From what I’ve been able to find there is fairly good evidence for reducing one’s diet by about 25% from the recommended caloric intake.
What I cannot find (most of what I’ve tried to find is abstract only and the papers behind a paywall) is if the pattern of intake matters. In other words, does the approach required that one leave every meal a bit hungry?
I have no problems skipping meals, sometime two even, but find it more a challenge to put the fork down once I’ve decided it is time to eat.
So if I wanted to try following the approach clearly one way would be much easier for me to implement than the other.
Anyone having any insights or specific references that have looked at the claims from this particular perspective?
Answers that say it’s not clearly the case disspite what people like Sinclair or the earlier experiments say also welcomed.
Take a look at the Fasting-Mimicking Diet, which has some decent evidence going for it. It’s a 5-day period of low calorie consumption with restricted carb and protein intake, repeated every few months.
Some people actually think the benefits of caloric restriction (to the extent there are any benefits in humans beyond just avoiding overfat) may result from incidental intermittent fasting. I’m no expert but my fairly vague understanding is that the re-feeding period after a fast promotes some kind of cellular repair process that doesn’t occur if you’re continuously well-fed. I guess people who restrict calories overall would generally get little doses of this every once in a while as their food intake fluctuates by chance.
Thanks.
That is largely what I’m getting from Sinclair’s Lifespan. What it seems to do, if I’m following his claim, is the restricted diet puts the body in a stressed mode (not malnourished state, that is to be avoided). The switches on come cellular activity that shift energy from cell division to cell maintenance and cleans up a lot of the garbage (malformed and miscoded proteins).
He also suggests that the other thing to diet wise it reduce the intake of some of the essential amino acids. We get too much of those and they are all associated with activating an enzyme that promotes the cellular division activities and away from the garbage collection and maintenance work.
I had not gotten to this point when asking the question but the book also goes on to say that a lot of different structures to the diet, each meal lite, fast a day a week or so, skip meals… all seem to function the same. Not surprising as all put us in a stressed mode and then the cell functions react. But he was not sure if some are perhaps better than others.
I don’t know if he has identified a gear, or or the as the book seems to suggest, for aging but interesting so far.
Like other interventions, effect sizes shrink dramatically moving from non mammalian to mammalian, and again from mouse to primate, and again from primate to human. There’s a paper about why this is unsurprising (something about the metabolic pathways being affected are what you’d expect to be affected in short vs long loved species) but it’s been years since I read it and I’m not sure what the keywords to find it are.
Thanks and it is a good thing to keep in mind.
Got some hints there at least ;-)
I’d first start by questioning what evidence you’ve seen that would convince you that calorie restriction is a good idea?
I’ve seen zero studies in humans that would indicate this. The negative side effects are huge, and little evidence for significant gains in longevity.
There was a good discussion of this on the SSC blog last year: https://slatestarcodex.com/2019/12/12/acc-does-calorie-restriction-slow-aging/
With regards to meal timing, I’ve been keeping an eye on the research for over a decade, and in short it makes very little difference.
Quality and quantity of food are what really matter.
That said, both the research and what I’ve seen anecdotally do indicate that there is huge individual variability in how people do on different diets.
Typically by following some arbitrary rule (I.e. avoiding food group x), dieters inadvertantly reduce their calorie consumption.
Most diets ultimately fail either because people miss said food group and return to eating SAD or find some way to “cheat” (gluten-free cakes, vegan cheese, etc), not realising it was the calories that were the issue, not the “evil” food.
Time restricted eating plans work in much the same way. By limiting the hours during which you allow yourself to eat, you typically reduce your calorie intake, particularly in the short term.
As with other methods, however, we humans are very good at adapting by eating bigger, more calorie dense meals over time to compensate!
My personal experience of various different modes of intermittent fasting is that it does have some advantages:
It teaches you to recognise true hunger
Often we eat when we’re not really hungry. After a few 24 hour fasts it becomes much easier to turn down junk food if it’s the only option and wait till you can find something better.
Less cooking and washing up
Though I actually enjoy the cooking part, eating just 2 x per day does save considerable time and effort.
Can eat larger/more calorie dense meals.
Of course you have to be careful not to over compensate! But if you’re going to eat 2000 calories personally I prefer 2 x 1000 meals to 4 x 500.
All the above for your average person.
If you’re a high level athlete, or a bodybuilder, there’s further questions of meal and micronutrient timing around training, and yes if you’re looking for every tiny gain in physique and performance these can make a difference, but I don’t think for most people it’s worth worrying about.
I’m no dietician, but I do know that the pattern of intake makes a difference. If at a given time, you eat everyday, your body will become regulated. For example, if you eat at 10am, 1pm, 4pm and 7pm, your body becomes accustomed, in turn, burning the calories off faster because it’s preparing itself for the next meal as expected. When patterns aren’t in place, you body stores the calories in fear of not knowing when the next meal will occur.
You don’t have to leave your meals hungry if you control your portions and use food for fuel instead of pleasure. Practice it and your body will expect less at a given time—but maybe more over an extended period: having small meals more frequently throughout the day. (I am a foodie, so this was an extremely trying task, but with practice-and a cheat day or two- I mastered it).