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  1. GenGenimney

    Optimal Late-Life BMI for Longevity

    Not a chance on low BMI not signaling CR compared to higher BMI on a population basis. You can get low BMI in one of two ways: CR or physical activity (PA). There's a third, rarer mechanism: certain disease processes, like some cancers and hyperthyroidism. But again, that's rare. Most diseases associated with low BMI achieve this through lower food intake...or CR. PA doesn't actually differ a huge amount across cultures, especially when you exclude the extraordinarily, freakishly sedentary. Increasing intentional activity beyond a certain level decreases non-exercise activity thermogenesis to compensate in free-living people. The fairly tight cluster of body fat percentage with BMI testifies to this, too. So that leaves people mostly eating fewer calories, which is "non CR" that's really CR, though still not CRON. In cases of drug addiction, low BMI is typically a result of either loss of appetite, which causes CR, or loss of prioritization for food, which causes...CR. Making CR something other than restricting calories is beyond silly. It doesn't matter WHY you restrict--restricting is restricting, period. Intention doesn't matter. ON does, of course. And the disease itself matters, because if it's a respiratory disease or anorexia or weight maintenance or religious reasons, you'll get different outcomes, for sure. But not being one of a specially privileged group believing themselves to be part of some grand experiment doesn't magically make their restriction no longer CR. (Seriously, distinguishing between "food restriction" and "calorie restriction"???? Anorexics are practicing calorie restriction, guaranteed, and usually also food-type restriction.) If you want involuntary CR, there's been plenty of that historically, too. In certain countries, like Bangladesh and parts of India, girls are routinely underfed from childhood because they are considered to be worth less compared to sons. Recognizing this means you have to admit that CR's not going to get you past the age of 100 and change, even if practiced perfectly. And guess what? It's not. But the people on the opposite end are dying in their 60s (well, the super obese in their 50s), so I'm thrilled with the expectation of a high likelihood of a healthy 90s. Low weight resulting in high death in old age has been shown again and again to be related to a loss of lean mass. When the only exercise you get is from moving your own body weight around a little bit, as is common in old age in places with very sedentary retirement like the US, weight is protective because it increases your lean mass just a little. There are a number of studies, including tracking BMI over time and controlling for PA in the elderly (which is freakishly depressed in some places...like the US) that show no risk from leanness that isn't associated with lower lean mass. Keep a lean mass like a younger person through the healthiest diet, calorie quantity, and appropriate exercise that you can, and then you'll stay at the lowest risk possible in old age. There's nothing special about CR here except that we can be more methodical about the ON half. And we've already seen the maximum longevity that CR can get you. It's well within the 90-110 year maximum lifespan. Comparing ob/ob mice to humans makes no sense. We don't have appreciable numbers of people walking around with untreated leptin deficiency or any similar condition. Leptin deficiency inhibits puberty in people, and that tends to get noticed and treated. We can also see VERY clearly from hundreds of studies that in humans there's a pretty tight correlation between body fat and BMI. There are studies with over a thousand people, for example, that don't find a single man with less than 15% body fat or woman with less than 25% with a BMI above the overweight range. We have samples of 6000 people measured by DEXA scan in the NHANES that don't find even one extreme outlier--hardcore weightlifters are super-rare. There are no ob/ob equivalent clusters where at the same BMI one group of people is walking around "naturally" with twice...or half...the body fat percentage of other people. Even a 33% difference is incredibly rare and always, in the absence of severe, life-altering mutations, the result of deliberate and very high intensity bodybuilding. To get ANYTHING like that variation through genetics, you would have to isolate groups like those with Down or Prader Willi syndromes. You can't have something like that and just not know. The genetic contribution to weight among ostensibly normal people is no more than 10lbs, MAYBE 15lbs, with all known genetic variations apart from a severe syndrome stacked together. Our apparent genetic heterogeneity actually reveals an even greater homogeneity--there is a lack of breeding of groups of people to a specific purpose or mutation and a powerful regression toward a norm. The environmental pressures haven't been tremendously different for most groups of people across time. We might, MIGHT see some unusual results in genetically isolated Saami and Inuit populations, and maybe Australian Aborigines, who had extreme environmental pressures measurably different than most populations. But so far, even things like the Inuit's high levels of brown fat turned out to be, surprise surprise, entirely environmental. We're just not going to see wide variations, apart from genetic disease, in typical Afro-Eurasian populations. That means that BMI is an incredibly powerful proxy for caloric intake and physical activity at a given height and that these studies ARE meaningful, and to assume a special privilege because you're doing CR to live longer is very, very wrong-headed.
  2. GenGenimney

    Indications of CR status: Blood pressure versus BMI

    Another one, which is kind of crappy. Normal weight men and women who become underweight achieve lower blood pressure in spite of increasing age: http://www.nature.com/ijo/journal/v29/n6/fig_tab/0802944t4.html#figure-title This is part of the Nord-Trondelag Heath Study (Norway): The researchers examined changes in weight with changes in BMI. Again, it's one of the few that looks any anyone who is underweight. There may or may not be an inflection point at a BMI of 21 because "overweight" and "underweight" are such broad categories. I'm not sure how many people were in the underweight category at any point.... This is pretty rough and ready but interesting, nevertheless. Source: http://www.nature.com/ijo/journal/v29/n6/full/0802944a.html
  3. Working on my theory that we already see plenty of CR (but very little CRON) in the wild, where is the point that BMI results in much lower blood pressure, and at what BMI is there no longer a positive effect, understanding that there are confounding variables in population studies? It's hard to find studies that don't just go "BMI <25," but I did find one that not only showed values for every BMI point but was also a study of lean populations (in Africa and the Caribbean) AND went down to a BMI of 17! http://hyper.ahajournals.org/content/30/6/1511.full For men, BP had a positive correlation with BMI all the way down to a BMI of 17. For women, it leveled off at a BMI of 21, mostly due to much higher BPs for the lower BMIs at ages above 45, but the correlation under the age of 44 is, if anything, even more dramatic than that of the men's, so I'm tentatively suggesting lifestyle factors at play here (maybe increased sarcopenia/increased fat percentage after age 44?) but also likely a BMI-dependent floor on BP, with any further decrease dependent more on, say, nutrition. The authors said: THey pooh-pooh the idea that BMI itself is to credit/blame: But while PA EE and leanness are traditionally linked to lower BP, I don't think we should discount lower BMI due to CR versus heavier people. The PA EE in studies I've seen is quite a bit lower for men below a BMI of 18.5 in Africa specifically (sorry, don't remember the studies). So there's no answer here...but maybe there's a suggestion that "CR" probably shouldn't be thought of as a switch but rather as a continuum with the extremes obesity on the other end. There is no flat then asymtoptic curve here, even though the study included moderately underweight people, into "lower PB." Instead, it was a gradual, linear slide (at least until a BMI of 21 for women.) They speculate that the overall BMI/BP graph would be sigmoid, and that surely seems the most likely. The BMI of 21 for women may be that point under the nutritional conditions of those populations.
  4. I've been gone because I forgot my password and was too lazy to reset, and I'm still quite skeptical (perhaps MORE skeptical, honestly) of the benefits of extreme CR in humans. (Sorry/not sorry.) Buuutttt since my target weight is a lean 17-19 BMI, and since I want to keep doing ON regardless, I guess I'm a non-CRONie CRONie or something. I've been puzzling over "What IS CR?" off and on for months, and then suddenly I remembered an article I read a few years ago that might have an answer: "Constrained Total Energy Expenditure and Metabolic Adaptation to Physical Activity in Adult Humans." http://www.cell.com/current-biology/fulltext/S0960-9822(15)01577-8 For some reason, my screen capture plugin doesn't work on the site, but anyway, researchers found that "calories out"/TDEE doesn't vary a whole lot among different populations, even with very different lifestyles. Their basic model came up with a figure of 2309+/-38.4 calories, when controlled for a number of things. I'm not sure how to use this, fully, as many of the things that are controlled for (like fat mass/fat free mass) are obviously altered by intake. I think we can probably say that around a BMI of 25 is probably an honest ab libitum number, without food shortage and with normal levels of activity. (Looking at worldwide average BMIs: http://visual.ly/weight-world) Then you could plug in that weight into the typical age- and sex-specific body fat percentage to get the rest of the info you need to calculate a baseline TDEE: http://halls.md/body-fat-percentage-formula/ That would give a woman my height (5'6") a baseline of 2007 cal/day, with no physical activity. The minutes per day of physical activity threshold is 200, so plugging in 200 (assuming this give you the body's happiest level of activity), I end up with 2288 calories as the ad libitum value with a steady weight (though I should probably add a tiny bit to that for "better" foods being less efficiently processed...). 200 minutes per day of light activity is another 280 calories for my size, which is above light but under moderate exercise. A 10% CR would be 2050 calories TDEE, which would be, interestingly enough, a BMI of 18 with heavy exercise or 21 with moderate exercise or 27 with light exercise. A 20% CR would be 1830 calories, or a BMI of 13 (aka dead) with heavy exercise, about 17 with moderate exercise, and 22.5 with light exercise. A 30% CR would be 1600 calories, or a BMI of 11.5 (aka dead) moderately active, 16.5 lightly active, and 22.5 sedentary. (Add on a little for inefficiencies of digestion.) We know that caloric restriction that extends life does NOT reduce daily activity in mice. It seems reasonable to assume that the maximum human caloric restriction would be less than that requires to maintain somewhere between a light and moderate activity level, possibly a fully moderate activity level. This in turn means that no more than a 30% CR would be safe for humans, and that the baseline TDEEs are probably higher than what we've previously assumed. A 10-25% CR from the "free-living" ad libitum values for typical healthy human populations with light to moderate activity would be a level that most people wouldn't feel the need to conserve energy, which would be contrary to the animals who have benefited from CR in the past. I think we DO see that in the mortality curves of healthy people with low-normal/high-low BMIs, and I think we hit a TDEE wall above a CR of about 25%. People tend to maintain their weights and intakes less scientifically than researchers do for mice, so the curve might be a bit more generous if you are stricter about it, but that's all. These figures do bring up the suggestion that CR really does happen fairly frequently "in the wild" among humans, which would bolster my contention that there probably is pretty limited benefit, a benefit we already see not too infrequently today, of no more than a 2-10% lifespan increase. In humans, this would be dwarfed by other factors (like the ON side of things!!!). We don't see that people who sit on their butts and stay at a BMI of 17 live a lot longer than people who workout and have a BMI of 20, for instance, much less that people with a BMI of 18 who work out die younger than people with a BMI of 18 who don't. If people were like mice in this way, they should! Even if we assume a baseline BMI is 22 (which we don't really have evidence for), we still should be able to see some level of trends with that. Anyhow, this is a bit babbly, but anyway, a few things to chew on.
  5. There seems to be some confusion about possible mechanisms for continuing fecundity in mice under CR into old age, and I've seen suggestions in various places that CR might theoretically extend fertility in women. This isn't possible. As far as reproduction goes...mice aren't human. Here's an overview of folliculogenesis: https://en.wikipedia.org/wiki/Folliculogenesis Other than the solid overview, a point of interest is under "number of follicles." The short version is this: Humans don't produce more follicles after birth, period. There is also a common misconception that I've seen that an anovulatory woman is somehow preserving/reserving her follicles for later recruitment. This also simply isn't true. Follicles are recruited continuously into the first stages of development roughly a year before ovulation. If they pass through the upper stages without being subject to the right dose of FSH for recruitment into antral follicles, they will simply suffer from atresia and die. Similarly, the "best" of the antral follicles--meaning the one that has the most FSH receptors at the time of FSH increase--will be the only one large enough to respond to a surge of LH and burst, causing ovulation. Amenorrhea from any cause doesn't prevent or slow or otherwise attenuate the first stage of follicle recruitment. Therefore, it has zero chance of either extending fertility or delaying menopause. Damage to the ovaries, often from a chemical insult, can lower the number of primordial follicles and can potentially speed up menopause because low ovarian reserve is a major trigger for menopause. Two major causes of a low number of primordial follicles are high androgens in utero and chemotherapy. Regardless of one's starting place, as the number of follicles for recruitment are depleted, so is a woman's fertility. This process begins in one's early 20s--yes, early 20s!--and is complete by age 45 in most women. Women need to understand that there is no benefit whatsoever from amenorrhea from any cause whatsoever to the aging process or to fertility length. That said, amenorrhea can be perfectly normal and healthy--obviously during pregnancy but also during breastfeeding--and there is considerable benefit by lowering the risk of "female" cancers in this type of amenorrhea. However, amenorrhea from PCOS or from low weight/exercise/stress is pathological. In the case of true, classic PCOS, it shows up with insulin insensitivity. In the case of low eight/exercise/stress, it can rapidly deplete bone density, which can cause crippling and even deadly complications beginning as early as shortly after menopause, which will occur the same number of years after puberty regardless of your menstruation status.
  6. GenGenimney

    calories: how low is too low?

    Argh, I need to add... 1000 calories minimum for SHORT TERM weight loss only, and your max deficit (difference between eat and burn) should be your fat mass * 27, which has to do with the maximum rate of fat mobilization (which is 31+/-3 calories per pound). Right now, my max deficit is 810 calories, so I'm usually eating a lot more than that because I'm active. Your individual maintenance will be much higher than that, but how much higher depends on your activity. I was eating 1700 cal a day and was fat because I wasn't active. (Estimated from what I was burning per day, measured well by an activity tracker, and the fact that my weight didn't change.) I've up my activity by a solid 400-500cal a day, now, and would be nice and slim at 1700 calories a day. "Enough protein" at rapid weight loss and that height is 60-100g a day. Check out the "body weight planner" at the NIH to determine how fast you would lose and what you would get to at different intakes. A BMI of 15 or below is in the "absolutely bad, you're starving, don't do that" range. You're unlikely to be in CR with an BMI above 23. 18.5-20 is a possible optimal range, but there are so many confounding factors that benefits for a healthy person might continue to accrue down to 17 or so. I'm pretty hesitant to declare this as fact. You should definitely closely track all your health signs starting at a BMI of 19.
  7. GenGenimney

    CRON-o-meter: supplements

    I'd already read those. LOL. Before seeing those, I had already read the abstract of the rodent study, too, where they used 4%, 8%, and 12% glycine to balance .4% methionine, and only the 8% and 12% worked. So I was thinking of shooting for getting 20x glycine to methionine, especially since it's such a good sweetener for strongly-flavored things like yogurt. The LS extension wasn't terribly impressive, but combined with moderate long-term CR..... (Due to my family history, and CR beyond the point where my bones start to lose density is a HUGE, SCREAMING no-go. Both my grandmothers died from osteoporosis complications, and one was crippled by osteoporosis for a long time before she died.) I used to make broths and soups all the time from the skin and bones of poultry that we bought, but I'm far too lazy now.
  8. GenGenimney

    CRON-o-meter: supplements

    Only slightly off topic... I can't find calorie info on glycine, but I assume as a protein it's 4kcal/g? Is that right? The one study on methionine "restriction" through glycine supplementation has the ratio at 1:20 as the threshold successful level. Most of the foods that I eat naturally have 1:3 (animal) to 1:4 (plant) ratios. I'm eating 1-2.5g methionine right now. That'll go down quite a bit when I switch out the Greek yogurt for regular after I've stopped working on losing weight and go from 60-80g protein/day to 50-55, but it will probably never be less than 1-2g, which needs 20-40g glycine to balance, out of about 3.5-7g glycine I'm getting now. Yogurt is pretty awesome with glycine--I was using stevia to sweeten, but glycine works just as well, and I can do a tablespoon in a cup for 12g of glycine. Lentil soup can't take more than 1tsp/4g. Might try some in tea, which I usually drink black....
  9. GenGenimney

    Cronometer Question

    Is there a way to set daily calories by hand? I've played with various sites for tracking food, and I like all the detail with cronometer, but it GROSSLY over-estimates my daily burn, and if I'm doing CR long-term, I'm going to have a daily food budget that's not going to change with activity. EDIT: Okay, with the FitBit syncing AND with it set to no activity, the overestimation isn't bad at all. I still need to be able to set calorie targets by hand, though!
  10. Well, CR is going to be harmful to ANYONE below a certain threshold. Deficits don't last forever. So if you're at a set point that's in the CR range, then lowering your intake more and creating a new deficit could push you past the benefit zone into a starvation status. Starving ain't good. The HUUUUUUUGE question is...CR based on what normal? I have a sneaky little suspicion here, given that rats don't get medical intervention the way people do, that the normal lifespan of humans is probably about 75-80 years, while CR can boost the outside to 105 or so. The differences are more modest than in mice, but since they already age so quickly, that's to be expected. We don't get pretty little graphs of CR versus controls in the wider population because there is no true, clear control--we have everything from substance abuse of various sorts to tremendously bad diets to good diets but too much confounding everything. But I think there are people walking around right now with CR-consistent blood work, BPs, arteries, and RHRs who have no idea that they're doing anything special. I had that for YEARS. I'd heard of CR (because I hear of a lot of things) but never imagined that I'd be in it. My BF% ranged from 10%-16% in that time (again, woman here, higher numbers). I had a low-protein diet, but it was pretty high on refined carbs. (I was an 80s kid, what can I say?) I've never been below a BMI of 18.5 as a teen or adult. I was was normal weight/lean. I've measured body temp--I'm using a thermometer that corrects to 98.6, but it still gives the right temp-below-normal from that--resting heart rate and blood pressure so far. Once my blood pressure is down to 90/60 or below consistently and my RHR (I'm a woman, so mine runs higher) is below 50, I'll be in the zone as far as that's concerned. Some people are looking at fasting and post-prandial glucose, too, so I grabbed a $10 kit. I have NO idea what I'm looking for there, though. LOL. Subjectively, I feel hot, sweaty, and miserable all the time with "normal" temperature. Now that it's dropped a little again, I'm more comfortable. When it's quite low, I'm slightly cold at temperatures other people like, so I always used to bring a coat everywhere. I adapted weirdly well to working in high-temperature conditions. As an engineering intern at a paper mill (floor temps vary from 90/95 degrees in the ware house to around 120 in the basement where all the pipes are), I didn't sweat at all on the floor after a couple of weeks and only got hot in the basement. I wore a winter coat in the labs and the offices, though, and I took any work I could out in the factory. Everyone there thought I was a bit of a freak for it. People who had worked there 20, 30 years were red-faced and fled back into their climate-controlled viewing rooms. And I was actually comfortable. At home, I had my AC set to 85, and visitors thought it was broken. At that time, I had a BF% of about 10%. I ran to the mill's clinic once because I slashed my finger on my mailbox on my way into work one morning, and the nurse just about FLIPPED OUT at my body temperature--it was 96.8 orally. He wanted me to get checked out at the hospital. I do exercise quite a bit. I walk on a treadmill when I work and do 1hr-1:15 of exercise 6 days a week. I'm personally VERY concerned about osteoporosis. Both of my grandmothers died from complications of conditions caused by osteoporosis. So I want a baseline DEXA scan, and I won't restrict to the point that my menstruation stops (though I've always been on a looooong cycle). Significant to protein: Post-menopausal women are protected by higher levels of protein, specifically plant protein, from osteoporosis. Both men and women have longer lifespans with lower protein before 65 years of age and higher protein after.
  11. GenGenimney

    CR Staple Food

    I just quarter and roast them. :) Spaghetti I scoop, the others I take off the outsides. I can also eat the seeds, which I lurve. (I don't remove the shell--talk about WORK!!!) Sweet potatoes--peel and then usually Spiralize. Takes a couple of minutes but not long. Pan-saute with a bit of olive oil. I make up a bunch at a time and eat it over several days. Not quite as easy as broccoli and greens, which I usually steam in the microwave right before eating.
  12. I don't have my baseline BP...but I checked it today, and I'm back down to 97/60. High-ish but not scary-high, like it was before. Resting heart rate is running a little high at 54 BPM, but I'm in quite a bit of pain today because I hurt myself yesterday, so I can't expect it to be 50-52, as it is now when I'm not hurting. (I have chronic pain, and my BP and RHR variations reflect that.) ETA: I'm still pretty grotesquely over-fat, with 23% BF. At 20% BF, I SHOULD start seeing truly normal results again for me. For fun, I picked up some ketone urine strips. I didn't know it was so easy to check for ketogenic states!!! I really want to examine the assertions of people that 12/12, 16/8, or 18/6 unfed/fed can induce temporary ketogenesis. Should be fun....
  13. I'm glad I wasn't missing anything! I can't remember numbers, but my triglycerides have been exceptionally low in the past, too. I have a sleep disorder (non-24), and the only time it goes away is on CR/low body weight, so I'm trying to get back to that for those reasons, too. It's quite annoying otherwise. (I joke that I'm just on a slower rhythm than the rest of the world. I got teeth slowly, I grew slowly, I finished puberty years after other people--who's still gaining height at age 21????, I entrain to a nonexistent 26-hour day, my cycles are longer than other people... But at least the sleep cycle thing can be influenced by body weight.) I suppose what I should do is measure everything CR-related and see if it goes into unusually low zones, and that would be a good indication.... I'll be at 40% restriction for about another month, then down to 30%. We'll see what my body weight is doing a month after that.
  14. GenGenimney

    Short-term food shortages and CR'd populations

    In the state where some people forage for food NORMALLY--both Okinawa and Ikaria have this profile, as Buettner made a bog honking deal about how they both eat lots of native microgreens--they might not been as subject to vitamin deficiencies as in other places, too....
  15. GenGenimney

    Elevated fasting glucose

    I think that's right. There's some evidence -- despite the studies showing the merits of the Mediterranean diet -- that even MUFA might be harmful in some ways. People in most (all?) long-lived cultures don't actually eat a lot of fat, but they are highly non-sedentary (which doesn't mean they're out jogging; they're just very often in motion). Be wary of Buettner's BS line about how they don't do intense exercise. As an over-privileged, soft-living first-worlder, he's evidently never chopped wood or cleared brush with a machete. He also seems to think that the fact that he lost an arm wrestling contest with a guy who's over 90 is just evidence of high levels of "constantly moving around." NOPE. It's vigorous activity and heavy lifting. Okinawans do formal martial arts. Seventh Day Adventists go to the gym. Ikarians, Sardinians, and Costa Ricans ALL chopped wood daily for wood fires IN HIS ACTUAL BOOK. Watch carefully what he describes versus the lessons he takes from them. They are often quite different.