by okayfruit » Fri Aug 01, 2014 9:55 pm
In the Ridaura article it mentions how both obese and lean mice were fed the exact same diet that was low in fat and high in plant polysaccharides, indicating that the difference in weight between the mice is not due to a significant difference in diet. People who are predisposed for this can have very healthy diets and still be overweight, and with only very drastic changes in their diet (such as strictly controlling what they consume) can they lose weight. People who are genetically predisposed towards gaining weight w/o the difference in gut microbiota generally have a really fucking low BMR and are more efficient at absorbing nutrients (their small intestinal lining might have significantly more folds than your average person).
To be honest I think simply calorie counting is kind of a dumb way of losing weight. Consuming less calories required for your BMR+calories expended will *always* lead to weight loss, but your average person's going to have a super difficult time figuring out their BMR and how efficient their body is at absorbing calories. I'll emphasize yet again that this by no means goes against the laws of thermodynamics. Everybody's body requires different amounts of energy to keep shit going, like your organs and stuff. This varies from person to person. Additionally, you can eat 2000 calories but only absorb 1500 (this is kind of an exaggeration though), and the other 500 calories you will poop out.
What if you ate 2000 calories (determined by ones measured by a calorimeter) but only expended 1800 calories a day? First, let's just forget about "oh fiber's more filling" by pretending that by some magic we've managed to make the two into equal volumes. You're less likely to gain weight with 2000 calories of pure fiber because it takes a ton of work just to break down soluble fiber, and you'll end up pooping out a good portion of it because that shit passed through your GI tract before you got the chance to break it all down, making the net # of calories gained by your body less than if it just at 2000 calories of sugar, because it's super fucking easy to just absorb all of the sugar at once with minimal effort expended by your system, and you'll only poop out a very very small amount of it.
I think point you missed in my last post is that not all calories in a single item of food are available for you to use or absorb, so I'll do my best to illustrate it. Let's take a potato, for example. It's got the same # of calories when it's either raw or boiled have the same # of calories, which is about 280. Let's just pretend for the sake of making my life easier that this potato we're talking about is purely made of carbohydrates, and consists of 0 bean energy and 0 lipids. So you have 280 calories worth of starch that gets broken down into glucose and then blah blah blah. So Jim eats 10 raw potatoes and Manfred eats 10 boiled potatoes, 2800 calories each, and these two dudes are physiologically identical. Despite this, Manfred's gonna get more glucose in his bloodstream and his body's going to tuck away more glucose in his fat deposits. Jim is going to poop out most of those potatoes. It's because the glucose is less accessible in the raw potato due to it being compacted into starch granules, which loosen up in the process of cooking. These two dudes can continue their diet of potatoes and Manfred, after a certain period of time, is going to be way bigger than Jim. Even if Manfred starts to eat 8 potatoes, he's still going to be fatter than Jim if Jim's gut can only get 7 potatoes worth of glucose. This, I will repeat yet again, does not go against the laws of thermodynamics because Jim's still pooping out those 3 extra potatoes. A bomb calorimeter gives the same # of calories for both potatoes because it incinerates those potatoes and doesn't give a fuck about chemical bonds, but your body only has so many enzymes and a certain amount of time to break stuff down.
I'm not going to go into depth about the different pathways that stuff is stored because I'm pretty sure no one wants to hear me drone on and on about biochem and count ATP/NADPH used at each single step, but please at least just take my word when I say certain macronutrients (I've listed the 3 above) makes your body spend way more energy to convert them into usable or storable energy, and the amount of energy expended still varies with the same macronutrient.
Anyways, apologies to everybody else for clogging this thread up with boring science talk. I really do think obesity is a serious health issue, but weight management would be a little bit easier for everybody if we focused on eating better, not eating less.
TL;DR: Calorie counting isn't great because net calories gained = calories listed + calories pooped out + calories expended for digestion. Last two variables differ greatly based on the type of food you eat. Take 2 foods (x1, x2). For calories listed, x1 = 100, x2 = 90. Calories pooped out & expended (x1) = 30, and for (x2) = 10. Net calories (x1) = 70, (x2) = 80. Laws of thermodynamics still apply.