February 22, 2010
(Part V of a series. Go back to , , , or —or skip to .)
In previous installments, we've established the following:
- Hunger is not a singular motivation: it is the interaction of several different clinically measurable, provably distinct mental and physical processes.
- In a properly functioning human animal, likes and wants coincide; satiation is an accurate predictor of satiety; and the combination of hunger signals (likes and wants) and satisfaction signals (satiation and satiety) results in energy and nutrient balance at a healthy weight and…
Awesome article in a very cool series. Loved the energy density part. It's funny that Calories In/Calories Out always seems to be quoted by those advocating a low fat diet, but even that flawed theory supports eating a paleo diet over a low fat one.
That nutrition website is also pretty cool. For example, I found out that Skittles (you know, the food that has a lower GI than whole grain bagels) are more calorically dense than butter (830 vs. 717 per 100grams). Seeing as butter is basically pure fat, I was shocked. Looks like Skittles wins again!
You are right, I "didn’t know that prime rib is less calorically dense than rice cakes." Very interesting- thanks!
Holy, er, cow. I've more than half a mind to send this article to the folks at Weight Watchers. As a life-long dieter, I've always known their claim that drinking water and eating lots of high-fiber grains and vegetables to keep you "full longer" is a load of hogwash; it's nice to see that knowledge backed up.
The caloric density of processed foods was a bit of a surprise, even after eating paleo for more than a year. I occurred to me while reading the both lists that it's really hard to overeat the "rich" but less calorically-dense foods, and quite easy to overeat the processed crap.
Awesome. Thanks for giving some very clear ideas about what to do to help reduce hunger. I agree it is far more than stomach fullness. I drink tea with cream most days until noon or 2pm and break my fast then. I have a fairly empty stomach, and I feel it, but I am not hungry til early afternoon. Paleo wins on the satiety front. I totally agree on eating when you are rushed or in the middle of something else leading to overeating. If I eat while doing other things the food is gone before I realize it, and I am sure I am shoveling it in. That must definitely be part of the French paradox.
I had a friend selling a diet drink recently that was basically flavored metamucil. I have had far more success with dropping and maintaining weight than them - fiber is definitely not the cure-all it is marketed as!
Thanks for the article - it was very informative and will help remind me to eat slowly and reflectively.
Great article and thanks for taking the time to pull all this information together. The distinction between satiety and satiation and how they are initiated and satisfied (or not) is very interesting. This helps explain my experience on my previous "healthy" semi-vegetarian diet. I attempted to eat only until I was full or stop eating before I was full, all the while trying to discern clues from my stomach or brain. It always eluded me and I often wondered if there was something wrong with my sensor ability. For the last 5 weeks I've been following a primal diet and for the first time in my life I've felt what it feels like to be truly satisfied from a meal and I also find that portion control comes natural. I now eat until I am satisfied (or don't eat until I'm hungry) and it's not a mystery when that point is reached. What a concept!
Brilliant article as always, and one to be savored slowly for its many implications.
I've noticed whey protein often fails to satiate, supporting the common advice to "chew your calories". But now I wonder if sipping whey protein over, say, 15 minutes, might not be just as effective as masticating beef. Time for a self-experiment -- if I can stand it.
Another thought is that wolfing down one's food on the hoof or within time constraints promotes elevated cortisol, and we all know how that catalyzes fat storage. Extended, relaxed dining could be expected to minimize cortisol as well as allowing satiety to kick in.
Finally, I wonder if there is an enzymatic angle to all of this. Ingestion is not absorption; the latter requires amylase, protease, lipase, and all that good stuff, which the body can only secrete at a certain rate. Stuff yourself faster than your enzyme release rate and you can be sure of indigestion and all that entails. I know because I've done it way too many times.
Thanks again, JS, for distilling the research into a unified theory.
Maybe one of the problems with modern dehydrated foods is that people will drink modern, calorie-laden beverages to accompy them instead of water.
February 22, 2010
The energy density figures surprised me too: they were a late addition to the article.
Once I realized that just about every prepared food was more energy-dense than extra-fatty USDA Prime-grade prime rib (let alone the less-expensive, leaner meats we eat every day), I understood a lot about why it's difficult to feel "full" by eating snack foods...even if they're "low-fat" and made of "heart-healthy whole grains".
Again, energy density and "fullness" isn't the entire story, as stomach surgery results show...but it's one part of the puzzle. By eschewing meat, dogma like the Volumetrics Diet doesn't even play by its own rules.
Nutritiondata is great if you can ignore all the silly editorial comments, misleading banners, and derived statistics like "The Bad: This food is high in saturated fat" and "What's a heart-healthy diet?" The USDA database, from which all that data is scraped, is publicly available...but its interface is so poor and clunky that I refer to nutritiondata instead despite the baloney.
Most importantly, almost all shelf-stable foods are more nutritionally dense than prime rib, due to the dehydration.
I was surprised too! Thanks for spreading the article: I love debunking myths. It's nice to know that all those "rich", "decadent" foods we love are less calorically dense than puffed Kashi. Friggin' puffed Kashi! I ate boxes and boxes of that birdseed!
Remember that stomach fullness only affects satiation, not satiety. In other words, it is a factor in making you stop eating, but it's not a factor in whether you're hungry later...as you've noticed.
It's interesting that the old-school advice to "eat mindfully" actually has some basis in fact...and I strongly prefer the European technique of savoring a delicious meal with friends, as opposed to the Asian mysticism technique of "letting one grain of rice become your world" (a technique born, I suspect, of abject poverty). Remember that satiation can't make you undereat, because satiety is still the endgame...but it can help you stop overeating.
Absolutely! It's easy to get confused when we're trying to understand something that is actually two separate issues (satiation and satiety) in terms of a single concept. "But I just ate until I was full, and it's only an hour later, why am I hungry?"
Recall that even lean beef has substantial fat content, so you'll have to add some coconut oil or something to get a more fair comparison. You'll be testing satiation vs. satiety to some degree: whey protein shakes and coconut oil are unlikely to produce satiation, but they'll probably produce some degree of satiety afterward. (The literature is full of this sort of experiment, called "preloading": they feed people before a meal and then see how much they eat.)
I think the issue with enzyme release rate is mostly solved by the stomach. If we wolf our food down without chewing, it'll usually just sit in our stomach longer. The pyloric valve doesn't like to let solids through: it prefers
everything to have been reduced to chyme before releasing it to the
Recently, I read a long article about a guy in the 1800s who got shot in the stomach and recovered...but his stomach had a permanent hole to the outside. The doctor who treated him used him as an experimental subject, placing many different types and kinds of food directly into his stomach and seeing how long it took to digest them.
I'm not sure the two habits are causally related: people who eat Cheetos are probably more likely to drink soda than water, but I doubt that eating Cheetos causes you to choose soda over water.
Thanks, everyone, for your comments and suggestions. Keep spreading this article and series around, especially outside the paleosphere!
Awesome, thanks - there's heaps more than the caloric density of prime rib that I didn't know before I read your post. Looking forward to the next one - not satiated yet!
Great article and much more convincing then SG's musings about reward/palatability/bland vs. none bland etc.
But one thing: There are some traditional foods from fat and carbs which are indeed satiating, like ukranian Salo (salted fatback). If you have salo, rye bread and - vodka ;) you don't need anything else that night. http://en.wikipedia.org/wiki/Salo_(food)
And I remember my home made potatoe chips, sauted in a mix of coconut and butter oil were filling and satiating as well.
I think what I want to say is that SAFA is much more satiating (even without protein) then PUFA.
And we all know which one is in those snacks and packed french fries...
Interesting info - hadn't really thought about the energy density too much but it is something to consider. For a comprehensive list you can download the USDA's database if you are handy in MS Access. Website is: http://www.ars.usda.gov/Services/docs.htm?docid=20959
Quite, quite superb.
Your research has been so extensive.
I was not aware of studies regarding an involuntary homeostasis - the existence of a negative feedback - on intraday ingestion of the the major macronutrients. Thank you for the information.
In Winter-time I adore stews, thick soups and so on, and find both satisfying and satiating. There is an abundance of added water in these meals. I have never found much explanatory power in the notion of "calorie density".
February 22, 2010
We've got several installments to go yet.
Protein targeting isn't the only factor in satiety. I suspect salo (lardo, fatback), being a whole food, contains the fat-soluble vitamins and other nutrients -- so it's not nutritionally empty like a hexane-extracted, bleached, and deodorized seed oil.
Like you, I've also noticed that foods cooked with tallow or coconut oil (even refined coconut oil) are more satiating than the same foods cooked with seed oil. I have some ideas as to why that might be, but I need to do more research.
I appreciate the link, but I don't have the slightest idea how to use Access. I know someone who has made an app for her own use that allows easy searching and cross-referencing of the USDA database, but AFAIK it's not publicly available yet.
As far as Stephan's post, we're citing the same papers for the same reasons. Balsiger et.al., which I cite above, refers to the effects of surgeries that solely decrease stomach volume (stapling and lap-band) -- which are not nearly as effective as gastric bypass (roux-en-Y, or RNY), as Stephan correctly states.
However, I still can't make any sense of his characterization of the effects of gastric bypass. It is abundantly clear from the citations that "food reward" is being changed by the satiety response, which is what the RNY operation is modifying by dumping food directly into the lower part of the small intestine -- a fact he mentions explicitly.
It seems that he's so anxious to explain everything in terms of "food reward" that he's inverted the chain of causality...it's like watching a puppet show and concluding that the puppet is manipulating the puppeteer.
February 22, 2010
As far as calorie density, It's important to remember that calorie density affects satiation but not satiety. If you eat very bulky foods, you might be satiated more quickly...but as the stomach surgery and fiber intervention statistics show, this has a limited effect on food intake, because satiety remains unfooled by excess water or indigestible fiber.
It's also important to note that water in a soup substitutes partially or completely for water you'd have to drink anyway. Mainly I included the density statistics to show that the anti-fat, pro-volume diets lose at their own game, on their own terms.
Do dheagh shlàinte,
Great series, J.
Has anyone ever tried eating strained yogurt? I had some this morning after my eggs and bacon, and man, that's tough to eat quickly.
Parents might be able to chime in about the subsequent day eating (the 2-3 days routine). I've commented to my wife about how of kids seem to cycle two to three days of "poor" eating with one day of "great" eating (we feed them ad libitum--never force them to finish their plate). But I'm not sure about the whole macronutrient bit since they eat what we feed them. Interesting thoughts.
Keep up the good work.
One of the great things about a paleo diet:
Low calorie density (by weight) with high nutrient density (by calorie).
The other thing we need to look at is nutrition density,(nutrition/calories) to make the decision if there is anything besides calories in the food. Sugar, grains, and oils are so low that we should not eat them.
You noted that "tricking" satiation won't really help you if you're not eating as much as you actually need, since you'd just be hungry a little bit later.
I wonder about the opposite effect. If you eat more than you need, but eat well, and store it up, as long as you're able to access that storage you shouldn't be hungry for a longer time.
So as long as you're able to consume that and you don't eat again before you're actually hungry, it shouldn't be so much of a problem. I guess there might be some nutrient that doesn't translate as well or you can't easily keep so there's still a net excess, although the time interval wouldn't be that big.
But still, I feel being able to functionally burn stored calories is at least as important as matching satiation and satiety, not that the discussion about it isn't very relevant, specially when you're trying to explain why obesity occurs and "grows".
Something else that came to my mind as I read is how used to cooking and adapted to it we are. I think it's still a bit open just how long ago people started to cook, but it should be at least close to a couple hundred thousand years and (pure guess here, but I think it makes sense) maybe much more, so it probably had at least some effect on us.
Oh, about fat, usually when I'm having meat I eat all the fat I can. When I have plenty, maybe in an all you can eat or a barbecue, as I start to "fill up" fat gets less attractive much faster than meat otherwise. It gets to a point in which I can easily have more steak but just thinking about eating that big piece of fat makes me uneasy.
I'm not sure how that works for other people but it seems to me even if a certain food has more calories per gram than another one, even after accounting for water intake or chewing time, such food might still not take as much longer as one might predict to get you to satiation, through other mechanisms.
Stanton, thank you, this series has been a great source of information.
I have noticed that some bloggers add a $2 paypal button at the bottom of each entry, labeled something like "if you liked the post, you can invite me to a cup of coffee". It is not a bad idea (I think) since, after all, reading your blog is not unlike when I treat a friend to a coffee/beer/etc in order to pick his brain on a specific subject he is knowledgeable on.
Again, thank you.
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