September 18, 2025 • 23 mins
Join my first live wellness workshop on October 2 at 6 PM CT, where we’ll tackle the question: Does Health Need to be a Full-time Job? It's free. Sign up here.
Can the type of food you eat influence how much you eat? In this episode, I explore how calorie density, texture, protein content, hydration, and even your perception of food can all affect fullness—and how understanding these levers can help you better manage your weight without feeling deprived.
We start by revisiting the foundational idea that maintaining a healthy weight impacts your risk of heart disease, diabetes, and cancer. While previous episodes discussed eating slowly and using smaller plates, today’s focus is on how the specific foods you choose can directly affect how much you consume.
Drawing from both personal anecdotes—like my wife Gail’s success with a no-flour, no-sugar approach—and recent science, I explore five key factors. First, calorie density plays a powerful role. In a randomized crossover trial, participants ate 813 more calories per day when consuming ultra-processed foods, even though meals had identical calories and macronutrients. Foods engineered to be hyper-palatable often pack in calories without promoting fullness.
Next, we dive into satiety—that subjective feeling of fullness. A Satiety Index study found that boiled potatoes, oatmeal, apples, and beef left participants feeling fuller than white bread or croissants. Why? One reason might be energy density, as demonstrated in another trial where high-fat lunches led participants to eat nearly 500 extra calories.
We also explore food texture. In a study comparing soft vs. hard meals, participants consumed 20% more from softer options. A similar principle applies to fruit vs. fruit juice, where a five-week trial showed that eating a whole apple before a meal reduced calorie intake by 187 calories compared to juice.
Protein also emerges as a standout. In a small study, a protein-based snack delayed hunger by 60 minutes—far more than fat or carbs. And then there’s hydration. Drinking water before meals may curb appetite, supported by a randomized trial and a systematic review showing that two cups of water before each meal led to significant weight loss over 3–12 months.
Finally, we can’t ignore the psychological piece. In the “sham milkshake” study, participants felt fuller—and had altered hunger hormone levels—based solely on what they thought they were consuming. Mind over matter, indeed.
Throughout the episode, I encourage listeners to explore these ideas with an N of 1 trial, as detailed in Episode 27
Try a protein-rich snack before dinner or a glass of water before meals and see how it changes your appetite.
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:01):
Do you struggle to reach your goal weight or find
it really hard to cut back onthe number of calories that you
eat?
It turns out that how much youeat is influenced by what you
eat.
What are the foods that mighthelp you feel fuller?
How might you plan your meals?
Let's see what the evidencetells us.
(00:24):
Hi, I'm Dr Bobby Du Bois andwelcome to Live Long and Well, a
podcast where we will talkabout what you can do to live as
long as possible and with asmuch energy and figure that you
(00:47):
wish.
Together, we will explore whatpractical and evidence-supported
steps you can take.
Come join me on this veryimportant journey and I hope
that you feel empowered alongthe way.
I'm a physician, ironman,triathlete and have published
several hundred scientificstudies.
(01:09):
I'm honored to be your guide.
Welcome my listeners to episode49.
What you eat affects how muchyou eat Now.
In prior episodes we talkedabout being at a good weight and
(01:29):
why being overweight affectsour heart, our risk of diabetes,
risk of cancer.
We discussed a couple of tipshow eating more slowly might
allow the brain to catch up andthe use of smaller plates might
help us from a portion controlstandpoint.
(01:49):
But is there another secretthat might help us.
And the great answer is yes,the specific foods we eat can
affect how much we eat.
Well, why?
Now?
My dear wife, gail, is on a neweating plan where she's cutting
out flour and sugar and eatinglots of vegetables, and she
(02:13):
finds it's really helpful andshe feels more full.
I've also found, and I'vechatted with you before, that if
I eat something with protein, abit of meat, before a meal, say
15-20 minutes before a meal, itreduces my appetite.
So, not surprisingly, I askedis there any evidence for any of
(02:35):
this, or is it all just aplacebo effect, and are there
other foods to consider?
So down the rabbit hole I wentand what did I find?
Well, the good news is there'sevidence in this space, but not
so good news, as most are fromreally small clinical trials.
So I can't say we have thedefinitive answer, but it might
(02:59):
be enough to give it a try,especially if you try it using
our N of 1 approach.
Now, I do believe that what weeat affects how much we eat, and
there are five aspects thatI'll walk through with you that
seem very important.
First, calorie density.
(03:19):
How many calories do you getper bite?
Think of celery versuscheesecake.
That matters in terms of howfull you feel.
Second, the texture of the foodimpacts things.
Think banana versus carrot,think apple versus apple juice.
(03:40):
Third, what the actual food is.
Is it protein, is it fat, is itcarbs?
Fourth, we may have heard thatif you drink water before your
meal, you might feel fuller andwant to eat less.
And there's a fifth one whichis quite interesting is our
appetite.
(04:00):
Our feeling of fullness isaffected by what we think we're
eating, not necessarily whatwe're actually eating, and that
teaser I'll share more with you.
Well, before diving in, after mylast episode, a reader, a
listener, reached out to me andasked well, I listened to your
(04:21):
episode on does health need tobe a full-time job?
And they said you know, itwould be a great workshop if you
walked through with folks howyou decide what aspects of
wellness to focus on, what mightnot be absolutely necessary.
So I listened, I listened to mylisteners all the time and I
(04:43):
said why not?
So join me for my first everlive web event.
It's free, of course, and it'son Thursday, october 2nd at 6 pm
Central Time.
I'll include a link for you tosign up.
If you already get mynewsletter, I'll send you some
information that way, and ifyou're not on my newsletter,
(05:05):
please already get my newsletter.
I'll send you some informationthat way, and if you're not on
my newsletter, please pleasejoin my newsletter.
Just go to my website, dr Bobby, live long and well, and you
can sign up and tell othersabout the workshop and about the
podcast.
Well, back to, what we eataffects how much we eat.
Now this topic has come up manytimes If you're watching the TV
(05:29):
or reading news media or socialmedia, and it comes up when
discussions aroundultra-processed foods, which
people say are designed to makeyou eat too much or just to eat
a lot and buy more.
I will do an episode onultra-processed foods.
I might call it the good, thebad and the ugly, because there
(05:51):
are a lot of points of view toconsider, but today I just want
to mention as a window into thetopic of what you eat and how
much you eat.
So here's an interesting study.
It's small, but it wasrandomized, and they basically
took people and said okay,you're going to eat
ultra-processed food for a week,or you're going to eat
(06:14):
non-ultra-processed food for aweek, and then they would switch
it up.
So maybe you would first startwith ultra-processed, then go to
not ultra-processed or thereverse.
Now, each meal, whether it wasthe ultra-processed week or not,
had the same calories, had thesame macronutrients, meaning
protein and fat and carbs, andwhat they found was that people
(06:39):
eating the ultra-processed foodsate 813 calories more per day,
meaning it appears from theevidence that what you ate
influenced how much you ate.
So ultra-processed foods, youate a whole bunch more.
Now we know, or we've heard,that ultra-processed foods have
(07:02):
been engineered to get you toeat more, buy more, want more.
Well, what aspects of theultra-processed foods might
drive that?
And it turns out it's many ofthe things that we're going to
walk through in just a moment.
All right, let's take a60,000-foot view.
This is something I suspect allof you have a sense of.
(07:26):
Some foods make you feel fulland others don't, and we call
that satiety, and a group ofresearchers developed an index
of satiety, or how full you feel, for each food.
What did they do?
Well, they fed people variousfoods and then they asked them
(07:46):
every 15 minutes after they atethe food for up to two hours,
how full do you feel?
And then, after that, they letthem eat anything they want and
investigated how much theywanted to eat after eating that
initial food correlated withtheir sense of satiety or
(08:07):
fullness, and so they had awhole long list of foods they
tested.
Now to make a scale, they hadto put something in kind of the
middle and they put white breadand they gave it a score of 100.
Meaning, if it's higher than100, then you feel fuller than
if you ate a certain amount ofwhite bread.
If it was less than 100, then,whatever that was, you didn't
(08:30):
feel as full as had you hadwhite bread.
So what was less satiating, lessfullness producing, than white
bread?
Well, remember, white bread is100.
Donuts were 68 and croissantswere 47.
So those in this study wereless satiating, less fullness
(08:53):
producing, than even white bread.
Okay, so let's go to the otherside of the equation.
What made people feel more full?
Boiled potatoes topped the listat 323.
Oatmeal was 209.
Apples whole apple was 197 andbeef was 176.
(09:15):
So it was very clear in thisstudy that certain foods made
you feel fuller and certainfoods made you feel less full.
So of course, the question iswhy?
What is it about the foods thatmight want you to eat more or
eat less?
What are the drivers, and soI'm going to walk through each
(09:37):
one of those now.
First, let's start with energydensity.
So calories per bite or handfulof something you're going to
grab, whether it's blueberriesor maybe it's chips or maybe
it's, you know, something elselike candy.
Again, think celery versuscheesecake.
(09:58):
Clearly one has more density ofcalories than another.
So they did a randomizedcontrol trial here of 69 people.
Now this study and many otherstudies in this kind of appetite
space were typically done inpeople of normal weight.
So this group had a BMI of 23.
It's interesting it wasn't inobese people.
(10:20):
Most.
All these studies were inpeople of normal weight, and
these studies were what arecalled crossover studies.
They're kind of like end-of-onetrials, so you compare for an
individual, one diet versusanother, one approach versus
another.
That's called a crossover trial.
(10:40):
So what they did is they gavethem a certain type of lunch
meal and we're talking aboutenergy density.
So some were high densitylunches, some were low density
lunches, and after they had thebasic part of the meal, they
said to people well, if you wantto eat some more, if you're
still hungry, here's somesandwich pieces.
(11:01):
So just eat as many as you feellike.
So they had a low-fat meal anda high-fat meal and the low-fat
meal.
The way they created it wasthey used low-fat mayo versus
high fat regular mayo.
They used lower fat chickenversus regular chicken, you know
, like a chicken breast versus achicken thigh.
So in comparing the dense mealsversus not, when it came time
(11:28):
to how full people felt and howmany calories they ultimately
wanted because they could eatthose sandwich bites at the end,
the people that had the highenergy density meal they ended
up eating 484 calories morebefore they felt like they were
done.
So that's quite extraordinary.
(11:50):
So think in the future abouthow dense the calories are,
because that may affect how muchyou want to eat.
Okay, secondary texture Doestexture influence how much you
want to eat?
Again, texture Does textureinfluence how much you want to
eat?
Again, small studies as I said,all of these were typically
small studies, but they wererandomized trials.
(12:11):
There were 50 folks, they wereage 24, and they compared a soft
meal versus a hard texture meal.
Now what do we mean by that?
So a soft meal might be mashedpotatoes and steamed vegetables
and steamed salmon and bananayogurt drink and avocado sauce.
(12:32):
So you can get a sense.
Not a lot of chewing to ingestthat food.
And in the hard meal they mighthave multi-grain rice, you know
which is coarser.
They might have a salad that'sfull of celery and carrots and
cucumber, and maybe chickenbreast and an apple for the end
(12:52):
of the meal.
So what did they find?
The soft meal people ate 20%more weight-wise, calorie-wise,
than the people who had thehigher texture meal.
Okay, so texture seems to haveanother piece of this puzzle.
A part of the texture story andyou may have heard about this is
(13:14):
fruit versus fruit juice.
Does one satisfy your hungermore?
Does it affect how manycalories you're going to eat?
So great study.
Love this one Again small, 58adults, normal BMI, and they
basically tested this out overthe course of five weeks.
(13:35):
And the way they did it is theygave you a pre-meal.
So before you had your fullmeal you had either apple,
applesauce, apple juice wherethey added fiber, or apple juice
without fiber.
So you can get a sense of okay,so we've got the full apple at
one extreme, we have just thestrained juice at the other
(13:59):
extreme.
And they asked people kind ofwhich one made you feel fuller.
You're probably not going to besurprised to hear that the
least hunger that people feltafter about 15 minutes was with
the apple.
And they then also foundbecause after you got your
(14:20):
pre-meal of your apple or applejuice or whatever, you then got
to eat your regular meal andthey measured how much you ate.
So after that pre-meal theyfound that people who drank
apple juice, their meal was 860calories, the applesauce group,
their meal, all that, what theywanted to eat was 800 calories.
(14:43):
And the people who had thepre-meal of an apple, the full
apple, ate 700 calories.
So basically, having an appleversus apple juice as your
pre-meal, there was a differenceof 187 calories.
That is a lot.
Interestingly, they playedaround with whether the juice
(15:05):
had fiber in it or not.
It didn't seem to matter,although other studies have
shown that fiber helps us feelfuller.
Now, clearly, when you thinkabout it from a texture
standpoint, to eat an appleversus applesauce or apple juice
, there's a lot more chewinggoing on, it takes longer to eat
those calories and in the end,solid fruit was more satiety or
(15:31):
fullness creating than the juice.
All right, so that's a second.
That's texture.
How about the type of food?
I said at the beginning thatfor me, protein seems to allow
me not to want to eat quite asmuch.
Now, this study was a reallysmall one.
There were 11 young men who didit and what they did is they
(15:53):
gave them an afternoon snack andthey varied the snack whether
it was high fat, high protein,high carb and then they measured
when they wanted dinner.
So, in other words, did theystay full for a short period of
time and wanted dinner an houror two later, or did they feel
quite full and they reallydidn't rush to dinner for even
(16:15):
further off into the future?
So what did they find?
If you had your protein as asnack, your snack was protein.
You delayed your dinnercompared to not having a snack
by 60 minutes.
Now you may say, dr Bobby, well, maybe any snack would do it.
(16:36):
Nope, dr Bobby, well, maybe anysnack would do it.
Nope, a high carb snack.
You pushed off dinner by 34minutes.
High fat by 25 minutes.
So it turns out from this studyand there are some other
studies like this that proteinmight help us to feel fuller.
(16:57):
In my own personal life that'strue, and at least with this
small study it's true as well.
Okay, two more issues.
They're not exactly like thecharacteristic of the food, but
I think you'll get the pointquickly.
So people have often said well,you'll feel fuller if you drink
(17:19):
water before your meal.
So not water during the meal,but water before the meal.
Tiny study 15 subjects, averageage about 26.
And what they found in this onestudy is that when they gave
you water before the meal,people felt fuller and they ate
less.
But that's now one tiny study.
(17:39):
So there was a systematic reviewthat looked at a bunch of
studies and what they looked atwasn't how much they ate so
that's why it's not in the samecategory as the previous study
but whether you achieved weightloss.
Weight loss.
(18:02):
So they had four studies wherethey tested out whether you had
like two glasses of water beforeeach meal and then they
followed this approach over thecourse of three to 12 months.
Again, it was randomizedbetween people who tried the
water approach and those thatdid not.
And those that had the waterprior to the meal lost
significantly more weight,multiple pounds more, than the
(18:24):
ones that didn't have the waterbefore the meal.
So again, this isn't exactlywhat you eat equates to how much
you eat, but it's related,related.
This last study is just a funstudy, but it is on topic and
it's called the sham milkshakestudy and you could put this in
(18:45):
the mind over matter category ormind over food category, and
this basically isn't what youeat determines how much you eat,
but what you think you'reeating influences how much you
eat.
Now, this is great.
So basically they gave 46different people milkshakes on
(19:07):
two different occasions and itwas about a 380 calorie shake.
So it was a nice tasting niceshake.
Was a nice tasting nice shake.
So first they said to people,or some people, this is the
skinny shake, it only has 140calories to it.
Now, in reality it was actuallythe 380 calorie shake.
(19:29):
And others they told this isthe indulgent shake, it has 620
calories.
And guess who felt fuller?
The people who thought theywere getting the indulgent shake
, even though they were gettingthe exact same shake as
everybody else.
And then they switched it off.
(19:51):
So people got to try all ofthese different approaches.
Okay, so that you know,obviously is psychological, you
know you think it's an indulgentshake, so you're really full
afterwards.
But they also measured hungerhormones like ghrelin, and what
they found was the ghrelinlevels, which relate to how
(20:13):
hungry you feel, reflected.
Again, not what you ate,because again everybody drank
the same actual milkshake, butwhat people thought they ate.
So your brain and your stomachand the secretion of ghrelin
relates to what you think you'reeating.
So I think this is fascinating.
(20:34):
Not that you're going to beable to cheat yourself mentally
as to what you're actuallyeating, but I think it relates
to this.
Okay, we're ready to wrap up.
So, as a reminder, October 7th,at 6 pm, central Time, I will
do the workshop on helping youto explore what to do so that
(20:55):
health and wellness does notneed to be a full-time job.
So I'll give you very practicaltips.
We'll walk through how to do itand by the end of it, hopefully
you'll be able to take it tothe next step.
Okay, on today's topic of whatyou eat affects how much you eat
.
The evidence isn't perfect.
I've said it at the beginning,I'm going to say it at the end.
(21:17):
The evidence isn't perfect.
I've said it at the beginning,I'm going to say it at the end.
I do believe there is arelationship and the data
certainly supports it.
It seems like the criticalfactors are the density of the
food, meaning how many caloriesper bite.
The texture, whether it's softor hard, whether it's protein
versus fat versus carbs Proteinseems to help us feel fuller.
(21:40):
And then, of course, this issueabout water before your meal
and then, of course, what youthink you're actually eating.
Now, the evidence isn't perfect.
So, when the evidence isn'tperfect, what is perfect is to
do an N of 1 trial.
Episode number 27 will walk youthrough it.
(22:00):
You might test out having aprotein snack before eating a
normal meal.
You might test out having aglass of water before a meal.
Of course, you need a way tomeasure it.
You need to try it with thisapproach, try it without the
approach and see what happens.
Again, as always, I hope youlive long and well and when you
(22:26):
eat, I hope you find foods thatmake you feel satisfied and full
.
Thanks so much for listening toLive Long and Well with Dr
Bobby.
If you liked this episode,please provide a review on Apple
or Spotify or wherever youlisten.
If you want to continue thisjourney or want to receive my
(22:50):
newsletter on practical andscientific ways to improve your
health and longevity, pleasevisit me at
drbobbilivelongandwellcom.
That's Dr, as in D-R, bobby,livelongandwellcom.
Do you struggle to reach your goal weight or find
it really hard to cut back onthe number of calories that you
eat?
It turns out that how much youeat is influenced by what you
eat.
What are the foods that mighthelp you feel fuller?
How might you plan your meals?
Let's see what the evidencetells us.
(00:24):
Hi, I'm Dr Bobby Du Bois andwelcome to Live Long and Well, a
podcast where we will talkabout what you can do to live as
long as possible and with asmuch energy and figure that you
(00:47):
wish.
Together, we will explore whatpractical and evidence-supported
steps you can take.
Come join me on this veryimportant journey and I hope
that you feel empowered alongthe way.
I'm a physician, ironman,triathlete and have published
several hundred scientificstudies.
(01:09):
I'm honored to be your guide.
Welcome my listeners to episode49.
What you eat affects how muchyou eat Now.
In prior episodes we talkedabout being at a good weight and
(01:29):
why being overweight affectsour heart, our risk of diabetes,
risk of cancer.
We discussed a couple of tipshow eating more slowly might
allow the brain to catch up andthe use of smaller plates might
help us from a portion controlstandpoint.
(01:49):
But is there another secretthat might help us.
And the great answer is yes,the specific foods we eat can
affect how much we eat.
Well, why?
Now?
My dear wife, gail, is on a neweating plan where she's cutting
out flour and sugar and eatinglots of vegetables, and she
(02:13):
finds it's really helpful andshe feels more full.
I've also found, and I'vechatted with you before, that if
I eat something with protein, abit of meat, before a meal, say
15-20 minutes before a meal, itreduces my appetite.
So, not surprisingly, I askedis there any evidence for any of
(02:35):
this, or is it all just aplacebo effect, and are there
other foods to consider?
So down the rabbit hole I wentand what did I find?
Well, the good news is there'sevidence in this space, but not
so good news, as most are fromreally small clinical trials.
So I can't say we have thedefinitive answer, but it might
(02:59):
be enough to give it a try,especially if you try it using
our N of 1 approach.
Now, I do believe that what weeat affects how much we eat, and
there are five aspects thatI'll walk through with you that
seem very important.
First, calorie density.
(03:19):
How many calories do you getper bite?
Think of celery versuscheesecake.
That matters in terms of howfull you feel.
Second, the texture of the foodimpacts things.
Think banana versus carrot,think apple versus apple juice.
(03:40):
Third, what the actual food is.
Is it protein, is it fat, is itcarbs?
Fourth, we may have heard thatif you drink water before your
meal, you might feel fuller andwant to eat less.
And there's a fifth one whichis quite interesting is our
appetite.
(04:00):
Our feeling of fullness isaffected by what we think we're
eating, not necessarily whatwe're actually eating, and that
teaser I'll share more with you.
Well, before diving in, after mylast episode, a reader, a
listener, reached out to me andasked well, I listened to your
(04:21):
episode on does health need tobe a full-time job?
And they said you know, itwould be a great workshop if you
walked through with folks howyou decide what aspects of
wellness to focus on, what mightnot be absolutely necessary.
So I listened, I listened to mylisteners all the time and I
(04:43):
said why not?
So join me for my first everlive web event.
It's free, of course, and it'son Thursday, october 2nd at 6 pm
Central Time.
I'll include a link for you tosign up.
If you already get mynewsletter, I'll send you some
information that way, and ifyou're not on my newsletter,
(05:05):
please already get my newsletter.
I'll send you some informationthat way, and if you're not on
my newsletter, please pleasejoin my newsletter.
Just go to my website, dr Bobby, live long and well, and you
can sign up and tell othersabout the workshop and about the
podcast.
Well, back to, what we eataffects how much we eat.
Now this topic has come up manytimes If you're watching the TV
(05:29):
or reading news media or socialmedia, and it comes up when
discussions aroundultra-processed foods, which
people say are designed to makeyou eat too much or just to eat
a lot and buy more.
I will do an episode onultra-processed foods.
I might call it the good, thebad and the ugly, because there
(05:51):
are a lot of points of view toconsider, but today I just want
to mention as a window into thetopic of what you eat and how
much you eat.
So here's an interesting study.
It's small, but it wasrandomized, and they basically
took people and said okay,you're going to eat
ultra-processed food for a week,or you're going to eat
(06:14):
non-ultra-processed food for aweek, and then they would switch
it up.
So maybe you would first startwith ultra-processed, then go to
not ultra-processed or thereverse.
Now, each meal, whether it wasthe ultra-processed week or not,
had the same calories, had thesame macronutrients, meaning
protein and fat and carbs, andwhat they found was that people
(06:39):
eating the ultra-processed foodsate 813 calories more per day,
meaning it appears from theevidence that what you ate
influenced how much you ate.
So ultra-processed foods, youate a whole bunch more.
Now we know, or we've heard,that ultra-processed foods have
(07:02):
been engineered to get you toeat more, buy more, want more.
Well, what aspects of theultra-processed foods might
drive that?
And it turns out it's many ofthe things that we're going to
walk through in just a moment.
All right, let's take a60,000-foot view.
This is something I suspect allof you have a sense of.
(07:26):
Some foods make you feel fulland others don't, and we call
that satiety, and a group ofresearchers developed an index
of satiety, or how full you feel, for each food.
What did they do?
Well, they fed people variousfoods and then they asked them
(07:46):
every 15 minutes after they atethe food for up to two hours,
how full do you feel?
And then, after that, they letthem eat anything they want and
investigated how much theywanted to eat after eating that
initial food correlated withtheir sense of satiety or
(08:07):
fullness, and so they had awhole long list of foods they
tested.
Now to make a scale, they hadto put something in kind of the
middle and they put white breadand they gave it a score of 100.
Meaning, if it's higher than100, then you feel fuller than
if you ate a certain amount ofwhite bread.
If it was less than 100, then,whatever that was, you didn't
(08:30):
feel as full as had you hadwhite bread.
So what was less satiating, lessfullness producing, than white
bread?
Well, remember, white bread is100.
Donuts were 68 and croissantswere 47.
So those in this study wereless satiating, less fullness
(08:53):
producing, than even white bread.
Okay, so let's go to the otherside of the equation.
What made people feel more full?
Boiled potatoes topped the listat 323.
Oatmeal was 209.
Apples whole apple was 197 andbeef was 176.
(09:15):
So it was very clear in thisstudy that certain foods made
you feel fuller and certainfoods made you feel less full.
So of course, the question iswhy?
What is it about the foods thatmight want you to eat more or
eat less?
What are the drivers, and soI'm going to walk through each
(09:37):
one of those now.
First, let's start with energydensity.
So calories per bite or handfulof something you're going to
grab, whether it's blueberriesor maybe it's chips or maybe
it's, you know, something elselike candy.
Again, think celery versuscheesecake.
(09:58):
Clearly one has more density ofcalories than another.
So they did a randomizedcontrol trial here of 69 people.
Now this study and many otherstudies in this kind of appetite
space were typically done inpeople of normal weight.
So this group had a BMI of 23.
It's interesting it wasn't inobese people.
(10:20):
Most.
All these studies were inpeople of normal weight, and
these studies were what arecalled crossover studies.
They're kind of like end-of-onetrials, so you compare for an
individual, one diet versusanother, one approach versus
another.
That's called a crossover trial.
(10:40):
So what they did is they gavethem a certain type of lunch
meal and we're talking aboutenergy density.
So some were high densitylunches, some were low density
lunches, and after they had thebasic part of the meal, they
said to people well, if you wantto eat some more, if you're
still hungry, here's somesandwich pieces.
(11:01):
So just eat as many as you feellike.
So they had a low-fat meal anda high-fat meal and the low-fat
meal.
The way they created it wasthey used low-fat mayo versus
high fat regular mayo.
They used lower fat chickenversus regular chicken, you know
, like a chicken breast versus achicken thigh.
So in comparing the dense mealsversus not, when it came time
(11:28):
to how full people felt and howmany calories they ultimately
wanted because they could eatthose sandwich bites at the end,
the people that had the highenergy density meal they ended
up eating 484 calories morebefore they felt like they were
done.
So that's quite extraordinary.
(11:50):
So think in the future abouthow dense the calories are,
because that may affect how muchyou want to eat.
Okay, secondary texture Doestexture influence how much you
want to eat?
Again, texture Does textureinfluence how much you want to
eat?
Again, small studies as I said,all of these were typically
small studies, but they wererandomized trials.
(12:11):
There were 50 folks, they wereage 24, and they compared a soft
meal versus a hard texture meal.
Now what do we mean by that?
So a soft meal might be mashedpotatoes and steamed vegetables
and steamed salmon and bananayogurt drink and avocado sauce.
(12:32):
So you can get a sense.
Not a lot of chewing to ingestthat food.
And in the hard meal they mighthave multi-grain rice, you know
which is coarser.
They might have a salad that'sfull of celery and carrots and
cucumber, and maybe chickenbreast and an apple for the end
(12:52):
of the meal.
So what did they find?
The soft meal people ate 20%more weight-wise, calorie-wise,
than the people who had thehigher texture meal.
Okay, so texture seems to haveanother piece of this puzzle.
A part of the texture story andyou may have heard about this is
(13:14):
fruit versus fruit juice.
Does one satisfy your hungermore?
Does it affect how manycalories you're going to eat?
So great study.
Love this one Again small, 58adults, normal BMI, and they
basically tested this out overthe course of five weeks.
(13:35):
And the way they did it is theygave you a pre-meal.
So before you had your fullmeal you had either apple,
applesauce, apple juice wherethey added fiber, or apple juice
without fiber.
So you can get a sense of okay,so we've got the full apple at
one extreme, we have just thestrained juice at the other
(13:59):
extreme.
And they asked people kind ofwhich one made you feel fuller.
You're probably not going to besurprised to hear that the
least hunger that people feltafter about 15 minutes was with
the apple.
And they then also foundbecause after you got your
(14:20):
pre-meal of your apple or applejuice or whatever, you then got
to eat your regular meal andthey measured how much you ate.
So after that pre-meal theyfound that people who drank
apple juice, their meal was 860calories, the applesauce group,
their meal, all that, what theywanted to eat was 800 calories.
(14:43):
And the people who had thepre-meal of an apple, the full
apple, ate 700 calories.
So basically, having an appleversus apple juice as your
pre-meal, there was a differenceof 187 calories.
That is a lot.
Interestingly, they playedaround with whether the juice
(15:05):
had fiber in it or not.
It didn't seem to matter,although other studies have
shown that fiber helps us feelfuller.
Now, clearly, when you thinkabout it from a texture
standpoint, to eat an appleversus applesauce or apple juice
, there's a lot more chewinggoing on, it takes longer to eat
those calories and in the end,solid fruit was more satiety or
(15:31):
fullness creating than the juice.
All right, so that's a second.
That's texture.
How about the type of food?
I said at the beginning thatfor me, protein seems to allow
me not to want to eat quite asmuch.
Now, this study was a reallysmall one.
There were 11 young men who didit and what they did is they
(15:53):
gave them an afternoon snack andthey varied the snack whether
it was high fat, high protein,high carb and then they measured
when they wanted dinner.
So, in other words, did theystay full for a short period of
time and wanted dinner an houror two later, or did they feel
quite full and they reallydidn't rush to dinner for even
(16:15):
further off into the future?
So what did they find?
If you had your protein as asnack, your snack was protein.
You delayed your dinnercompared to not having a snack
by 60 minutes.
Now you may say, dr Bobby, well, maybe any snack would do it.
(16:36):
Nope, dr Bobby, well, maybe anysnack would do it.
Nope, a high carb snack.
You pushed off dinner by 34minutes.
High fat by 25 minutes.
So it turns out from this studyand there are some other
studies like this that proteinmight help us to feel fuller.
(16:57):
In my own personal life that'strue, and at least with this
small study it's true as well.
Okay, two more issues.
They're not exactly like thecharacteristic of the food, but
I think you'll get the pointquickly.
So people have often said well,you'll feel fuller if you drink
(17:19):
water before your meal.
So not water during the meal,but water before the meal.
Tiny study 15 subjects, averageage about 26.
And what they found in this onestudy is that when they gave
you water before the meal,people felt fuller and they ate
less.
But that's now one tiny study.
(17:39):
So there was a systematic reviewthat looked at a bunch of
studies and what they looked atwasn't how much they ate so
that's why it's not in the samecategory as the previous study
but whether you achieved weightloss.
Weight loss.
(18:02):
So they had four studies wherethey tested out whether you had
like two glasses of water beforeeach meal and then they
followed this approach over thecourse of three to 12 months.
Again, it was randomizedbetween people who tried the
water approach and those thatdid not.
And those that had the waterprior to the meal lost
significantly more weight,multiple pounds more, than the
(18:24):
ones that didn't have the waterbefore the meal.
So again, this isn't exactlywhat you eat equates to how much
you eat, but it's related,related.
This last study is just a funstudy, but it is on topic and
it's called the sham milkshakestudy and you could put this in
(18:45):
the mind over matter category ormind over food category, and
this basically isn't what youeat determines how much you eat,
but what you think you'reeating influences how much you
eat.
Now, this is great.
So basically they gave 46different people milkshakes on
(19:07):
two different occasions and itwas about a 380 calorie shake.
So it was a nice tasting niceshake.
Was a nice tasting nice shake.
So first they said to people,or some people, this is the
skinny shake, it only has 140calories to it.
Now, in reality it was actuallythe 380 calorie shake.
(19:29):
And others they told this isthe indulgent shake, it has 620
calories.
And guess who felt fuller?
The people who thought theywere getting the indulgent shake
, even though they were gettingthe exact same shake as
everybody else.
And then they switched it off.
(19:51):
So people got to try all ofthese different approaches.
Okay, so that you know,obviously is psychological, you
know you think it's an indulgentshake, so you're really full
afterwards.
But they also measured hungerhormones like ghrelin, and what
they found was the ghrelinlevels, which relate to how
(20:13):
hungry you feel, reflected.
Again, not what you ate,because again everybody drank
the same actual milkshake, butwhat people thought they ate.
So your brain and your stomachand the secretion of ghrelin
relates to what you think you'reeating.
So I think this is fascinating.
(20:34):
Not that you're going to beable to cheat yourself mentally
as to what you're actuallyeating, but I think it relates
to this.
Okay, we're ready to wrap up.
So, as a reminder, October 7th,at 6 pm, central Time, I will
do the workshop on helping youto explore what to do so that
(20:55):
health and wellness does notneed to be a full-time job.
So I'll give you very practicaltips.
We'll walk through how to do itand by the end of it, hopefully
you'll be able to take it tothe next step.
Okay, on today's topic of whatyou eat affects how much you eat
.
The evidence isn't perfect.
I've said it at the beginning,I'm going to say it at the end.
(21:17):
The evidence isn't perfect.
I've said it at the beginning,I'm going to say it at the end.
I do believe there is arelationship and the data
certainly supports it.
It seems like the criticalfactors are the density of the
food, meaning how many caloriesper bite.
The texture, whether it's softor hard, whether it's protein
versus fat versus carbs Proteinseems to help us feel fuller.
(21:40):
And then, of course, this issueabout water before your meal
and then, of course, what youthink you're actually eating.
Now, the evidence isn't perfect.
So, when the evidence isn'tperfect, what is perfect is to
do an N of 1 trial.
Episode number 27 will walk youthrough it.
(22:00):
You might test out having aprotein snack before eating a
normal meal.
You might test out having aglass of water before a meal.
Of course, you need a way tomeasure it.
You need to try it with thisapproach, try it without the
approach and see what happens.
Again, as always, I hope youlive long and well and when you
(22:26):
eat, I hope you find foods thatmake you feel satisfied and full
.
Thanks so much for listening toLive Long and Well with Dr
Bobby.
If you liked this episode,please provide a review on Apple
or Spotify or wherever youlisten.
If you want to continue thisjourney or want to receive my
(22:50):
newsletter on practical andscientific ways to improve your
health and longevity, pleasevisit me at
drbobbilivelongandwellcom.
That's Dr, as in D-R, bobby,livelongandwellcom.
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