This fasting caused a 37.4% reduction in caloric intake. It raises the question of whether it was the fasting itself or merely the overall caloric reduction that made the real difference.
> Of all the anti-aging and longevity-promoting interventions tested so far, calorie restriction (CR) seems to be the most conserved among species and robust. However, humans struggle to constantly achieve a certain level of CR. Here, we show in a clinical trial that a related intervention, alternate day fasting (ADF), also leads to striking reduction in overall calorie intake over the course of the study but is more easily tolerated than continuous CR and provokes similar beneficial changes on the cardiovascular system and on body composition while being safe for a period of >6 months.
Of course, there is no weight loss without a calorie deficit, but are all calorie deficits equivalent on magnitude alone? I struggle with the notion that the timing does not matter at all, and much of the suggested benefits of controlling the timing focus on other metrics beside immediate weight loss.
The "wisdom" of the late 90s was that six or so small meals were better than one large meal, with respect to weight loss. Now it appears some experts would argue the opposite. Is it all just a bunch of smoke and mirrors over calories in > calories out?
Digestion - and the ramping up of your entire metabolic process - is not a minor task. It is an all-hands-on-deck marshaling of a number of bodily processes that preclude other processes that you might like your body to engage in.
If you are firing up this mechanism every three hours - insulin response, spiking your blood sugar, moving your stomach and bowels, etc., then you never give your body time to do any other housekeeping tasks.
Think of food intake as an interrupt, in computer science parlance. What happens to process performance when you're throwing interrupts ?
IANAD.
For one, I seem to have a much higher chance of feeling tired if I eat a lot at once, compared to spaced out smaller meals. And two, this often manifests as me working/programming all day without eating anything until nighttime, having a huge meal, and then falling asleep. This typically leads to trouble sleeping, indigestion, and a general bleh feeling the next morning.
I've started moving to 2 - 3 smaller meals per day, and I find I have a lot more energy during the day, with no grogginess after meals and no issues with sleep. Though it seems a 24-hour fast gives me the most energy out of everything. And I agree continuous snacking is probably not great.
Do you have any links to describe what other tasks it would want to be doing in that time and which are blocked by an insulin spike?
"...it is theorized that cancer cells do not respond to the protective signals generated by fasting, thus leaving them vulnerable to both the immune system and cancer treatment. This process is known as differential stress resistance (DSR). Short-term starvation (STS), fasting for 48 hours, causes a rapid switch of cells to a protected mode, which is capable of protecting mammalian cells and mice from various toxins, including chemotherapy."
(et. al)
I read it as cleanup/housekeeping tasks that aren't high priority, relative to processing food inputs. When freed from those tasks, the body can concentrate on housekeeping.
Note that this was a fairly direct application of advice to diabetics on glucose control translated out of it's original context.
Too true. It was trendy as recently as a decade ago to eat many small meals and frequently "to keep your metabolism high." What no one was acknowledging was how the study that showed the relationship between fasting and metabolism had participants basically starve themselves for an extended length of time.
Unless you're a food addict, in which case you can trust me that neither time limitations nor discomfort is an obstacle to filling your gob.
(CR = caloric restriction)