Why measure carbs and protein per Day?

#1

I’ve been thinking, we all look at the 20 grams per day of carbs, or the formula for grams of protein per day, and eat these on a per day basis. But why? What is really going on and should we be thinking per day, or should we be thinking in terms of smaller periods like some number of hours? For that matter, why not think in per week (I think the answer is clearer on that one, but just throwing it out)?

Is the per day meant to be ‘within any given 24 hour time frame’? So, if I eat 10 carbs at 4pm on Day 1, I cannot eat more than 10 carbs more between that time and 4pm on day 2? Or is it (what seems less likely) that I can eat 15 carbs at 10pm on day 1 and 10 more carbs at 7 am on day 2? (Putting aside the discussion about whether you can individually handle more or less than 20 g per day).

This can likewise translate to protein.

My understanding is it takes a certain amount of time for the body to process (however it will) carbs and protein. With carbs being retained for at most 16 hours or so (I could be wrong on that number, someone correct it please, but the exact number isn’t necessarily important here) and protein taking about 5 hours to fully digest usually. Where the insulin stays is another question, of course, and probably someone has the answer to that one.

But so, is the 20 gram per day idea a safe limit so that if you ate 20 grams late at night and the next day ate 20 grams early in the morning you will still be in a safe ketosis range with regards to insulin (on average)? Is the 20 grams really what the body can handle intake of in one shot, and then can’t handle for another 24 hours, or another 16 hours? Is it assumed the grams are spread out over the day, so that eating 20 grams at one time actually kicks people out of ketosis due to the insulin it creates, whereas if it were spread out over some hours it wouldn’t (in which case, shouldn’t we talk about grams per hour)?

(G. Andrew Duthie) #2

With no disrespect intended, I think you’re overthinking this.

The guidelines of keeping carbs under 20 grams a day is something that will ensure that almost anyone will end up in ketosis if they follow it. Many can stay in ketosis at higher levels, but < 20g makes it a surer thing.

If you want to think of it as 20g from sleep to sleep, that should work out fine.

In terms of the actual metabolic effect, of course it’s more complicated. Eating 20 grams of sugar in a sitting will have a larger effect on insulin than eating 20 grams of carbs worth of broccoli. And there’s some evidence that fat content of a meal can help blunt the impact as well, to a point.

But particularly for those just getting started, keeping it simple is more important, hence the 20g recommendation.

Make sense?

(Kathy L) #3

Yes, that’s way too much thinking for me… I figure midnight to midnight-& don’t worry about it,

#4

I figured 20 grams was probably a “safe zone” regulation so that this wouldn’t matter, but I’d both rather not assume that with nothing to base it on, and would rather understand what is really going on, regardless if a 20 grams per day idea, however you play it out, is sufficient.

Part of that is because over the last couple years of doing keto and otherwise looking into nutrition and health myself, I’ve found more and more that there are important nuances that often get skipped or missed that can make a big difference for, well, anything (weight loss, wellness, mood, whatever), and partially because the topic interests me and I simply like knowing what is really going on.

I’m not asking because I think it’s absolutely necessary to know in order to follow a ketogenic diet (I’ve done it for years without knowing), I’m asking because I’m curious about these details, and you never know what light understanding nuances can shed on other matters or questions that might come up.

#5

I would say, to keep it simple, under 20g of carbs in your normal feeding window.

Of course, the smaller the feeding window is each day, the more time your body has to be in low insulin (fasting) state, the better.

#6

Sure, but not everyone doing even a nutritional ketogenic diet uses fasting/feeding windows and the 20 grams doesn’t come from that context. That still doesn’t explain what’s going on and whether it would be more appropriate to think in, say, 5 grams per 6 hours or 20 grams per 16 hours, or 30 grams per 24 hours ensuring at no time there isn’t a 12 hour period where a total of 20 grams has been consumed (end of one day, start of next).

I’m actually not trying to keep it simple here, I want the details.

(eat more) #7

hi i’m new to this community but i figure i’ll just jump right in :slight_smile: hi everyone! :ghost:

it’s been a lot of years since i absorbed this information so hopefully i don’t ramble getting it from the recesses of my brain lol

everyone has a feeding window whether it’s planned, fasted, or they call it that.unless you sleep eat :wink:

when you consume any macronutrient it’s converted for immediate use…what can’t be used immediately is converted to glycogen and stored in your liver for later use…once the liver is full it activates insulin which shuttles any remaining resources to fat cells.
so if you have a surplus of any macronutrient and your liver is already full it’s like overfilling your car’s gas tank and letting the excess spill all over the ground…only in this case the ground is your fat cells.
carbs are converted to glucose and glycogen with the least effort so they’re first.
with higher carb eating most ppl continue to over fill their “gas tank”…glycogen stores are still high from last meal of the day and then they wake up and refill/overfill.

so really the goal is to deplete and never overfill glycogen stores…glycogen is depleted from life, sleep (cell regeneration), exercise…so technically some ppl can achieve this without a carb limit. having a daily carb limit just makes more sense to me.
a 20g daily limit is the “standard” to guarantee depleted glycogen…i personally wouldn’t recommend all 20g at last meal and then 20g first meal next day…i think breaking it down into hours is unnecessary

i don’t know if this answered your question but there’s some deets…i hope it helped
EDIT: i’m an over thinker

#8

I expect most people sleep 6-9 hours… that would be your fasting window.

(betsy.rome) #9

Back when I became an insulin-dependent maternal diabetic (now a T2D in remission), my OB told me, divide your food up into 5 small meals per day. The idea was to keep BS from going too low or too high at any one time, to not expose the baby to wide swings in BS, with a goal of reducing the risk of birth defects and preventing an oversize baby.

It’s the opposite idea from a 16:8 fasting:eating window. Keto keeps BS in a lower constant range. But if someone experiences wide swings in BS on keto, it might help to alternate fasting with the small / frequent meal approach. The 16:8 or smaller window could send BS higher if you’re getting all your food energy in one short timeframe.

#10

That at least comes closer to answering the question and explains some things. Still, I understand it may not be necessary to break down into hours, but if the mechanisms really are working at an hourly rate (or smaller, or whatever) why not? Is there something special about a day, or is it simply a convenience?

#11

Most people, sure, but ever heard of the uberman sleep schedule? (There are also plenty of people that simply sleep less, or more, or at non regular intervals).

(eat more) #12

i think part convenience but unless you live your life exactly the same way everyday you’d be adjusting daily/hourly…which is cool if manageable. i’m sure there are some nutrient timing and keto articles out there that might be more definitive
for me personally the daily limit is my choice because i don’t want the pressure of “omg i ate zucchini before i was supposed to” i’m an anti-rule rule follower :joy:

(carl) #13

The ideal day for me is one meal between noon and 3PM, and nothing else for 23 hours except for water and coffee. Life gets in the way, of course, so I embrace social situations and unavoidable meals, but I always strive for that pattern. It simply works best for me. In that one meal I eat 70 is grams of protein (sometimes more), carbs only from salad veggies, and as much fat as I want. I eat until I’m full and stop. Protein is usually a fatty cut of meat with a sauce comprised of drippings, butter and/or cream, and flavorings (herbs, garlic, onion powder, etc.). After eating I might have some seltzer with apple cider vinegar and a square or two of dark chocolate.

#14

Is that when someone has a gun to your head, and forces you to eat?

:smiling_imp:

(betsy.rome) #15

Carl, have you tested your post-prandial BG after your feeding window? if so, how long is it till the “peak” and what numbers did you get? just curious about trying this approach.

(Beth) #16

See I figured “unavoidable meals” was something like my Jewish friend eating “unintended bacon”. “Unintended bacon” is what happens when a Jew orders a bacon cheeseburger and… well, you know… you wouldn’t want that bacon to go to waste!!

(Bart) #17

Unavoidable meals are like a business lunch or dinner, where while you could not eat, it may seem rude to sit there while others are eating. Sometimes at certain reasturants even trying to stay Keto you still may ingest more macros or eating outside a window that you normally would have that day.

#18

Why is it rude. Isn’t it rude for people to eat when I’m not eating?

(Bart) #19

Guess you would need to be at that certain type of “business” lunch to understand, I am not talking family and friends

#20

It would frequently be considered rude to not eat if, for instance, someone else is paying for you (especially if that someone else is another company, but even if it’s your own company). In most cultures in general, if someone else is paying for you/providing a meal to you, it is considered rude or offensive to not eat something unless you have an exceptionally good reason (and no, “it will disrupt my diet” is not usually considered an exceptionally good reason).

But, for instance, we had a “team lunch” last week where once a month my work team goes out to eat together for lunch, paid for by the company, usually at a bit of a nicer place than we would normally eat for lunch. It would probably be considered rude or ‘un-team like’ to not go at all, and would be at least awkward if not slightly rude to go and not eat with everyone.