Is there a time of day better to fast

(Davis Smith ) #1

Sorry Newbie question. I am starting to understand IF. fasting from 8pm-to noon the next day, is that the best time, is it best to do it in the middle of the day. Or does it all depend on the schedule. I figure I can get away with a coffee with MCT in the am, to get me to Noon for lunch. Thanks for any advice

(Todd Allen) #2

I originally found it easier to skip breakfast. I tended to not be hungry first thing in the morning and a cup of tea or coffee was sufficient to make it to lunch. But Iā€™ve read several things that suggest it is better to eat breakfast and skip dinner - ones insulin sensitivity tends to be better earlier in the day, it tends to better reinforce circadian rhythms and enhance sleep and it tends to result in lower blood sugar while sleeping which can enhance growth hormone and its effects on burning fat and building muscle.

So I made the switch and started eating an early substantial breakfast despite not being hungry, eating a modest late lunch and skipping dinner. It was a bit of effort the first few days but rapidly became easy. My sleep is much improved and Iā€™m waking up consistently at dawn without an alarm and hungry and ready to eat by the time I make it to the kitchen. And Iā€™m no longer significantly hungry in the evenings and find it easier to get to bed and get to sleep at a consistent early time. Iā€™m losing fat faster with minimal effort - dropping nearly a lb a week with roughly 13 lbs remaining to my current goal of 12% bodyfat, while strength and performance are increasing.

But we all are different and have different circumstances and trying multiple approaches each for a week or two to see what suits you best is probably the way to go.

#3

Iā€™ve wondered the same thing! I was skipping breakfast before doing keto so I think now, based on Toddā€™s answer that I may try to rearrange and skip supper instead.

(Katie the Quiche Scoffing Stick Ninja ) #4

You can do it however you wish to do it and whatever is easier for you.
People typically fast from dinner to lunch the next day as you are sleeping for most of that fasting period so it helps to adjust.

(Doug) #5

Easier to skip breakfast for me too, but most of us have a substantially higher and longer-lasting insulin response to eating late in the day, versus eating early. All other things being equal, itā€™s best to be fasting through the late-day hours.

#6

I think @OldDoug is right for most people (as he notes), but new information suggests that about 20% of us have an evening-oriented chronotype, which shifts your natural circadian rythm to later in the day (and all of the resultant hormonal fluctuations). So, definitely depends on the person. In any case, I believe when you eat is far less important than what you eat.

#7

I think the science is pretty clear that WHEN is more important than WHAT with regard to addressing metabolic disorders. Thatā€™s because feeding and fasting are strong stimulants of hormones like insulin, glucagon, cortisol, leptin, and ghrelin. All foods will trigger a response, itā€™s a matter of degree.

In The Complete Guide to Fasting, Dr Fung states that eating a LC diet provides only 80% of benefit derived from fasting. Vlogger Bob Briggs has a video describing how eating a LC diet wasnā€™t sufficient at lowering his basal insulin levels so he needed to implement an IF protocol.

Personal testing can be enlightening. Since at home hormone testing is impractical for providing actionable information on a timely basis, I use blood glucose as a proxy. Iā€™ve found that fat bombs with minimal carbs, will elicit a response if eaten in quantity (1000+ calories).

#8

In this case the ā€œwhenā€ I was referring to was time of day (vs. how often you eat). I am big on fewer meals and fasting and so happen to be 40 hours into a 72 hour fast right now. :grin:

(Carl Keller) #9

The Big Breakfast Study suggested the same:

A growing body of evidence highlights the importance of the biological clock as a modulator of energy balance and metabolism. Recent studies in humans have shown that ingested calories are apparently utilised more efficiently in the morning than in the evening and this is manifest through improved weight loss, even under isoā€energetic calorie intake. The mechanisms behind this enhanced morning energy metabolism are not yet clear, although it may result from behavioural adaptations or circadian driven variations in physiology and energy metabolism.

But from force of habit, I canā€™t find the hunger or motivation to eat a breakfast of any size.