How much does something such as a small amount of fat and scant protein disrupt the efficacy of fasting? So say, a couple of pieces of very fatty bacon or a handful of macadamia nuts? Also, I have heard that the physical stretching of the stomach can raise insulin levels. So would drinking a lot of liquids during a fast result in insulin levels rising?
Fasting questions- insulin levels
brownfat
(Todd Allen)
#2
I’ve been playing around a lot with fasting in various forms and durations. I’m not very good at true fasts, water only I rarely get past 3 days. But I find that by consuming small amounts of various things I’ve been able to do 2 weeks at a time. I’ve just embarked on my “Oktoberfast” where I hope to remain in a near fasted state for the entire month by eating one small meal each day, typically 400-500 calories. I plan on mixing things up with a wide variety of foods and some days eating mostly protein, others mostly fat and even days that are mostly carbs, low glycemic vegetables and fruit, and tracking how I feel. On my last fast I threw in a couple days eating 100+ g of such carbs and stayed fairly deep in ketosis. One thing to watch out for is that eating a small amount of food can sometimes spike hunger and you may need to experiment both with the foods and the timing to find what works best for you.
If you search for “Valter Longo fasting mimicking diet” you can find a lot of information from him studying people doing 5 day “fasts” while eating fairly low calorie - on the order of 500 to 1000 / day, mostly restricting protein.
Protein in some ways is the most interesting macro - a lack of it switches the body into a recycling and repair mode initiating processes such as autophagy and a surplus initiates growth. We need to engage both modes for optimal health though it is not clear what is the optimal balance. Longo’s research finds many if not most people find his regimen far more doable than genuine water fasting. And it appears to still yield many benefits, though perhaps not as much as a true fast.
As far as insulin goes, track your blood sugar. If your blood sugar stays low anything that stimulates insulin will have a brief modest impact. Foods that elevate blood sugar for a sustained period are the biggest problem. If you are eating keto your blood sugar should stay low unless you have other factors like stress driving it high.
VLC.MD
(VLC.MD)
#3
Maybe, maybe not.
Probably 1/50 th of what a banana would do.
I’m eating smaller volume salads now … so I’ll test your theory. 
Emacfarland
(Erin Macfarland )
#4
I can go 18, 20 hours most days with coffee, salted water, tea…but occasionally having a small fat based snack will help ease low energy. I keep it low protein because im aware of the impact of it on autophagy. Then I can make it until the evening when I’ll have a meal.
Emacfarland
(Erin Macfarland )
#5
Awesome! Let me know! I wonder because sometimes I feel full when I drink hot tea or warm water with salt. I know the stretching of the stomach does release insulin based on what I’ve heard from several podcasts.
justme
(Linda Culbreth)
#6
On such low calories while otherwise fasting, I would be concerned that the basal metabolism rates would decrease. Have you read Dr. Jason Fung’s Obesity Code?
https://idmprogram.com/books/
Emacfarland
(Erin Macfarland )
#7
I have! My caloric intake is more than sufficient, I don’t do long fasts and I eat every night
VLC.MD
(VLC.MD)
#8
I read both books - including the fasting book. But only parts of them. The real metabolism killer is eating lots of carbs while on a 1,000 calories diet for months.
Small food to keep you fasting isn’t the problem.
Carina
#9
Won’t this have the same effects as calorie restriction diet? I understand people that use this approach to do the 5:2 diet, or for three days fasts followed by feasts, but if you constantly eat 500 cal every day for a month won’t your base metabolic rate just drop to accommodate?
Saphire
#11
Its a good question, perhaps the key question. Depends on what you are eating (mostly fat, not much carbs, some protein) and whether you have fat available (31calories per lb of body fat per day according to @richard). Assuming you are not eating carbs so are in ketosis and can access stored fat, then your body (so the theory goes) cannot tell if the calories are coming from your body or from an outside source so it does not go into starvation mode.
A couple questions I have on that, if it really cannot tell, then why do you go into a heightened mode when fasting, you become more alert, presumably so you can find a deer to hunt and kill for your sustinance?
How does your body replace amino acid proteins that are essential if you are doing a 500 calorie keto diet for a month? At some point you run out well before the month is up. Is autophagy really enough?
brownfat
(Todd Allen)
#13
I’m monitoring my body temperature as a proxy for base metabolic rate. And I engage daily in activities where I can measure my performance such as swimming, biking, stair climbing and weight lifting. If my temperature or performance drops I’ll back off the calorie restriction until it rebounds and then continue with the near fast. My daily need for calories has dropped a lot and I expect it to drop further and I’m fine with that so long as my vitality, energy level and performance are increasing.
I had a dexxa scan on July 21st which showed I had 45.9 lbs of body fat and since then I’ve lost 20 lbs and I think I’ve gained some muscle. I’m guessing I have about 25 lbs of body fat remaining and would like to lose roughly half of it and then focus on regaining weight as muscle.
There has been a fair amount of discussion in other threads here of the maximal rate at which bodyfat can be burned, ie how much of a caloric deficit we can sustain before we become energy deprived and our body cuts energy expenditure in undesirable ways that is sometimes referred to as a lowering of BMR. I find signs this is happening when water fasting after 3 to 5 days. I’m now trying to fine tune my fasting for the max sustainable rate of fat burning without crashing by eating just enough to sustain the fast until I make my goal.
marklifestyle
(Mark Rhodes)
#14
The rate should decrease while fasting because you are not using the digestive system during fasting days. As I understand it, the body recognizes the lack of energy coming in and makes the digestive system run on minimum power thus sparing energy for other more crucial areas. This lowering does not affect the other systems as the allocation for respiratory, brain etc all receive what they did prior to the fast. The problem with daily limited calorie is that the digestive system needs to be run, sometimes with more energy than what it is being asked to process and here then the body re-allocates from oh say the immune system to cover the expense of digesting that morsel. When the feast begins again the digestive system turns on and the BMR goes back up to previous or elevated levels.
justme
(Linda Culbreth)
#15
For clarification in my answer. fasting is not the same as low calorie. According to Dr. Jason Fung, fasting does not lower Basal Metabolic Rate, low calorie does.
VLC.MD
(VLC.MD)
#17
From memory: Fasting lowers the metabolic rate LESS than Calorie Restriction. But does a little bit.
Obviously you would suspect that no calories impacts Metabolic Rate more than some calories … but that doesnt seem to be the case.
Q: is fasting good ?
A: It is the best way to lose weight. IMO.
justme
(Linda Culbreth)
#18
It’s also the best way to lower insulin resistance and raise insulin sensitivity.
afblangley
#19
According to Jason Fung, fasting increases BMR (Complete Guide to Fasting table 3.1), by increasing adrenaline and growth hormone. He compares it to bariatric surgery, which also doesn’t decrease BMR, beyond that associated with a having a smaller body.
Fung says insulin is the driving force behind fat loss and fat gain. I interpret this to mean that anything that increases insulin, which includes all foods (to varying degrees) is counter to fat loss. He says a low carb diet provides 71% of the benefit of fasting. In the next paragraph he says that a low carb diet can reduce insulin by more than 50% but fasting can get another 50%.
He goes on to say that restricting some foods all the time is different from restricting all foods some of the time.
I think one of the key variables that tends to be forgotten is that folks who greater insulin sensitivity have more flexibility in that modalities work for them. Those that are more insulin resistant have to be more strict to achieve results.