Nutrition Guide · Satiety and protein

Full is a signal: satiety, protein and your body

Your body reports when enough is enough. The question is not whether it sends. The question is whether the line is clear or whether modern meals drown the signal out.

SJ
Shukri Jarmoukli · Physician, Integrative Medicine · ViveCura Berlin
Satiety physiology Protein leverage Biofeedback 32 studies with DOI
Why I'm writing this

People sit in my consulting room all the time believing they lack discipline. I see it differently. Most of the time the will is perfectly intact. What is missing is a signal that arrives loudly enough. And messages can be disturbed.

You have eaten. The plate is empty. And twenty minutes later you are standing in front of the fridge, not quite sure why.

Or you know the other version. Breakfast at eight, a roll with jam, a coffee. By half past ten you can think of nothing but the cookie in the drawer. The day before, after scrambled eggs and quark, food did not cross your mind until lunch.

Same person. Same will. Different signal.

I want to show you that satiety is not a character trait, it is a messaging system. Your gut sends, your nervous system passes it on, your brain does the math. How loudly the message arrives depends on things you can influence.

What to expect here

  • Why fullness is a message, not an act of will
  • Who reports in and when: ghrelin, CCK, GLP-1, PYY
  • The line to the brainstem along the vagus nerve
  • The protein leverage hypothesis with its numbers
  • Why industrial food dilutes protein
  • The Satiety Index: potato versus croissant
  • Pace, liquid calories, screens, sleep
  • Why strict rules can replace your own perception
  • Thirteen common questions on the topic
Clinical RCT or meta-analysis in humans Human Observation or measurement in humans Mechanism Review and physiology

Feeling full is a message, not a character trait

Ask yourself honestly: when were you last full and content, without having to talk yourself into it?

Many people experience fullness today as something they have to produce. As an act of will. Physiologically that is a surprisingly wrong description.

Your body has its own reporting system for this job. Picture a two way radio: down in the belly the transmitter, up in the brainstem the receiver. Fullness arises where the message lands.

Research distinguishes two things here, and that distinction explains a lot. One is the satiation that ends a meal. The other is the satiety that delays the next hunger.

Mechanism What can actually be measured about satiety

A Dutch group around Cees de Graaf collected which measurable quantities relate to appetite and food intake.

For the end of a meal, stomach stretch as well as CCK and GLP-1 in the blood count as usable markers, for the longer satiety afterwards it is short term drops in blood sugar, leptin across days, and ghrelin.

For you this means: one signal makes you put down the spoon. The other decides whether you think about the cookie at half past ten.

de Graaf C et al. Am J Clin Nutr. 2004;79(6):946-61. DOI: 10.1093/ajcn/79.6.946

The general introduction to hunger and satiety hormones is in Appetite, hunger and satiety. Here we go one step further, namely to the strength of the signal itself.

Reframe

The sentence is not: I lack discipline. The sentence is: the message arrives too quietly in me.

That is not consolation, it is a better description. Discipline is hard to turn up. The volume of a signal is easier.

And now you know why the next question is: who is sending, exactly?

The senders: who reports in from your gut

Do you know the feeling that hunger arrives on time? Almost to the minute. That is not habit alone, that is chemistry with a schedule.

1

Ghrelin from the stomach: the start signal

Ghrelin rises before meals and falls afterwards. It reports emptiness, not desperation.

2

Stretch receptors: the volume

Mechanosensors in the stomach wall report fullness, not calories. That is why a plate of soup fills you differently than a bar with the same energy.

3

CCK from the duodenum: fat and protein have arrived

When fat and protein reach the upper small intestine, cholecystokinin is released. It can slow down gastric emptying.

4

GLP-1 and PYY from the lower small intestine: the ileal brake

When nutrients arrive far down in the small intestine, a particularly strong stop signal can travel upwards.

5

Leptin and insulin: the long term report

They do not report the meal, they report the reserves. Across days, not across minutes.

Clinical A single gut hormone lowers the portion

A London group around Rachel Batterham gave twelve people with obesity and twelve lean people the gut hormone PYY3-36 as an infusion, double blind, two hours before a buffet.

Calorie intake fell by 30 and 31 percent respectively. The body's own PYY levels were lower in obesity.

For you this means: the receptiveness to the signal was apparently intact. What was less available was the signal itself.

Batterham RL et al. N Engl J Med. 2003;349(10):941-8. DOI: 10.1056/NEJMoa030204
Clinical Why the sweet breakfast asks for a second round

A group around Karen Foster-Schubert had 16 healthy people drink isocaloric beverages, made up mainly of carbohydrate, protein or fat.

Across the whole time course, protein dampened the hunger hormone ghrelin most strongly. In the first three hours carbohydrate was ahead, and afterwards it was the only one to rebound above baseline.

For you this means: the hole in the late morning is measurable. Protein dampens more flatly, but for longer.

Foster-Schubert KE et al. J Clin Endocrinol Metab. 2008;93(5):1971-9. DOI: 10.1210/jc.2007-2289 · Cummings DE et al. Diabetes. 2001;50(8):1714-9. DOI: 10.2337/diabetes.50.8.1714

How leptin and insulin steer weight regulation across weeks is described in Leptin, insulin and weight regulation.

Reframe

Your hunger is not a character flaw. It is a calendar made of hormones, timed by what you ate before.

And now you know why the sender alone is not enough. A message needs a line.

The line: from gut to brainstem

Imagine someone calling up to you from the basement while the washing machine is spinning upstairs. It was sent. Nothing arrived anyway.

This part gets discussed less often than the hormones themselves. There is a line, and it has a volume dial.

That line is largely the vagus nerve. It runs from the gut into the brainstem and ends there in the nucleus tractus solitarii. From there it continues into the hypothalamus, where the message is set against the long term data from leptin and insulin.

Mechanism The gut sends without pause

Hans-Rudolf Berthoud summarized the reporting direction of gut brain communication, meaning the path from the bottom upwards.

The gut continuously sends information about the amount and quality of food upwards, through hormones like ghrelin, GLP-1 and CCK and through numerous vagal mechanosensors.

One side finding has occupied me for years: the stream of signals can also create the feeling of contentment after eating. Full and content sit next to each other physiologically.

Berthoud HR. Neurogastroenterol Motil. 2008;20 Suppl 1:64-72. DOI: 10.1111/j.1365-2982.2008.01104.x

The line does not simply pass things on, it weights them. Sensory vagal neurons carry messenger substances that can amplify or dampen the signal. Even the body's own GLP-1, that messenger with the current pharmacological career, appears to unfold its influence on eating behavior mostly along this route. How the brain finally does the math on the message is still not settled. The author of the leading review says so himself.

Reframe

A strong signal on a disturbed line arrives just as poorly as a weak signal on a clear one. Both count.

That is why it is rarely enough to simply eat more protein and leave everything else as it is.

And now you know why the loudest sender in this system comes next.

The protein lever: you eat until the protein adds up

There is one idea about satiety that floored me the first time I read it. It does not come from nutritional medicine, it comes from nutritional ecology.

The thesis of Stephen Simpson and David Raubenheimer goes roughly like this: humans do not regulate towards calories, they regulate towards an absolute amount of protein. And keep eating until that amount has come together.

Something uncomfortable follows from that. If you dilute protein in the food, the total amount should rise. Not because someone gets weak, but because an account stays open.

The lever as a picture

The dark block is the amount of protein your body regulates towards. It stays the same size in all three rows. The smaller the protein share, the longer the row has to become.

25 percent protein short row
Protein
Rest
15 percent protein typical average
Protein
Rest
10 percent protein heavily diluted
Protein
Rest

A model with complete compensation. In reality the body compensates incompletely: in a controlled trial, energy intake rose by 12 percent at 10 instead of 15 percent protein, not by the 50 percent the arithmetic would demand.

Clinical The direct test in humans

An Australian group around Alison Gosby had 22 lean people spend three four day phases with 10, 15 or 25 percent of energy as protein, with taste matched and amounts free.

Lowering from 15 to 10 percent raised total energy intake by 12 percent, mostly through savory snacks. Raising it to 25 percent changed nothing.

For you this means: the extra typically lands in the snack, not in lunch.

Gosby AK et al. PLoS ONE. 2011;6(10):e25929. DOI: 10.1371/journal.pone.0025929
Clinical Across 38 studies

The same group then analyzed 38 feeding studies in which people ate as much as they wanted.

The protein share was negatively related to total energy intake, in lean and in people with obesity alike. Whether carbohydrate or fat played the diluter made no difference.

What that means: it appears to be the missing protein share that pushes the amount upwards.

Gosby AK et al. Obes Rev. 2014;15(3):183-91. DOI: 10.1111/obr.12131
Clinical Twelve weeks without counting

David Weigle and his team in Seattle had 19 people eat as much as they wanted for twelve weeks, with 30 instead of 15 percent protein.

Spontaneous energy intake fell by 441 kilocalories per day, body weight by 4.9 kilograms. And that although leptin fell and ghrelin rose, so the hormones pulled in the opposite direction.

For you this means: nobody counted, nobody held back. The amount fell by itself. One obvious explanation is the louder signal.

Weigle DS et al. Am J Clin Nutr. 2005;82(1):41-8. DOI: 10.1093/ajcn.82.1.41

Now the part that honesty demands. The lever is not symmetrical. In a Dutch crossover study with 79 participants, a high protein phase clearly lowered energy intake. For the low protein step, though, the same study found no evidence for protein leverage. And a large review notes: acute studies show a moderate satiety effect, but no reliable effect on the meal that follows immediately.

plus 12 % energy intake at 10 instead of 15 percent protein
441 kcal less per day at 30 instead of 15 percent protein, without counting
38 studies with the same relation to total energy
Reframe

Perhaps your body does not count calories at all. Perhaps it counts protein. That turns a question of self control into a question of composition.

And now you know why the next question is: where does protein get diluted?

Diluted protein: the lever in the supermarket

The protein leverage hypothesis sounds like a laboratory. It actually sits in your ordinary weekly shop.

Protein is the most expensive of the three big nutrients. Anyone making food cheap and shelf stable almost inevitably dilutes the protein share. That is not a conspiracy, that is economics.

Human The dilution in real diets

A group around Euridice Martínez Steele analyzed representative dietary records from 9,042 people in the USA and sorted them by the share of ultra-processed foods.

From the lowest to the highest fifth, the mean protein share of the diet fell from 18.2 to 13.3 percent. The absolute amount of protein in grams stayed fairly constant, while total energy rose.

For you this means: exactly the pattern the hypothesis predicts shows up in the ordinary supermarket diet.

Martínez Steele E et al. Public Health Nutr. 2018;21(1):114-124. DOI: 10.1017/S1368980017001574
Clinical The inpatient trial that matches everything

Kevin Hall and his team at the US National Institutes of Health had 20 adults live on a ward for four weeks, two weeks each on ultra-processed and unprocessed food, matched for calories offered, energy density, sugar, salt and fiber.

On the ultra-processed diet, the same people ate 508 kilocalories per day more. The difference explicitly did not come from protein.

What that means: the fact that the extra did not come from protein is exactly what the protein lever predicts.

Hall KD et al. Cell Metab. 2019;30(1):67-77.e3. DOI: 10.1016/j.cmet.2019.05.008

The general critique of processed foods is in Unprocessed food and satiety, the limits of the plain calorie count in Calories: quality instead of quantity. Here it is only about the dilution.

Reframe

It is not the ready meal as such that makes you hungry. The dilution can make you hungry. A ready meal with a decent protein share behaves differently from one without.

And now you know why two plates with the same calorie count can lead to two different afternoons.

Potato versus croissant: same calories, different fullness

An experiment from 1995 still strikes me as one of the most instructive in nutrition research. An Australian group around Susanne Holt served test groups of eleven to thirteen people isocaloric portions of 38 foods, roughly 240 kilocalories each, and asked about fullness for two hours. White bread served as the reference point at 100 percent.

FoodSatiety indexWhat it brings along
Boiled potatoes323Plenty of water, plenty of weight, low energy density
Fish225Protein pure, little fat
Porridge209Viscous fiber, water, volume
Oranges202Water, fiber, chewing time
Apples197Water, fiber, chewing time
Wholegrain pasta188Fiber, slower eating
Beef176Protein, long chewing time
Popcorn154Lots of volume at little weight
Eggs150Protein and fat
White bread100Reference point of the study
Ice cream96Fat, sugar, slips through fast
Cake65Fat, sugar, high energy density
Croissant47Fat, little water, very palatable

A selection from 38 tested foods, white bread = 100. Between potato and croissant lies roughly a factor of seven, at an identical calorie count. Source: Holt et al. 1995, PMID: 7498104. [Human Study, 38 foods]

More interesting than the ranking is which property tipped the scales. Fullness related most strongly to portion weight and water content, then to fiber and protein. It related negatively to fat content and, this is the uncomfortable part, to palatability as well.

With fiber a refinement is worth making. A systematic review sorted them by their physical properties. Viscous fibers such as pectins, beta-glucans from oats or guar gum lowered appetite in 59 percent of comparisons, less viscous ones in only 14 percent. The authors emphasize at the same time that the effects were small overall.

Clinical Volume as a starter

Julie Flood and Barbara Rolls invited 60 people to lunch once a week for five weeks, with or without soup as a starter.

The soup lowered the total energy of the meal by 20 percent, on average 134 kilocalories. Whether pureed or chunky made no difference.

For you this means: it is not the texture that counts, it is amount and timing.

Flood JE, Rolls BJ. Appetite. 2007;49(3):626-34. DOI: 10.1016/j.appet.2007.04.002 · Wanders AJ et al. Obes Rev. 2011;12(9):724-39. DOI: 10.1111/j.1467-789X.2011.00895.x
Reframe

That highly palatable food fills you less well is not a moral verdict. It is a measurement. A croissant is not a character test, it is a food with little satiety signal per calorie.

And now you know why composition is only half the story. The other half is called pace.

Pace and interference: what turns the signal down

Do you remember the last time you ate standing up? Four minutes, between the door and the next appointment. Afterwards something was missing, even though the plate was empty.

The pace: kilocalories per minute

A group around Ciarán Forde pooled data on 327 foods. The energy intake rate was 35.5 kilocalories per minute for unprocessed foods and 69.4 for ultra-processed ones. So in the same eating time you may have eaten almost twice as much before a signal arrives.

Clinical The same meal at two speeds

A group around Alexander Kokkinos had 17 healthy men eat the same test meal once in 5 and once in 30 minutes.

The responses of the satiety hormones PYY and GLP-1 came out clearly higher after the slow meal. For the hunger hormone ghrelin there was no difference.

For you this means: it is not about suppressing hunger, it is about making the stop signal louder.

Kokkinos A et al. J Clin Endocrinol Metab. 2010;95(1):333-7. DOI: 10.1210/jc.2009-1018

Across 22 studies, eating more slowly went along with lower energy intake, with no relation to hunger afterwards. So less food at the same feeling.

On the famous 20 minute rule: during the research, that number could not be traced back to any primary study measuring it. It is a rule of thumb. The direction holds, the number should not be sold as physiology. Texture counts too: bigger bites and fewer chews lower fullness according to a review, though the author labels the causal link as a hypothesis.

Liquid calories: the bill that never gets sent

Human 118 percent versus minus 17 percent

Deanna DiMeglio and Richard Mattes had 15 people take in the same extra amount of carbohydrate calories over four weeks each, once liquid as soda, once solid as jelly beans.

In the solid phase compensation came to 118 percent, in the liquid phase to minus 17 percent. Body weight and BMI rose only in the liquid phase, and reported hunger did not differ.

For you this means: the juice, the large milky coffee, the beer can largely bypass the satiety system.

DiMeglio DP, Mattes RD. Int J Obes. 2000;24(6):794-800. DOI: 10.1038/sj.ijo.0801229

Screens, memory and hyperpalatability

A meta-analysis across 24 experiments looked at distraction and memory during eating. Distraction raised immediate intake moderately and later intake considerably more. When the memory of what had been eaten was strengthened, later intake fell. Notably: merely intending to eat more consciously showed no clear effect.

Then there is the supply. Of 7,757 foods in a US database, 62 percent met at least one criterion for the combination of fat, sugar and salt that speaks to the reward system particularly strongly.

Sleep: two nights are enough

Clinical The benchmark shifts

Eve Van Cauter's group in Chicago had 12 healthy young men sleep short for two days and long for two days, with calorie intake controlled.

Under sleep restriction leptin fell by 18 percent, ghrelin rose by 28 percent, hunger by 24 percent. Appetite rose most for carbohydrate rich foods, by 33 to 45 percent. The authors name the small sample as a limit themselves.

For you this means: two short nights can be enough to shift your satiety system measurably.

Spiegel K et al. Ann Intern Med. 2004;141(11):846-50. DOI: 10.7326/0003-4819-141-11-200412070-00008 · Taheri S et al. PLoS Med. 2004;1(3):e62. DOI: 10.1371/journal.pmed.0010062

In an observational study with 1,024 people, the same pattern appeared in everyday life. An observation proves no cause, but it fits the laboratory finding.

What makes the signal louderWhat turns it down
Protein in the mealA diluted protein share
Volume, water, viscous fiberHigh energy density
Chewing time, slow paceSoft texture, 69 kcal per minute
Solid formLiquid calories
A visible mealA screen on the side
Enough sleepTwo short nights
Reframe

With all of this you are not turning the transmitter. You are turning the receiver. That is good news, because receivers can be influenced without fighting against yourself.

And now you know why strict diet rules of all things can have a side effect here.

Why strict rules can replace body awareness

The usual advice goes: if you no longer feel your fullness, just count. Calories, grams, points. Then you do not need the feeling. That is logical. And exactly there lies a difficulty that seems important to me.

Counting replaces the inner measurement with an outer one. That can take the pressure off in the short term. But a crutch does not train a muscle. Anyone eating by outside numbers for years may not be practicing how to read their own signals, but rather how to override them.

This is explicitly not a devaluation of nutritional counseling. For many people structure is right, and classical nutritional medicine works with measurable quantities for good reason. What an integrative view can add is the question: what happens to perception along the way?

The data give hints. In the twelve week study, intake fell by 441 kilocalories per day without anyone counting. The meta-analysis on attention showed the reverse: the mere intention to eat more consciously had no clear effect. What counted was the visibility of the meal.

The core in one sentence

A number is a map. Your satiety signal is the terrain. Maps are useful. But whoever only looks at the map unlearns how to feel the ground underfoot.

Clinically I often see two things at once after long phases with strict rules. People know very precisely what a food contains. And very imprecisely how full they currently are. That is an observation, not a study result.

Important note

A disturbed sense of fullness can also be a symptom. If eating constantly causes anxiety, if control and loss of control alternate, if thoughts about food or your body take up a large part of the day, then this is not a topic for nutrition tips. Then professional help is the right path, and early. More on that in Understanding eating disorders: body and mind.

For the same reason you will deliberately find no calorie recommendations and no target weights here. Both belong in a personal conversation.

Reframe

The goal is not to count better. The goal is to feel something again that you already have anyway.

And now you know why the last section names directions and not a plan.

Learning to read your biofeedback: directions instead of rules

You know the logic by now: make the signal louder, turn the interference down. A documented training protocol for the sense of fullness does not exist, and I do not want to invent one. What does exist are directions with usable evidence.

Five directions, no rules

  • Protein first. Not as a diet, but as an order on the plate. Start with the share your body regulates towards, according to the hypothesis.
  • More time at the table. Not counting chews, but giving the message time to arrive.
  • Volume and viscous fiber. Soup, salad, oats, legumes.
  • Chew your calories instead of drinking them. If a drink delivers energy, it often barely gets accounted for.
  • Protect your sleep. Two short nights can shift the hormonal picture measurably. It is the most invisible lever of them all.

On the order of food on the plate, an honest classification. A widely cited pilot study with eleven people with type 2 diabetes compared the same meal with carbohydrates first and with protein and vegetables first. Blood sugar values were clearly lower with protein first. The work suggests that the order can change the metabolic response. It does not show that protein first fills you up, because that was not measured at all. More on this in Avoiding blood sugar spikes.

For self observation I like to use a simple inner scale, from clearly hungry through pleasantly neutral to uncomfortably full. Not in order to judge, but in order to look again. The question is not: did I eat too much? It is: where am I right now?

You are not training your sense of fullness. You are clearing the line so it can arrive again.

Shukri Jarmoukli

What I often see in my consulting room: people who turn only one dial are frequently disappointed. People who change two or three at once, usually protein, pace and sleep, report a difference more often. That is my observation, not a study.

And if you would like this classified for your own situation: below this article you will find the option to book an appointment.

A final reframe

Your body never stopped talking to you. The question was always just whether the line is clear.

And now you know why it pays to think less about willpower and more about signal strength.

Common questions about satiety and protein

Why am I not full even though I ate enough?

Fullness does not come from the amount of calories as such, it comes from signals: stomach stretch, gut hormones like CCK, GLP-1 and PYY, and the message traveling along the vagus nerve. When a meal has little volume, gets eaten fast and contains little protein, these signals turn out weaker. Add the interference: screens, stress and too little sleep. So it may well be that enough energy arrived, but too little message.

Does protein really fill you up more than carbohydrate or fat?

In controlled studies, yes. Protein dampens the hunger hormone ghrelin most strongly across the whole time course, while carbohydrate lowers hunger quickly at first and then lets it rebound above baseline. In a twelve week study, spontaneous energy intake fell by about 441 kilocalories per day when the protein share rose from 15 to 30 percent, without anyone counting. For the meal that follows immediately, though, the effect is less reliable.

How much protein per meal do I need in order to feel full?

There is no universal number, and I deliberately give no recommendation here. A large review names 1.2 to 1.6 grams of protein per kilogram of body weight per day as the range studied, spread across meals of roughly 25 to 30 grams each. Those are study figures, not an instruction for your kitchen. What fits you depends on kidney function, age, activity and pre-existing conditions, and belongs in a medical conversation.

What is the protein leverage hypothesis in one sentence?

It says that your body regulates primarily towards a certain absolute amount of protein and keeps eating until that amount is reached. If protein gets diluted in the food, for example by fatty, starchy convenience products, the total amount you eat rises. The hypothesis comes from the nutritional ecologists Simpson and Raubenheimer. It is well supported, but not symmetrical: more protein lowers intake more reliably than less protein raises it.

Is it true that fullness only arrives after 20 minutes?

The 20 minutes are a rule of thumb, not a measured quantity. Something else is documented and more important: the same meal eaten in 30 instead of 5 minutes produced clearly higher PYY and GLP-1 responses. And across 22 studies, eating more slowly went along with lower energy intake, without people being hungrier afterwards. So the direction holds, the exact number is a simplification.

Which food keeps you full the longest?

In the Satiety Index of 1995, boiled potatoes led the field at 323 percent, measured against white bread at 100 percent. At the bottom sat the croissant at 47 percent, roughly a sevenfold difference at the same calorie count. The values tracked most strongly with water content and portion weight, then with fiber and protein. Fat content and high palatability tracked negatively.

Why do smoothies and juices fill you up less than whole fruit?

Because your body barely accounts for liquid calories. In a crossover study, the same people compensated for extra solid calories by 118 percent, for liquid ones by minus 17 percent. Body weight and BMI rose only in the liquid phase, and reported hunger showed no difference. Add the pace: a glass is drunk in a minute, the same amount of fruit needs many minutes of chewing.

Can I train my sense of fullness again?

There is no documented training program, and that deserves to be said honestly. What has shown something in studies are the conditions around eating: eat more slowly, more volume and viscous fiber, more protein, make the meal visible and memorable, sleep enough. Merely intending to be more mindful showed no clear effect. So it is less about training and more about turning the interference down.

Why am I hungrier after a bad night of sleep?

Two short nights were enough in a controlled study to lower leptin by about 18 percent and raise ghrelin by about 28 percent. Reported hunger rose by 24 percent, appetite for calorie dense, carbohydrate rich foods by 33 to 45 percent. In a cohort of 1,024 people, the same pattern appeared in everyday life. That is not a willpower problem, it is a shifted benchmark.

Why do I eat more in front of a screen without noticing?

In meta-analyses, distraction raises immediate intake moderately and later intake considerably more. Memory appears to play a substantial role: your body seems to count with what you remember. When the memory of the meal was strengthened, later intake fell. When visible information about how much had already been eaten was removed, it rose.

Is a large stomach to blame when I never feel full?

Stomach stretch is indeed a satiety signal, reported through mechanosensors and the vagus nerve. The popular idea of a stretched out stomach that keeps you permanently hungry could not be backed by a solid human study during the research for this article. I therefore treat it as an open question. Something else is documented: volume counts, regardless of how big your stomach is.

Are protein shakes a good answer for more fullness?

They can fill a gap, but they carry a drawback that fits the topic of this article exactly: they are liquid. In studies, liquid calories are accounted for less well and taken up faster. If protein is missing in everyday life, a shake can be a sensible interim solution. An egg, quark, lentils or fish can deliver the same amount of protein with chewing time, volume and water alongside.

Why do ultra-processed foods fill you up less even though they have the same calories?

Two reasons come together. First the dilution: from the lowest to the highest fifth of ultra-processed food intake, the protein share of the diet fell from 18.2 to 13.3 percent. Second the pace: the mean energy intake rate rose from about 35.5 to 69.4 kilocalories per minute. In an inpatient trial, the same people ate 508 kilocalories per day more on the ultra-processed diet, and that extra explicitly did not come from protein.

Satiety in the bigger picture

Satiety hangs together with blood sugar, insulin and silent inflammation. On fat quality, Omega-3 from plants and animals fits well, and on reading nutrition dogma critically, Cholesterol and science.

On the link between silent inflammation and weight, the path leads on to Inflammation and weight.

SJ

Shukri Jarmoukli

Physician, Integrative Medicine · ViveCura Berlin

I work in my private practice at the intersection of classical medicine, functional medicine and Clinical Psychoneuroimmunology. With nutrition questions I am less interested in which diet is currently popular, and more in which signals a body sends and what drowns those signals out in everyday life.

This article does not replace medical advice. It is meant to help you place your own observations better and ask better questions.

ViveCura, Privatpraxis Shukri Jarmoukli, Skalitzer Straße 137, 10999 Berlin

Scientific sources

  1. Simpson SJ, Raubenheimer D. Obesity: the protein leverage hypothesis. Obes Rev. 2005;6(2):133-42. DOI: 10.1111/j.1467-789X.2005.00178.x [Mechanism Review]
  2. Raubenheimer D, Simpson SJ. Protein appetite as an integrator in the obesity system: the protein leverage hypothesis. Philos Trans R Soc Lond B Biol Sci. 2023;378(1888):20220212. DOI: 10.1098/rstb.2022.0212 [Review]
  3. Gosby AK, Conigrave AD, Lau NS et al. Testing protein leverage in lean humans: a randomised controlled experimental study. PLoS ONE. 2011;6(10):e25929. DOI: 10.1371/journal.pone.0025929 [RCT, n=22]
  4. Gosby AK, Conigrave AD, Raubenheimer D, Simpson SJ. Protein leverage and energy intake. Obes Rev. 2014;15(3):183-91. DOI: 10.1111/obr.12131 [Meta-analysis, k=38]
  5. Martens EA, Lemmens SG, Westerterp-Plantenga MS. Protein leverage affects energy intake of high-protein diets in humans. Am J Clin Nutr. 2013;97(1):86-93. DOI: 10.3945/ajcn.112.046540 [RCT, n=79]
  6. Weigle DS, Breen PA, Matthys CC et al. A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. Am J Clin Nutr. 2005;82(1):41-8. DOI: 10.1093/ajcn.82.1.41 [Clinical Trial, n=19]
  7. Martínez Steele E, Raubenheimer D, Simpson SJ, Baraldi LG, Monteiro CA. Ultra-processed foods, protein leverage and energy intake in the USA. Public Health Nutr. 2018;21(1):114-124. DOI: 10.1017/S1368980017001574 [Cohort, n=9,042]
  8. Raubenheimer D, Machovsky-Capuska GE, Gosby AK, Simpson S. Nutritional ecology of obesity: from humans to companion animals. Br J Nutr. 2014;113 Suppl:S26-39. DOI: 10.1017/S0007114514002323 [Review]
  9. Leidy HJ, Clifton PM, Astrup A et al. The role of protein in weight loss and maintenance. Am J Clin Nutr. 2015;101(6):1320S-1329S. DOI: 10.3945/ajcn.114.084038 [Review]
  10. Westerterp-Plantenga MS. Protein intake and energy balance. Regul Pept. 2008;149(1-3):67-9. DOI: 10.1016/j.regpep.2007.08.026 [Mechanism Review]
  11. Cummings DE, Purnell JQ, Frayo RS, Schmidova K, Wisse BE, Weigle DS. A preprandial rise in plasma ghrelin levels suggests a role in meal initiation in humans. Diabetes. 2001;50(8):1714-9. DOI: 10.2337/diabetes.50.8.1714 [Human Study, n=10]
  12. Foster-Schubert KE, Overduin J, Prudom CE et al. Acyl and total ghrelin are suppressed strongly by ingested proteins, weakly by lipids, and biphasically by carbohydrates. J Clin Endocrinol Metab. 2008;93(5):1971-9. DOI: 10.1210/jc.2007-2289 [RCT, n=16]
  13. Batterham RL, Cohen MA, Ellis SM et al. Inhibition of food intake in obese subjects by peptide YY3-36. N Engl J Med. 2003;349(10):941-8. DOI: 10.1056/NEJMoa030204 [RCT, n=24]
  14. Maljaars PWJ, Peters HPF, Mela DJ, Masclee AAM. Ileal brake: a sensible food target for appetite control. A review. Physiol Behav. 2008;95(3):271-81. DOI: 10.1016/j.physbeh.2008.07.018 [Mechanism Review]
  15. Krieger JP. Intestinal glucagon-like peptide-1 effects on food intake: physiological relevance and emerging mechanisms. Peptides. 2020;131:170342. DOI: 10.1016/j.peptides.2020.170342 [Mechanism Review]
  16. Berthoud HR. Vagal and hormonal gut-brain communication: from satiation to satisfaction. Neurogastroenterol Motil. 2008;20 Suppl 1:64-72. DOI: 10.1111/j.1365-2982.2008.01104.x [Mechanism Review]
  17. de Lartigue G. Putative roles of neuropeptides in vagal afferent signaling. Physiol Behav. 2014;136:155-69. DOI: 10.1016/j.physbeh.2014.03.011 [Mechanism Review]
  18. Simpson K, Parker J, Plumer J, Bloom S. CCK, PYY and PP: the control of energy balance. Handb Exp Pharmacol. 2012;(209):209-30. DOI: 10.1007/978-3-642-24716-3_9 [Mechanism Review]
  19. de Graaf C, Blom WAM, Smeets PAM, Stafleu A, Hendriks HFJ. Biomarkers of satiation and satiety. Am J Clin Nutr. 2004;79(6):946-61. DOI: 10.1093/ajcn/79.6.946 [Review]
  20. Holt SH, Miller JC, Petocz P, Farmakalidis E. A satiety index of common foods. Eur J Clin Nutr. 1995;49(9):675-90. PMID: 7498104 [Human Study, 38 foods]
  21. Wanders AJ, van den Borne JJGC, de Graaf C et al. Effects of dietary fibre on subjective appetite, energy intake and body weight: a systematic review of randomized controlled trials. Obes Rev. 2011;12(9):724-39. DOI: 10.1111/j.1467-789X.2011.00895.x [Systematic Review, 58 comparisons]
  22. Flood JE, Rolls BJ. Soup preloads in a variety of forms reduce meal energy intake. Appetite. 2007;49(3):626-34. DOI: 10.1016/j.appet.2007.04.002 [RCT, n=60]
  23. DiMeglio DP, Mattes RD. Liquid versus solid carbohydrate: effects on food intake and body weight. Int J Obes Relat Metab Disord. 2000;24(6):794-800. DOI: 10.1038/sj.ijo.0801229 [Crossover Study, n=15]
  24. Fazzino TL, Rohde K, Sullivan DK. Hyper-palatable foods: development of a quantitative definition and application to the US food system database. Obesity (Silver Spring). 2019;27(11):1761-1768. DOI: 10.1002/oby.22639 [Systematic Review, 7,757 foods]
  25. Hall KD, Ayuketah A, Brychta R et al. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell Metab. 2019;30(1):67-77.e3. DOI: 10.1016/j.cmet.2019.05.008 [RCT, n=20]
  26. Forde CG, Mars M, de Graaf K. Ultra-processing or oral processing? A role for energy density and eating rate in moderating energy intake from processed foods. Curr Dev Nutr. 2020;4(3):nzaa019. DOI: 10.1093/cdn/nzaa019 [Review, 327 foods]
  27. Kokkinos A, le Roux CW, Alexiadou K et al. Eating slowly increases the postprandial response of the anorexigenic gut hormones, peptide YY and glucagon-like peptide-1. J Clin Endocrinol Metab. 2010;95(1):333-7. DOI: 10.1210/jc.2009-1018 [RCT, n=17]
  28. Robinson E, Almiron-Roig E, Rutters F et al. A systematic review and meta-analysis examining the effect of eating rate on energy intake and hunger. Am J Clin Nutr. 2014;100(1):123-51. DOI: 10.3945/ajcn.113.081745 [Meta-analysis, k=22]
  29. Slyper A. Oral processing, satiation and obesity: overview and hypotheses. Diabetes Metab Syndr Obes. 2021;14:3399-3415. DOI: 10.2147/DMSO.S314379 [Review]
  30. Robinson E, Aveyard P, Daley A et al. Eating attentively: a systematic review and meta-analysis of the effect of food intake memory and awareness on eating. Am J Clin Nutr. 2013;97(4):728-42. DOI: 10.3945/ajcn.112.045245 [Meta-analysis, k=24]
  31. Spiegel K, Tasali E, Penev P, Van Cauter E. Brief communication: sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Ann Intern Med. 2004;141(11):846-50. DOI: 10.7326/0003-4819-141-11-200412070-00008 [RCT, n=12]
  32. Taheri S, Lin L, Austin D, Young T, Mignot E. Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index. PLoS Med. 2004;1(3):e62. DOI: 10.1371/journal.pmed.0010062 [Cohort, n=1,024]
  33. Shukla AP, Iliescu RG, Thomas CE, Aronne LJ. Food order has a significant impact on postprandial glucose and insulin levels. Diabetes Care. 2015;38(7):e98-9. DOI: 10.2337/dc15-0429 [RCT, n=11, pilot study]
Transparency about the evidence The statements on protein and energy intake rest on randomized controlled trials and meta-analyses in humans and are comparatively well documented. The protein lever is not symmetrical here: a higher protein share lowers intake more reliably than a lower one raises it, and at least one well conducted study found no evidence for the low step. The statements on the vagus nerve and the brainstem come from mechanism reviews, not from intervention studies in humans. How the brain does the math on these messages exactly is still open. The Satiety Index is a paper from 1995 with small groups and without a registered DOI, only the PMID is listed there. The 20 minute rule is a rule of thumb and not a measured quantity. The idea of a stretched out stomach could not be backed by a solid human study and stays an open question here. The pilot study on meal order covers eleven people with type 2 diabetes and measures blood sugar, not fullness. All core evidence in this article comes from human studies, meta-analyses or mechanism reviews in humans. Animal and cell experiments were deliberately not drawn on. Where I speak of clinical observation, I have named it explicitly in the text and have not presented it as proof.

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