I wondered this as well. In many of the intermittent fasting studies they kept caloric intake the same and showed that the benefits applied even when taking caloric restriction out of the equation.
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?
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.
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.
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.
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.
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.