I'm trying to get at the caloric load and macronutrient composition of meal vs the physical volume of food and its impact on satiety.
All other things being equal, if you consume your macronutrients from small, dense foods/liquids vs not, does this influence satiety? For example, if I get 20 grams of fat from pieces of 85% Lindt chocolate vs an equivalent amount of fat from my steak, one clearly is of much greater volume than the other and therefore physically fills my stomach differently. I realize this is apples and oranges comparison but assume that the rest of the meal is such that the macronutrient composition and calories are identical.
If satiety is driven by the hormonal response to foods, is the volume irrelevant?
asked byZZ (93)
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on March 07, 2011
at 01:15 AM
I watched lecture on Youtube recently given by Dr. Bernstein (as in Dr. Bernstein's Diabetes Diet). In this lecture he stated that you could, in theory, swallow a handful of small pebbles and this volume would stretch the gut and signal the brain that you were 'full'. Since we cannot digest rock it gives a physical signal as opposed to a signal coming from digesting food.
on March 06, 2011
at 07:40 PM
Clearly volume, and not just macronutrient content, affects satiety. The stomach contains stretch receptors that signal satiety to the brain via the vagus nerve. A new pacemaker device can trick someone's body into feeling that the stomach's full even though they're just starting to eat. Also, a recent study showed that pureed "stealth veggies" surreptitiously added to food could cut daily energy consumption by 360 calories. If it was just fat and protein that induced satiey, this strategy would not work.
The short answer to your question is no, volume is not irrelevant.
on March 06, 2011
at 07:32 PM
I'm full for a lot longer if I eat a bunch of, say, whipped cream versus an equivalent volume of lamb.
Saturated fat increases leptin levels, but so too does total calories and carb intake: http://jcem.endojournals.org/cgi/content/abstract/83/12/4382
This one is also interesting: http://cat.inist.fr/?aModele=afficheN&cpsidt=927993
If leptin is a satiety hormone, then one will be most sated by a heavy saturated and monunsaturated fat intake and little exercise. Kind of agrees with Taubes' line of thinking. Obviously we should continue to exercise, but it does increase hunger. If you then feed that hunger with considerable amounts of fat, all told you don't get fatter (at least in my experience).
on March 06, 2011
at 06:42 PM
I wish I still had the link but sometime last year I ran across a report of a study in which researchers had pinpointed a chemical that is released by the small intestine to induce satiety. The chemical is released in response to fat intake. That convinced me that all this talk about fiber and protein invoking satiety because they "make you feel full" was so much smoke and mirrors. It also verified my own experience with having less of an appetite on low-carb/high-fat than I did on the reverse.
Plus I need so much less volume of food if I'm getting more nutrients from what I do eat.
I dunno, you could experiment. I would posit that you won't have the fullness-feeling thing if you eat 20g of fat from Lindt that you'd get from 20g of fat in a steak. You might get the satiety trigger though, chemically. So you might find yourself in the weird position of not being hungry anymore but feeling like you should have eaten more because you're not full yet.
Or, you might get the same exact amount of satiety. You never know til you try.
on March 21, 2012
at 03:11 PM
This a follow-up to what Josh posted on Dr. Bernstein talking about the pebbles. The text following the link is from Dr. Bernstein:
Years back, a patient asked me why her blood sugar jumped significantly every afternoon after she went swimming. I asked what she ate before the swim. “Nothing, just a freebie,” she replied. As it turned out, the “freebie” was lettuce. When I asked her how much lettuce she was eating before her swims, she replied, “A head.”
The small amount of digestible carbohydrate in lettuce should not by itself have caused her blood sugar jump, even considering the quantity she ate. The explanation lies in what I call the Chinese Restaurant Effect. Some Chinese restaurant meals contain large amounts of protein or slow-acting, low-carbohydrate foods, such as bean sprouts, bok choy, mushrooms, bamboo shoots, and water chestnuts, that can make you feel full.
During and after meals, the stomach empties a slurry of food mixed with liquid into the small intestine. The liquid passes through the small intestine and is absorbed, mostly in the large intestine. The solids stretch the walls of the small intestine as they slowly pass through. Cells in the upper part of the small intestine release hormones that signal the pancreas to produce insulin when they’re stretched. (The pancreas is the gland responsible for manufacturing, storing, and releasing insulin in the body.) Large meals cause greater stretching of the intestinal cells, which in turn will secrete proportionately larger amounts of these hormones.
A very small amount of insulin released by the pancreas can cause a large drop in blood sugar, and so the pancreas produces the less potent hormone glucagon to fine-tune the potential excess effect of the insulin. Glucagon acts to increase blood sugar.
The problem arises when the insulin-producing cells of your pancreas the pancreatic beta cells make little or no insulin. Glucagon is still produced, but adequate insulin is not available to offset its effect.
The first lesson here is: Don’t stuff yourself. The second lesson is: There’s no such thing as a freebie. Any solid food that you eat (even pebbles) can raise your blood sugar if you’re diabetic. Trivial amounts, however, such as a small stick of celery, will have negligible effects.