(Part V of a series. Go back to Part I, Part II, Part III, or Part IV—or skip to Part VI.)
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 body composition.
- Restrained eating requires the exercise of willpower to override likes, wants, and the lack of satiation or satiety; the exercise of willpower uses energy and causes stress; and stress makes you eat more. Therefore, a successful diet must minimize the role of willpower.
- A lack of satiety will leave us hungry no matter what else we do to compensate. We fail to achieve satiety by not ingesting (or not absorbing) the energy and/or nutrients our body requires, and by an inability to retrieve the energy and/or nutrients our bodies have stored due to mitochondrial dysfunction.
Satiation vs. Satiety, Satiated vs. Sated: Understanding The Differences
In common use, “satiation” and “satiety” are basically synonyms. Even the scientific literature does not always maintain or respect the difference, so it’s important to understand and distinguish exactly what’s being discussed.
Satiety is your body’s response to the availability of nutrients from food that you’ve already digested and processed. (We discussed satiety at length in Part IV.)
Satiation is your immediate reaction to the ingestion of food—the drive that causes you to stop eating. It is your body’s attempt to estimate future satiety via sensory input: smell, taste, texture, and stomach distention.
I’ve quoted this passage before, but I’ll quote it again, because it’s important:
Nutrition Bulletin Volume 34, Issue 2, pages 126–173, June 2009
Satiation, satiety and their effects on eating behaviour
B. BenelamSignals about the ingestion of energy feed into specific areas of the brain that are involved in the regulation of energy intake, in response to the sensory and cognitive perceptions of the food or drink consumed, and distension of the stomach. These signals are integrated by the brain, and satiation is stimulated.
When nutrients reach the intestine and are absorbed, a number of hormonal signals that are again integrated in the brain to induce satiety are released.
It’s difficult to draw a sharp line between satiation and satiety: some foods digest very quickly, and their nutrients are available quickly enough for satiety to affect the satiation response. (Example: simple sugars and carbohydrates, whey protein isolate.) And there is strong support for the idea that taking longer to eat results in lower food intake, probably because the satiety response begins to come into play.
Satiation Is Relative To Satiety
Since satiation is an attempt to predict (via sensory input) future satiety (i.e. nutrient absorption), it should be obvious that our current state of satiety affects what foods we find satiating—or not satiating. Here’s an interesting example of this effect:
J. Nutr. January 1, 1998 vol. 128 no. 1 61-67
Prior Day’s Intake Has Macronutrient-Specific Delayed Negative Feedback Effects on the Spontaneous Food Intake of Free-Living Humans
John M. de CastroFood energy intake during a day was found to only mildly affect intake on the subsequent day (mean r = −0.07, P < 0.001), but was more strongly negatively related to intake occurring on the second (mean r = −0.18, P < 0.001) and third day (mean r = −0.10, P < 0.001) afterward.
Each macronutrient was shown to have a maximal negative relationship with subsequent intake of that same macronutrient, with 2-d lag mean autocorrelations equal to −0.11, P < 0.001 for carbohydrate, equal to −0.18, P < 0.001 for fat, and equal to −0.13, P < 0.001 for protein. These effects on daily intake were found to result from separate negative feedback effects on meal size and frequency.
Stated plainly: not only does eating more food cause you to eat less food 2-3 days afterward—eating more protein, fat, or carbohydrate causes you to eat less of the same 2-3 days afterward. Here are the graphs:
The effect is not large, but it is consistent and significant.
And though deCastro didn’t graph meal size and frequency, they were also compensated for with a 2-3 day time lag.
There are some studies that claim to show macronutrient compensation doesn’t exist—but they examine only the next meal eaten on the same day, or perhaps the morning after.
This is only one example of satiety affecting satiation, but I think it proves the point: satiation is relative to your current state of satiety. (For another real-world example of the effects of previous meals on satiety, see the study referenced in my classic article How “Heart-Healthy Whole Grains” Make Us Fat.)
We’re all familiar with the manifestations of this effect. For instance, after two weeks of living primarily on bento boxes and bowls of ramen while in Japan, my friend and I found ourselves absolutely craving red meat—and we proceeded to draw a crowd of spectators at an all-you-can-eat yakiniku restaurant, by eating more than any of them had probably seen consumed at once by anyone but a sumo wrestler.
Yakiniku = grill your own meat, at your own table. Basically Korean BBQ without the kimchi.
How Satiation Fails: Bypassing Sensory Input
Since satiation is dependent on sensory input, it seems logical that we can break satiation by bypassing or attenuating the sensory experience of eating.
This is, in fact, the case.
It has been known for a long time that the obese eat more quickly than the non-obese:
Int J Obes. 1977;1(1):89-101.
Eating in public places: a review of reports of the direct observation of eating behavior.
Stunkard A, Kaplan D.…Two measures showed promise in discriminating obese from non-obese persons. The first was food choice: obese persons chose more food than non-obese persons (and men chose more than women and tall persons more than short ones). The second measure was rate of eating: obese persons consumed more food per minute than non-obese persons.
Further reading: Psychosom Med Vol. 42, No. 6
Eating Style of Obese and Nonobese Males
Kaplan D
And under controlled conditions, people eat more when they are allowed to eat quickly than when their eating rate is restricted:
Am J Clin Nutr August 2009 vol. 90 no. 2 269-275
Effect of bite size and oral processing time of a semisolid food on satiation
Nicolien Zijlstra, René de Wijk, Monica Mars, Annette Stafleu, and Cees de GraafResults: Subjects consumed significantly more when bite sizes were large than when they were small (bite size effect: P < 0.0001) and when OPT [oral processing time] was 3 s rather than 9 s (OPT effect: P = 0.008). Under small bite size conditions, mean (±SD) ad libitum intakes were 382 ± 197 g (3-s OPT) and 313 ± 170 g (9-s OPT). Under large bite size conditions, ad libitum intakes were much higher: 476 ± 176 g (3-s OPT) and 432 ± 163 g (9-s OPT). Intakes during the free bite size conditions were 462 ± 211 g (free OPT), 455 ± 197 g (3-s OPT), and 443 ± 202 g (9-s OPT). Conclusion: This study shows that greater oral sensory exposure to a product, by eating with small bite sizes rather than with large bite sizes and increasing OPT, significantly decreases food intake.
Many food choices can increase our rate of eating. We can eat liquid foods more quickly than solid foods, soft foods more quickly than hard foods, tender foods more quickly than tough foods.
For instance, “meal replacement shakes”, being liquid, don’t produce the same satiation response as eating real food:
Journal of Comparative and Physiological Psychology Volume 68, Issue 3, July 1969, Pages 327-333 doi:10.1037/h0027518
Preloading and the regulation of food intake in man
Barbara C. Walikea, Henry A. Jordan and Eliot Stellar“17 human Ss [Ss = subjects] ate 20-min meals of Metrecal through a straw connected to a hidden reservoir. Oral preloads of Metrecal were administered before the meals, and these varied 20-120% of the amount of the base-line meal intake and were given 1-120 min. before the meal. Test-meal intake was depressed as a function of the size of the preload; however, the Ss did not take the preload fully into account and they overate.”
Note: Metrecal started the 1960s craze for meal replacement shakes. Its ingredients: “A mix of skim-milk powder, soybean flour, corn oil, minerals and vitamins.” (More information here.) It is also claimed that Metrecal tasted absolutely terrible—though since it hasn’t been produced since the 1970s, there’s no way to know for sure.
And people eat more yogurt when they can suck it through a straw than when they have to use a spoon:
Am J Clin Nutr April 2010 vol. 91 no. 4 841-847
Intake during repeated exposure to low- and high-energy-dense yogurts by different means of consumption
Pleunie S Hogenkamp, Monica Mars, Annette Stafleu, and Cees de GraafResults: Intakes (P = 0.01) and eating rates (P = 0.01) were highest in the liquid/straw group. Average intakes over 10 exposures were 575 ± 260 g for liquid/straw, 475 ± 192 g for liquid/spoon, and 470 ± 223 g for semisolid/spoon; average eating rates were 132 ± 83 g/min for liquid/straw, 106 ± 53 g/min for liquid/spoon, and 105 ± 88 g/min for semisolid/spoon.
Conclusions: We observed no energy intake compensation after repeated exposure to yogurt products. Differences in ad libitum yogurt intake could be explained by eating rate, which was affected by the different means of consumption.
From this, we can see that it’s easy to bypass our satiation response by eating highly processed foods. Processing (and cooking) basically pre-digests food for us, which increases both the speed at which we can eat it and the speed at which we can absorb it.
Even the toughest, stringiest cut of modern beef is from an animal that has never had to run from predators…and it’s been ‘aged’ for at least two weeks, which is to say that it’s been left to slowly rot in its own digestive enzymes in order to make it softer and more tender.
Thought experiment: consider the rate at which you could hack meat and fat off of a fresh bison carcass using sharp rocks, and the rate at which you could chew and swallow that raw meat—versus the speed at which you can gobble down medium-rare hamburger or prime rib.
Finally, I’ll note that an increasing cultural tendency to “eat on the run” increases our rate of food ingestion. Gobbling down food in a hurry because we need to get back to work, or pick up the kids, or get our shopping done, seems likely to cause us to eat more regardless of what we’re eating—and taking the time to savor our food and enjoy the process of eating is likely to cause us to eat less, again independently of what we’re eating.
Not an environment that encourages savoring food.
It's called 'fast food' for excellent reasons.
It is also most likely the case that eating while distracted—watching TV, working, driving—attenuates the sensory experience of eating, and thereby the satiation response. (Hat tip to alert commenter JKC.) There is much more to investigate here.
Stomach Distention: Necessary But Not Sufficient
Finally we turn to stomach distention: the sensation of being “full”.
I’ve saved the best part for last…so keep reading!
A lot of noise has been made about how “energy density” is the key to dieting—usually by low-fat apostles who never fail to recite the fact that protein and carbohydrate have roughly four calories per gram, whereas fat has about nine. The same theory lies behind the Volumetrics Diet, which pushes high-bulk, low-fat foods as the key to weight loss—and it drives our medical establishment to perform tens of thousands of lap-band surgeries and gastric bypasses every year.
Unfortunately, feeling “full” is not the entire story, as we can demonstrate by one simple fact: if it were, all anyone would need to lose weight is a giant jar of sugar-free Metamucil. Now that we’ve solved the obesity problem, we can all go home, right?
Well, no. As I explained back in Part II, you can fake satiation, but you can’t fake satiety. Eating extremely energy-dense foods can indeed cause us to overeat…but if we’re not getting the energy and nutrients we need, consuming more water and eating more indigestible fiber does not magically make us feel satiated or sated.
In support of this, note the long-term results from stomach stapling (VBG, or “vertical banded gastroplasty”) and lap-band surgery:
J Gastrointest Surg. 2000 Nov-Dec;4(6):598-605.
Ten and more years after vertical banded gastroplasty as primary operation for morbid obesity.
Balsiger BM, Poggio JL, Mai J, Kelly KA, Sarr MG.“Weight (mean +/- standard error of the mean) preoperatively was 138 +/- 3 kg and decreased to 108 +/- 2 kg 10 or more years postoperatively. Body mass index decreased from 49 +/-1 to 39 +/- 1. Only 14 (20%) of 70 patients lost and maintained the loss of at least half of their excess body weight with the VBG anatomy. Vomiting one or more times per week continues to occur in 21% and heartburn in 16%.”
Note that the long-term results of lap-band surgery (“gastric banding”) are very similar: “no significant difference in weight loss was registered between the 2 study groups” (Miller et.al.)
While the average patient maintained a 30 kg weight loss, this didn’t get them even halfway to normal weight: only one in five patients managed to maintain this milestone.
Energy Density: It’s Not The Fat, It’s The Water
Clearly low energy density isn’t a panacea—but it does make some difference to satiation. Let’s take a look at the data!
Besides protein, fat, and carbohydrate, foods typically contain “fiber” (indigestible carbohydrate) and water. While the anti-meat, anti-fat brigade concentrates on 9 vs. 4 calories per gram, we need to take into account the fact that meat is comprised primarily of water.
I’ll handicap the comparison by choosing an extra-fatty USDA Prime grade of prime rib, which contains 367 calories per 100 grams, or about 3.7 calories per gram. (Link.)
In contrast, rice cakes contain 392 calories per 100 grams, or almost 4 calories per gram. (Link.) That’s right: rice cakes are a denser source of calories than prime rib!
That’s because rice cakes, like all shelf-stable foods, have most of the water removed in order to preserve them and retard bacterial growth. As a rule, anything you’ll find in a box on the shelf will be dehydrated—and, in consequence, extremely calorie-dense.
Dehydration and Preservation
We’re all familiar with the phenomenon of stored food getting wet and rotting, or going moldy. Since life requires water, one of the best ways to keep food from spoiling is to remove all the water, and seal it to stop water from getting in—thus preventing bacteria from growing on or in it.
For instance, pemmican is just meat with all the water removed: the fat is separated from the meat and boiled to remove the water, while the meat is air or oven-dried and ground into bits.
Here are some “calories per 100 grams” readings for common “healthy” packaged foods—
—all of which are more calorically dense than prime rib!
- Cheerios: 367 kcal/100g
- Fruit roll-ups: 371 kcal/100g
- Fat-free potato chips: 379 kcal/100g
- Rice Chex: 382 kcal/100g
- Air-popped popcorn (yes, the nasty dry stuff): 387 kcal/100g
- Kellogg’s low-fat granola bar: 390 kcal/100g
- Kashi Organic Promise Cranberry Sunshine cereal: 401 kcal/100g
- “Low-fat” tortilla chips: 416 kcal/100g
- Soy “nuts”: 451 kcal/100g
- Tortilla chips: 492 kcal/100g
- Potato chips: 547 kcal/100g
- Oil-popped microwave popcorn: 583 kcal/100g
- Dry-roasted peanuts: 585 kcal/100g
In contrast, here are some statistics for whole paleo foods commonly derided as “rich”, “heavy”, and “fattening”:
- Sauteed yellow onions: 132 kcal/100g
- Hard-boiled egg: 155 kcal/100g
- Hash browns in butter sauce: 178 kcal/100g
- Fried egg: 196 kcal/100g
- Beef chuck blade roast: 248 kcal/100g
- Bacon: 459 kcal/100g. OK, I admit it: we’ve finally found something 14% more calorie-dense than Kashi Organic Promise Cranberry Sunshine.
Furthermore, as long as we’re talking about water, we must take into account the water we consume along with the food we eat. Some studies claim that oatmeal is the most satiating food in the world—but if you don’t allow people to drink, a food made with mostly water will be more ‘filling’ than a drier food, even if the real-world result would be equal bulk due to the drier food making you more thirsty.
A Speculative Hypothesis About Water Intake
Since we require water in order to process salt, it might very well be that a low-salt diet causes decreased water consumption and a parallel decrease in satiation during real-world meal consumption. A similar situation might also occur with bland vs. spicy food: increased water intake with spicy food might result in greater satiation.
If anyone knows any research that addresses this issue, please let me know. Most studies don’t allow or record ad lib water consumption, and therefore aren’t much help.
(It is also the case that it takes more time to chew and eat a less calorically dense food than a more calorically dense food…so density most likely affects eating rate as well as gastric distention. And how much do you have to chew a steak, versus breakfast cereal?)
Finally, we address the standard bulking agent: “fiber”. Most of the controlled studies on fiber address the “heart-healthy” claims and focus on blood lipoprotein levels, but this review conveniently summarizes the available literature relating to weight loss:
Gastroenterology. 2010 January; 138(1): 65–72.e1-2.
Dietary Fiber Supplements: Effects in Obesity and Metabolic Syndrome and Relationship to Gastrointestinal Functions
Athanasios Papathanasopoulos, M.D. and Michael Camilleri, M.D.Recent meta-analyses of randomized controlled studies (RCTs) suggest only minor effects on weight loss for commonly used DF supplements.
Conveniently, Table 3 lists the studies and their findings—and a quick reading shows that the studies whose only intervention was additional fiber resulted in zero or insignificant weight loss, whereas the studies that resulted in significant weight loss were compound interventions of which fiber was only one small component.
Conclusion: How We Break Satiation
- Since satiation is an estimate of future satiety based on sensory input, much of satiation is driven by our body’s nutritional needs, and the factors that affect satiety will also affect satiation.
- Therefore, we can fail to achieve satiation by eating nutritionally incomplete foods, with no protein (or incomplete protein) and few nutrients.
- Since satiation is dependent on sensory input, we can fool satiation by decreasing sensory exposure to our food—or otherwise attenuating the sensory experience of eating.
- We can do this by eating quickly, which we usually accomplish by eating food in liquid or other highly processed (and, therefore, pre-digested) forms. It is also likely that caloric density enables quicker eating to some degree.
- Cultural factors may also play a role in satiation. A culture that treats eating as an inconvenient obstacle to accomplishment, rather than an experience to be savored, seems likely to decrease our sensory exposure to food by eating quickly (“on the run”) or while distracted, thereby reducing satiation and encouraging overconsumption.
- Decreased caloric density also increases satiation, to a degree—but it is primarily driven by water content, not by calories per gram of macronutrient. Packaged foods are typically far more calorie-dense than whole, fresh foods due to dehydration.
- Dietary fiber may increase satiation—but since it has no significant effect on long-term weight loss, it clearly has no effect on satiety.
Continue to Part VI: Hedonic Impact (“Liking”), Incentive Salience (“Wanting”), and “Food Reward”: Why Are We Hungry? Part VI
Live in freedom, live in beauty.
JS
(Part V of a series. Go back to Part I, Part II, Part III, or Part IV.)
Did you find this article surprising or illuminating? Yes, you did, because you didn’t know that prime rib is less calorically dense than rice cakes.
You can support my continued efforts to inform, educate, and amuse you by buying a copy of my “Funny, provocative, entertaining, fun, insightful” novel The Gnoll Credo. US residents can buy signed copies directly from my publisher, Barnes and Noble offers free shipping to the USA, and it’s available worldwide, with free shipping, through (EDIT: link fixed) The Book Depository.
(Yes, you can still buy it through Amazon.com, but they’re taking at least a week to ship.)
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.
John:
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.
Samantha:
Most importantly, almost all shelf-stable foods are more nutritionally dense than prime rib, due to the dehydration.
Jan:
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!
JKC:
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.
Chandra:
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?”
Timothy:
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
small intestine.
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.
M:
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!
JS
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”.
Slainte mhaith.
Jacquie:
We've got several installments to go yet.
Franco:
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.
Jim:
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.
JS
LeonRover:
Thank you!
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,
JS
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.
Good read.
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.
Stipetic:
Yes, I eat Greek yogurt reasonably regularly. I don't have a problem eating it quickly…but I don't want very much of it, either.
I don't take the macronutrient cycling as a primary driver of anything, because the effect is small. Mainly I'm trying to demonstrate that satiety is relative to our current nutritional state. That being said, candy and soda will never be satiating, because they contain no nutrients.
Interestingly, now that you mention it, I definitely eat more monotonously now that I'm eating very nutrient-dense food (see: the Paleo Scramble and its variants). It's back when I was still eating the SAD that I'd get cravings for random foods and go through “phases” of eating lots of one thing, probably because I was cycling between foods that were deficient in one thing or another. Now I'm happy to eat basically the same things week-to-week. I hadn't thought about this before, but it definitely supports the theory that satiety is primarily nutrient-driven.
Good to see you here! I hope you'll stay and keep contributing.
Kit Perkins:
Absolutely. This is especially important if you're trying to lose weight, because you're eating less food but your body still needs nutrients…so the nutrient density must increase.
As I've said before, the problem isn't that food is rewarding: it's rewarding taste without the nutrition that has accompanied it through evolutionary time. Our taste buds are not trying to make us fat: they're trying to make us eat right. Over the millions of years of human and pre-human evolution, anyone whose tastes did not correspond with healthy eating would be outcompeted by those whose tastes drove them to eat the most healthy food possible.
fredt:
Exactly! That's a great way of thinking about “should I eat this food”…what's the nutrition to calories ratio? The worst foods (like gluten grains) actually decrease the nutrition of what you eat with them by disrupting digestion and containing antinutrients.
Fmgd:
Definitely…you ought to be able to store food and retrieve it later. That's what IFing is about: eating big meals and then letting yourself run on the stored energy. The problem is, as I explained in Part IV, obesity generally comes with mitochondrial dysfunction — an inability to access the energy we've stored.
As far as cooking, you're about right: the earliest solid evidence for control of fire is about 250,000 years ago (earlier dates are sometimes claimed, but the evidence is ambiguous and not widely accepted AFAIK), and its effect on our evolution is a whole article in itself!
“…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.”
Recall that satiation is driven by satiety. If you've already eaten a bunch of steak that day, steak will most likely satiate you more quickly at dinner because your body doesn't need more…whereas if you've been stuck eating noodles and bento for two weeks, as I was in Japan, meat was not satiating until I couldn't physically cram any more into my stomach.
I appreciate your thoughts.
Txomin:
I'm honored.
If you want to tip me, the best way is to buy a copy of The Gnoll Credo from the links on the right sidebar…and to buy direct from the publisher if you're in the USA. (Already have one? Gift one to a friend!) You can also make your Amazon purchases through the link in the right sidebar, which gives me a referral spiff without increasing your cost at all.
JS
@Fmgd,
yep, I’m the same with barbecues and such things. First eat the fatty cuts, then the lean.
Also, fatty sauces are much more appealing at the start.
What is your take on Seth Roberts’ flavorless calories stuff?
Michael:
I started writing a response…but it got longer and longer, and I realized it really needs to be part of the upcoming articles in which I address liking and wanting. So you'll have to wait for it.
However, its effect is indeed explainable in terms of the four hunger motivations, as we should expect. It is important to note that I am NOT attempting to advance a new theory of hunger or weight loss with this series! I'm explaining the current state of scientific knowledge as best I can, with an aim towards using that knowledge to answer some important questions.
JS
“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.”
Soft drinks are buffers. I always used to want a Coke with my pizza or other snacky processed foods. Without the buffer, the acid builds up causing heartburn. Eating bad (corn chips and ice cream are my usual cheats), is usually followed by a soft drink later to settle everything down. Otherwise, I don’t want them at all.
hey JS,
looks like Jamie Scott found something very interesting about what we did discuss above (SAFA vs. PUFA and satiation):
http://thatpaleoguy.blogspot.com/2011/09/fatty-acid-signal-transduction-why-your.html#comments
Kris:
I wanted a Coke just to keep me awake…otherwise pizza made me fall asleep. I think there are a lot of different motivations involved.
Definitely the dehydrated foods require more liquids…and if you're in a situation where you're buying Cheetos, you're also likely to buy a Coke, considering that at most convenience stores soda costs less than water. Note the synergistic effect: dehydrated, salty foods make you thirsty, and sodas contain so much sugar that they don't quench thirst very well…
Franco:
Thanks for reminding me! Jamie put up a bunch of posts recently, and as I was out of town, I managed to skim right over that one.
That's a very interesting lead, and it definitely confirms my anecdotal experience: SAFA is more satiating than PUFA. Maybe I'll describe the experiment I did someday.
JS
This series is brilliant, the last two articles I’ve found particularly interesting. Of course, with “prime rib” in the title I was sold before even reading the article. I was always a person that enjoyed, prided myself upon even, eating anything and everything. Food was entertainment, reward, variety and probably a host of other things I’d rather not admit to myself. Now on functional paleo I also eat very monotonously yet there is absolutely no sensation of something lacking. My wife asks me if I ever get tired of eating the same things over and over. But the ribeyes and lamb chops seem to taste just as delicious every time I eat them even though that’s pretty much daily. Reading these articles I think I now understand why that is.
Franco – Living in Russia I occasionally enjoy the indulgence of salo, which is something of an acquired taste. It’s actually on offer in the ski lodges in the Caucuses where I spend much of the winter and is great on a cold day on the mountain. I tend to forgo the vodka, however, as it doesn’t mix too well with skiing.
JL:
I find the same thing…prime rib never becomes tiresome!
You imply a good point: I think the drive for novelty in food is a result of nutritional incompleteness. Our bodies are signaling “Hey, we're short on some important nutrients here, better find something different than you've been eating.” Of course none of the processed “foods” on offer satisfy those nutritional needs, so we bounce around from novelty to novelty, gaining weight yet never being satiated.
JS
Great stuff all around. Of course, what can you expect from someone with the initials “JS”
Re Eating on the run, I must say your conclusion is wrong – people eat fixed portions on the run so its not important how fast they eat they will marely feel satiated with latency. The fattening effect is due to junk food which is what is typicaly used ‘on the run’, loaded with trans fats and carbs.
The same argument goes for the fast eaters in the restoraunt – that means that size is fixed and food is not chewed well and not absorbed good enough. This will reduce sugar spike reducing hyperinsulinemia. See “Swallowing food without chewing; a simple way to reduce postprandial glycaemia” paper.
So, the problem is apperent when you have non fixed food supply and you eat fast. In my country there is a proverb to “stop eating when its a most delicious”. I always thought that is some religious boolshit, but now I see its to account for satiety latency. In my experience, this latency could be as long as 1 hour.
BTW, I really think people need to change their view of fiber as “indigestible carbohydrate”. Since microbiota is now considered separate organ, its anything but not indigestible.
About your “Speculative Hypothesis About Water Intake”, its not only about salt, its about buffering property of the water to HCL so there will be less acid and food will take longer to digest (given that protein is dominant). This may or may not be good thing – lots of water, particularly cold one may stall the digestion for longer time making food to stay in stomach and rot and giving oportunity to stomach bacteria to metabolise it.
majkinetor:
Speed of eating and distracted eating are certainly not the only factors — I'm saying that they're contributing factors. The fact that fast food is generally made of junk is probably the largest contributor…but eating more of it than you might otherwise doesn't help.
I've seen the “Swallowing food without chewing” paper, and it's quite true…but, as this series establishes, there are several competing motivations. Lower GI = more sating, but eating faster = less satiating. If the solution were simple (“don't eat fat”, “eat bulky food”, “eat bland food”) we'd have already found it and there would be no obesity crisis.
As far as fiber, there's soluble and insoluble fiber. Soluble fiber indeed converts to nutrients: insoluble fiber doesn't to any significant extent, by definition.
You raise a good point about water reducing stomach pH and thereby increasing digestion time. Yet another factor to take into account!
Thanks for contributing: if everyone agreed with me on everything, I'd never learn anything.
JS
Why worry about satiation at one meal when research shows you make up for it in other meals. So I was distracted at dinner and ate more? At breakfast I’ll likely be less hungry. The body has a set point and maintains it. You can’t fool it long term with tricks like more or less water, watching tv or whatever. So why worry about it? Eat the way that makes you happy and relaxes you. Could be that cortisol might effect set point so don’t get all stressed out LOL!
Eva:
Actually, the research seems to say that while lean people typically compensate for overeating by later undereating, obese people usually don’t.
And there’s no such thing as a “set point”, or we’d find gaining weight just as hard as losing it! The body is an incredibly complex web of interacting homeostases. What people call a “set point” is just the fact that we can’t usually just change one tiny element for a short period of time and cause the entire system to reconfigure.
JS
[…] Stanton, J. (2011). When Satiation Fails: Calorie Density, Oral Processing Time, and Rice Cakes vs. Prime Rib (Why Are We Hungry? Part V). Gnolls.com. Retrieved September 13, 2011. http://www.gnolls.org/2472/when-satiation-fails-calorie-density-oral-pro…. […]
[…] meal. Chewing also tells your brain how much you’ve eaten, working with your senses to help regulate satiation and predict satiety. When calories are taken in liquid form, your body doesn’t register what it has just […]
J,
This series, especially this piece in the series, inspired my new YouTube video.
Just wanted to thank you for the work you’ve done which has been a big inspiration for me generally.
Regards,
Daniel
https://www.youtube.com/watch?v=9FnxTPjT1Uc