and further weight gain?
These are very good questions. Here's what I know (caveat it may not be complete, but I am confident it is accurate):
1: Hmm, chronically high insulin levels is caused by chronically eating too much. Beef spikes insulin just as much as table sugar (http://ajcn.nutrition.org/content/66/5/1264.full.pdf#page=1&...). So I would say the problem of "chronically high insulin levels" is a problem of eating too much food, not too much sugar.
2: This is a hugely interesting area of thinking for me. Which fat though? White or brown adipose tissue? Brown fat is darker in colour due to it's huge cellular density of mitochondria when compared to white adipose tissue. It's essential fat-buringing fat, and plays a role in regulating temperature. It basically burns fat to warm us up when we're cold. This is why Michael Phelps can eat 10 million calories a day. 6 hours a day in water requires allocating a LOT of calories to maintain core body temp. We have learned SO much about fat tissue recently, but I don't think we have all the answers yet.
I noticed this red-flag from the thought-experiment:
> We know the liver will turn some of this fructose into fat and if the fructose is delivered quickly
Yep, but less than 1% is converted into fat (http://www.nutritionandmetabolism.com/content/9/1/89), and this is in a state of caloric surplus. The thought-experiment method is for the subjects to eat calories to match their TDEE (Total Daily Energy Expenditure), so it's much more likely that none of this fructose will be converted into fat, it's more likely to completely converted into glucose by the liver.
> Let’s assume two things for the sake of argument. the sugar in A’s diet causes A to become insulin resistant. And second, insulin works to put fat in fat tissue.
I would say both assumptions are fallacious. Eating @ TDEE means 100% of the food energy is used up, and fat cannot be made from nothing. More sugar in this case does not cause insulin resistance, beef stimulates insulin release into the blood just as much as sugar does, so one can't isolate a single macronutrient like that. Also, the "insulin works to put fat in fat tissue" is misleading at best and completely wrong at worst, depending on how you interpret it. Insulin works to move nutrients into cells. More insulin in the blood is a signal there is food calories available, so insulin also stops fat cells from releasing their fat. This makes total sense; why dip into your savings when you just got a fist full of cash? The point where your body transitions towards fat storage is the point where your energy intake exceed energy expenditure; again just simply eating less solves this.
My statements are all for average healthy people. I totally agree metabolic-syndromes like diabetes should be treated differently. But the VAST majority of people are fat because they sustain consuming more energy than they use. The micro-variables like how stressed you are (and therefor how much cortisol hormone is present) matter, but nothing gets diet-induced hormones working as they should better (in healthy people) by just eating food-energy (whatever the macros) to match your activity over the long run.
Yes, beef does have a high insulin response, but when total consumption is taken into account, and satiety, eating beef will have a lesser effect than eating jellybeans. Look at the insulin scores in the publication you cited. Those with the highest scores, as a group, are snacks and confectionaries, foods that are commonly eaten in Western countries. Some of the worst offenders in the groups tested are: beans, potatoes, white bread, jellybeans, etc. -- carbohydrates.
> 2: This is a hugely interesting area of thinking for me. Which fat though? White or brown adipose tissue? Brown fat is darker in colour due to it's huge cellular density of mitochondria when compared to white adipose tissue. It's essential fat-buringing fat, and plays a role in regulating temperature. It basically burns fat to warm us up when we're cold. This is why Michael Phelps can eat 10 million calories a day. 6 hours a day in water requires allocating a LOT of calories to maintain core body temp. We have learned SO much about fat tissue recently, but I don't think we have all the answers yet.
In this case we're talking almost exclusively about excess visceral fat, though the role of other fats in obesity and disease is, as you said, not fully known.
>> Let’s assume two things for the sake of argument. the sugar in A’s diet causes A to become insulin resistant. And second, insulin works to put fat in fat tissue. > I would say both assumptions are fallacious. Eating @ TDEE means 100% of the food energy is used up, and fat cannot be made from nothing.
True, but activity level must be taken into account. Fat can't be made from nothing, but the patient could reduce his overall activity level as he becomes fatter, which would make excess calories available for storage as fat. In other words, we could have causality backwards: being lazy doesn't necessarily make you fat, but becoming fat could certainly make you lazy.
> Also, the "insulin works to put fat in fat tissue" is misleading at best and completely wrong at worst, depending on how you interpret it. Insulin works to move nutrients into cells. More insulin in the blood is a signal there is food calories available, so insulin also stops fat cells from releasing their fat. This makes total sense; why dip into your savings when you just got a fist full of cash?
If insulin stops fat cells from releasing fat, then wouldn't it make sense to keep insulin levels as low possible? That means reducing carbohydrate and protein intake, and increasing dietary fat consumption to compensate: in short, a low-carb, high-fat diet.
> The point where your body transitions towards fat storage is the point where your energy intake exceed energy expenditure; again just simply eating less solves this.
Does it though? Obese people have much higher concentrations of circulating leptin than the general population, and they can become leptin resistant. What happens if we tell these people to eat less, and move more? Chances are, they're going to become very hungry. I would argue that eating less isn't enough. They need to eat less insulinogenic foods, and compensate by increasing dietary fat to satiety.
> My statements are all for average healthy people. I totally agree metabolic-syndromes like diabetes should be treated differently. But the VAST majority of people are fat because they sustain consuming more energy than they use. The micro-variables like how stressed you are (and therefor how much cortisol hormone is present) matter, but nothing gets diet-induced hormones working as they should better (in healthy people) by just eating food-energy (whatever the macros) to match your activity over the long run.
Fair enough. That's the commonly held belief at least, but I disagree. I think we have an incomplete picture. However, I believe in the scientific method, so I'd really like to see clinical trials (not epidemiological studies) to fully test the hormone theory. As I said earlier, if it's wrong, then we haven't lost anything, and we've learned more about the role hormones play in obesity. If it's correct, then the impact on nutrition and obesity will be enormous. It's worth looking into.
That's a convenient fallacy which is so often repeated that it is simply assumed to be true, but some -- such as Gary Taubes, Dr. Lustig (the author of this article), Dr. Eric Westman, and others -- argue the exact opposite: the macronutrient content of one's diet matters very much. Different macronutrients provoke differing endocrinological responses. Our bodies are biological, not mechanical machines, and we process carbohydrates differently than fats or protein. It isn't controversial and it shouldn't come as a shock. New research is showing that the hormone cascade brought about by certain foods -- and by adipose tissue itself -- has an enormous impact on our health.
The problem is that people want to oversimplify nutrition into universal equation which assumes that everyone is the same, and they often cite epidemiological nutritional studies -- notorious for being inaccurate and unreliable -- to do so. The truth is probably more complicated: the diet that keeps one person healthy might make another fat and sick, and it's primarily dependent upon genetics, not physics.
For more on this, read any of Taubes's books. They are quite compelling. Dr. Lustig has written a few himself.