I’ve bee following this guy for a while and reading the science, I can answer some of people’s questions here, but i’m no expert on this at all
Matt Morsia:
THe interesting thing about IF is that you burn much more calories in the fasted state after about 12 hours into the fast, than you do normally between large meals. So we need to redefine fast. The fast between bigger meals is different from a fast beginning when you wake up in the morning after not having eatin for 12 hours. Metabolism increases 12 hours into the fast for many reasons, one is that your body burns ketones as well as stored glucose reserves. I found a study (PM if you want full text) that showed that we produce carnitines during the fast, and this allows the brain to even burn fat. So fasting raises brain and muscle metabolism basically (evolutionary advantage)
One of the coolest things about it is that you can actually consume more calories than you burn, this is related to the increased metabolism at 12 hours. So it’s much different comparing this to eating 2-6 times a day, as metabolism differs. THere could be a similar effect from eating only 2 meals a day however, but I don’t know.
Brooke: I’ve found that my morning workouts become much more intense when fasting. So you could switch a few of your workouts to the mornings when you fast, probably 4 hours after you wake up when you’re getting really hungry.
speedfreak – it’s a little more complicated than that. Small meals, or even better, a lack of food, can stimulate metabolism because the ciruclating hormones, like ghrelin, cortisol, and norepinephrine raise blood sugar. Larger meals can depress metabolism even through increasing orexin levels, which downregulate the waking cycle, but it’s more complicated than that too. A reason people are tired after thanksgiving may be because they ate a lot, not because of turkey proteins. Martin pointed to a study though that showed cortisol levels decreased in a fast though so once again IF is a lot different from regular feeding. It tends to optimize hormoes too, which means better metabolism as well.
Addicted to speed – see what works for you, for me it would be lunch, because I would skip breakfast and fast till I was hungry or until I worked out. But I don’t know what others have done.
I haven’t really had much success with it because I was vegetarian/vegan for a while, and longer fasts break down muscle tissue. If your last meal was rich in protein, then you can fast for longer as the amino acids will still be circulating (according to Martin). So now that I’m able to eat meat again ( i was at school and the meat is conventionally farmed there), I may try this again.
Unfortunately it was not easy to plan fast days. I always fasted on a whim, because I had more energy and was naturally not hungry. There are morning when I feel the carnitines in my brain telling my i’m fasting and I have a lot of mental clarity. So I guess it depends on what you eat. And I think martin recommends 16 hour fasts only, which is very easy. Doing that everyday for a month is something i have not tried yet but maybe I will starting tonight and I don’t think it’s that hard.