Why do carbs keep me full and satiated as opposed to proteins and fats?

For me fiber is the most filling by far and since fiber is usually associated with carbs low-carb never made sense for me personally either.

Here is a link to a study about a "fullness factor" that shows that potatoes and whole grain things are among the most filling. http://nutritiondata.self.com/topics/fullness-factor

goldthistime wrote: »

Gotta say, I don't get it. Not only have I seen studies showing that proteins especially are significantly more satiating than carbs, I've seen evidence that fats are more satiating. I think digestion times factor in. Carbs, especially sugary carbs are digested so much faster than fats or proteins.

I wonder if part of our differences in perception have to do with satisfying versus satiating. I wake up quite hungry (I have a tendency to eat my calories earlier in the day). If I didn't have carbs with my breakfast, I wouldn't feel satisfied. If I only had carbs I'd feel wonderfully satisfied but for a shorter period of time.

Now that I think of it though, it might make sense if you produced less GLP-1 than normal. The studies I saw said that ghrelin levels were the same for all three macros, and of the hunger hormones, ghrelin was the most strongly associated with hunger. GLP-1 levels, in addition to perceptions, were what were measured to show that proteins and fats are more satiating than carbs.

The thing for me is if a meal is "satisfying", I'm not going to go looking for more food. Carbs (and carb-combos) give me that "satisfaction" feeling. I can eat a 2 egg omelette with Swiss cheese and bacon and "need" something. When I put that omelette in a tortilla, I'm not "needing" anything. Yeah, it's probably mental that I "need" carbs and am not "satisfied" with the protein + fat.

I assume that the cheese and bacon and eggs aren't going to raise your blood glucose levels much so you would need that tortilla to feel satisfied. Not just mental.

http://press.endocrine.org/doi/abs/10.1210/jc.2012-3835

goldthistime wrote: »

http://press.endocrine.org/doi/abs/10.1210/jc.2012-3835

But http://www.ncbi.nlm.nih.gov/pubmed/17824197 (I've seen others that go the same way, too. This is one reason I find it so annoying that "fat is more satiating" is asserted so often on this forum as if it were a fact. It's not true for me and apparently not for many.)

The Susannah Holt stuff that rankinsect referred to above suggests that focusing just on macros (other than maybe protein) is probably too simplistic, though, and of course there are individual differences. No study is going to be able to tell someone what foods they find most satiating or satisfying -- those are questions the person must answer.

Well certainly any data points not fitting the null hypothesis that fat is satiating would need to be discarded.

Fibre (which apples have lots of), affects the discussion of satiety in fats vs carbs greatly. I'm curious as to whether the study I posted (suggesting fats give greater satiety than carbs) had only low fibre carbs. I can't check into this right now but if someone else did I'd be grateful, otherwise I'll try to have a look later in the week.

You can't pull out one study and think it determines definitively what macros or foods are most satiety-providing, obviously. Studies are all over the place and the one thing that seems clear is that that on average protein helps with satiety. That said, the study cited to support a claim that fat leads to more satiety doesn't actually seem to conclude that at all, but to say there's no difference.

(Also -- again -- that something is true on average (which a study might mention) doesn't mean it is for individuals, so I don't know why someone would ever pull out a single study and claim that it means that someone's personal experience isn't valid for them or can't relate to actual satiety. If that's not what's being attempted here, I am misunderstanding and apologize.)

So back to the cited study, which is kind of interesting, although IMO limited when it comes to the actual reasons people perceive hunger or want to eat (which again I think is largely environmental), as well as possible differences between specific foods within the macro categories.

On the study:

The only participants with a BMI of around 30 were used, 5 men and 11 women. They don't seem to have looked at IR.

The study explains: "Research on the nutritional aspects of appetite control has focused considerable attention on the effects of fat and carbohydrate (26). Fat is often regarded as having a much weaker action on satiety than carbohydrate (27)."

Note: this acknowledges the many findings that suggest it does, something these researchers want to test, among other things, specifically: "to clarify the action of ghrelin, GLP-1, and PYY in the immediate postmeal period, by comparing their natural physiological profiles after the delivery of isoenergetic nutrient meals containing comparable amounts of protein but varying in fat and carbohydrate content."

The meals used were quite extreme for the low fat one: high fat was over 50% fat (38% carb), but low fat was less than 4% fat (and 84% carb). They were measured in some way to determine that they were equally pleasant. Protein was the same, as were calories (590) and volume. They consisted of yogurt, fruit, honey, plus coffee or tea, so not too much fiber, but some -- I'd assume relatively low fiber to keep volume steady, or else I can't see how it works. (Worth noting that people who eat extreme high carb low fat diets -- quite unusual -- in real life typically end up eating a ton of fiber.)

The high-fat, low-carb breakfast caused less increase in insulin and glucose levels -- no surprise there.

There was no difference in the effect on ghrelin, but ghrelin did end up being correlated with hunger.

The higher fat meal caused a greater increase in PYY and GLP-1 levels, which was believed by the researchers to correlate with satiety, but the study seemed to suggest that they were not, particularly.

Specifically, the study concluded:

There was no effect of macronutrient condition on changes in hunger levels throughout the morning.

There was no difference in ad libitum energy intake at the standard lunch meal after either the high-fat/low-carbohydrate or high-carbohydrate/low-fat breakfasts. (There were further studies of different meal sizes.)

From the study: "The 2 semisolid meals differed markedly in fat and carbohydrate content but were of equal energy value, weight, and protein content and of similar perceived palatability. Glucose and insulin profiles clearly demonstrated different metabolic responses to the meals and reflected the different macronutrient composition. The high-carbohydrate (and therefore low-fat) breakfast resulted in a greater response in both glucose and insulin. The meals did not differ in their effects on the postprandial profiles of hunger or fullness or in the amount of food consumed at the test meal. These meals therefore had similar actions on the phases of satiety and on satiation (meal size)."

lemurcat12 wrote: »

You can't pull out one study and think it determines definitively what macros or foods are most satiety-providing, obviously. Studies are all over the place and the one thing that seems clear is that that on average protein helps with satiety. That said, the study cited to support a claim that fat leads to more satiety doesn't actually seem to conclude that at all, but to say there's no difference.

(Also -- again -- that something is true on average (which a study might mention) doesn't mean it is for individuals, so I don't know why someone would ever pull out a single study and claim that it means that someone's personal experience isn't valid for them or can't relate to actual satiety. If that's not what's being attempted here, I am misunderstanding and apologize.)

So back to the cited study, which is kind of interesting, although IMO limited when it comes to the actual reasons people perceive hunger or want to eat (which again I think is largely environmental), as well as possible differences between specific foods within the macro categories.

On the study:

The only participants with a BMI of around 30 were used, 5 men and 11 women. They don't seem to have looked at IR.

The study explains: "Research on the nutritional aspects of appetite control has focused considerable attention on the effects of fat and carbohydrate (26). Fat is often regarded as having a much weaker action on satiety than carbohydrate (27)."

Note: this acknowledges the many findings that suggest it does, something these researchers want to test, among other things, specifically: "to clarify the action of ghrelin, GLP-1, and PYY in the immediate postmeal period, by comparing their natural physiological profiles after the delivery of isoenergetic nutrient meals containing comparable amounts of protein but varying in fat and carbohydrate content."

The meals used were quite extreme for the low fat one: high fat was over 50% fat (38% carb), but low fat was less than 4% fat (and 84% carb). They were measured in some way to determine that they were equally pleasant. Protein was the same, as were calories (590) and volume. They consisted of yogurt, fruit, honey, plus coffee or tea, so not too much fiber, but some -- I'd assume relatively low fiber to keep volume steady, or else I can't see how it works. (Worth noting that people who eat extreme high carb low fat diets -- quite unusual -- in real life typically end up eating a ton of fiber.)

The high-fat, low-carb breakfast caused less increase in insulin and glucose levels -- no surprise there.

There was no difference in the effect on ghrelin, but ghrelin did end up being correlated with hunger.

The higher fat meal caused a greater increase in PYY and GLP-1 levels, which was believed by the researchers to correlate with satiety, but the study seemed to suggest that they were not, particularly.

Specifically, the study concluded:

There was no effect of macronutrient condition on changes in hunger levels throughout the morning.

There was no difference in ad libitum energy intake at the standard lunch meal after either the high-fat/low-carbohydrate or high-carbohydrate/low-fat breakfasts. (There were further studies of different meal sizes.)

From the study: "The 2 semisolid meals differed markedly in fat and carbohydrate content but were of equal energy value, weight, and protein content and of similar perceived palatability. Glucose and insulin profiles clearly demonstrated different metabolic responses to the meals and reflected the different macronutrient composition. The high-carbohydrate (and therefore low-fat) breakfast resulted in a greater response in both glucose and insulin. The meals did not differ in their effects on the postprandial profiles of hunger or fullness or in the amount of food consumed at the test meal. These meals therefore had similar actions on the phases of satiety and on satiation (meal size)."

Just want to pop in to say thank you for taking the time to review the study. I still hold the opinion that fat will keep me feeling full for longer than a carb (although I probably now need to qualify that as a carb that is devoid of fibre), and I did hold up this study to support my view. I'm hoping that holding up one study to support a viewpoint isn't considered offensive, because this stuff is time consuming. Further to that, the abstracted version gave information that led me to a different conclusion, than the authors came to in the detailed version apparently. I just want to point out that I didn't purposely misrepresent anything. You made several points that I'd like to discuss further but timewise I just can't atm. Anyway, thanks again for taking the time to look at the study in detail.

In with the...carbs keep me more full crowd...