A curious question about keto and IF

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amusedmonkey
amusedmonkey Posts: 10,330 Member
in Food and Nutrition
I don't do keto, but out of general curiosity I have a question. I've seen people combine keto with IF (eating window). I've even seen people go for a single meal approach. Wouldn't having multiple smaller meals be a better approach to get into and stay in ketosis? I mean ingesting 100 grams of protein plus about 20 net carbs in one meal is surely going to have some kind of effect on blood sugar, or am I misunderstanding the process?

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  • yarwell
    yarwell Posts: 10,477 Member
    edited August 2015
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    It would need an experiment to see what the effect over 24h AUC values were. 30 g of protein per meal is probably adequate for anyone so I would probably lean towards 3 a day.

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3374835/ wasn't low carb - it just looked at meal frequency in healthy young subjects - "No differences between the frequency diets were observed on fat and carbohydrate oxidation. Though, protein oxidation and RMR (in this case SMR + DIT) were significantly increased in the LFr diet compared with the HFr diet. The LFr diet increased satiety and reduced hunger ratings compared with the HFr diet during the day." (LFr = low frequency = 3 meals vs 14 per day)
  • ki4eld
    ki4eld Posts: 1,215 Member
    edited August 2015
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    I personally couldn't do a single meal for 2 reasons: Volume, my stomach won't hold that much at once, but also because 20g in one meal could bump me out of keto. Most people stay in keto below 50g per day. My limit is closer to 30g.

    I do, however, limit my eating to about a 6-8 hour window, so I do engage in IF. My eating window is 12-7p most days, sometimes as short as 1p-5p. Granted, the shorter the window, the more protein-dense my foods and the fewer carbs I can ingest overall. I eat a few bites every hour during my eating window to get my protein, which is my #1 goal every day.

    I'm post WLS, but even before surgery, my doctor (bariatric surgeon specializing in weight loss) had some very specific guidelines for eating windows...
    14-16hr window: 3 small meals/2 small snacks with at least 2 hours between each
    6-8hr window: same amount of food, just eat a few bites every hour

    He said they accomplish the same thing as far as nutrient absorption. I'm going to believe that since he does this for a living, he's read the studies. I have not. If someone has info, I'll read it! I dunno how well nutrition does by cramming it all into a single meal. The system can do only so much with absorption before the food moves through. It's not like the absorption portion can hold onto food until it's done. Food moves at its own rate through the GI tract.

    I chose the 6-8hr window strictly as a personal preference. I don't like breakfast and rarely eat it, so skipping the morning is easy. I can't eat late at night. I need 2-3 hours between last food and lying down, else I get acid reflux. Eating in the short time frame, it feels like I'm eating a ton of food. If I had to stretch that out over twice the time, it'd feel like I'm eating half as much.
  • K_Anness17
    K_Anness17 Posts: 18 Member
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    You're not supposed to shoot for 20 net carbs a day. The point is to stay under it. The macros are 5% carbs 20% protein and 75% fat.
  • lemurcat12
    lemurcat12 Posts: 30,886 Member
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    kplacko0919 wrote: »
    You're not supposed to shoot for 20 net carbs a day. The point is to stay under it. The macros are 5% carbs 20% protein and 75% fat.

    Lots of people say net 50. It makes a huge difference as to how many vegetables one could eat, so 50 seems much more reasonable.
  • amusedmonkey
    amusedmonkey Posts: 10,330 Member
    edited August 2015
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    Interesting. So you actually can go out of ketosis. Other than ketones is the effect of ketosis measured by blood sugar or by insulin response? For example, someone may be able to take in 5-10 grams of carbs every hour with 1 gram eaten every 6-12 minutes without spiking blood sugar at all. I actually tested this to less extreme extent back when I was pre-diabetic. If it has to do with blood sugar then theoretically a person can eat up to 240 carbs and still be in ketosis, although very mild. Similarly a person who has a highly physical job could theoretically be in ketosis at a higher carb point if they lower it just enough to never store enough as glycogen and to still need ketones for energy. I guess my understanding is a bit fuzzy.
  • amusedmonkey
    amusedmonkey Posts: 10,330 Member
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    kplacko0919 wrote: »
    You're not supposed to shoot for 20 net carbs a day. The point is to stay under it. The macros are 5% carbs 20% protein and 75% fat.

    I personally feel it would be too hard to not make the most out of every gram of the allowed carbs. had a couple of eggs? 2 grams gone. Had a black coffee? Say goodbye to a gram - and forget it if you are a heavy coffee drinker. Even some hard cheeses have carbs. Artificial sweeteners may be lower in calories, but they still are mostly carbs. Sausages, cold cuts, most condiments even the low carb kind, some spices and flavorings like onion and garlic powder... etc. Trace carbs keep flying out of your budget until there is barely anything left for vegetables. It's a good thing many people consider 50 grams to be the cut off for keto. Leaves a person with much more freedom and room for more balanced micronutrients.
  • ki4eld
    ki4eld Posts: 1,215 Member
    edited August 2015
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    amusedmonkey wrote: »
    Interesting. So you actually can go out of ketosis. Other than ketones is the effect of ketosis measured by blood sugar or by insulin response? For example, someone may be able to take in 5-10 grams of carbs every hour with 1 gram eaten every 6-12 minutes without spiking blood sugar at all. I actually tested this to less extreme extent back when I was pre-diabetic. If it has to do with blood sugar then theoretically a person can eat up to 240 carbs and still be in ketosis, although very mild. Similarly a person who has a highly physical job could theoretically be in ketosis at a higher carb point if they lower it just enough to never store enough as glycogen and to still need ketones for energy. I guess my understanding is a bit fuzzy.

    Yes, you can go out of ketosis. I admit that my ability to explain KD is limited, but I'll try. My doctor referred me to these two articles...

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3945587/
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716748/

    Your understanding is about the same as mine. My question was, "Just how many carbs can I add until I'm out of ketosis?" and the answer is going to vary based on some of the things you mentioned, as well as each individual. Like any diet, it varies. A few of my friends stay in ketosis just fine at 50g or even 60g. One is like me and we need to stay 30g or even below. That limit can change based on various factors, so most who want to remain in ketosis drop below their threshold just to be safe.

    I'll assume you've heard of keto flu. Here's 2 doctors (1 bariatric surgeon, 1 endocrinologist) explanations as to why that occurs... My body has been given something that it can use easily for fuel... carbs. My body likes that, because bodies don't want to work. Work means using calories and lower calories means closer to starvation. Bodies are programmed to not like anything that puts it closer to starvation. So, if I give my body carbs (especially after it's adapted to using ketones), it sends signals that will reinforce the behavior it likes... easy fuel source. That's why the dizziness, nausea, headaches, body pain, etc. happen. We want to not be in pain, carbs mean less pain, eat carbs. Basically, your body can torture you for not doing things the easy way. The ketones aren't hurting me, I'm hurting me because carbs are easy and I like easy.

    ETA: I explain keto flu to show why someone would drop well below their threshold to avoid it. That extra 5 or 10g of carbs isn't worth going through a day or a week of feeling like crap.

    For some people, it's not a terrible reaction. For others, it can be pretty excruciating. I'm one of the "excruciating" ones, which is why it took me 8 months to drop from 120g to 40g and another 6 months to go from 40g to 15g. My bf went 150g to 30g in a week with no problems at all. Since I had RNY which causes malabsorption, I don't know how many of the 30g I'm actually absorbing. I could be getting 29g of the 30g. I could be getting 5g. There's no way to tell. I just have to play around to find the sweet spot, but pretty much everyone has to do that. My carb numbers are just going to look odd compared to what I eat. I was happy living around 15g, but they recently required me to up to 20g. We're looking for that sweet spot, although I thought 15g was pretty sweet!

    My doctor considers 50g the upper limit for ketosis, regardless of activity level, but recommends below 30g. Those numbers change slightly for RNY patients because of malabsorption. I can't say definitively why the level wouldn't keep going up if activity goes up. Maybe there's a point when the body just can't process more without blood spiking. Based on other information about nutrient absorption, that would be my best guess. It's the logical one.

    So, these are the laymen's explanations that I have. If someone can explain it better, please do. I'm always ready to learn!

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