Intermittent Fasting

Starrynightgrl45

I have read that intermittent fasting could be useful for boosting your metabolism. Could this be done through not eating your calories back a day or so a week and having a particularly heavy workout? Would anyone recommend this? If I follow up a low calorie day (due to extra exercise) with a higher calorie day (sticking to my MFP goal for the day) would it help?

BackTatJIM

Meal timing has nothing to do with boosting your metabolism. IF can be great for cutting of bulking if it fits your life style butthere is no short cut to losing weight. If you would like to boost your metabolism then exercise and eat enough food.
Great video on meal frequency here :
http://www.youtube.com/watch?v=Emstd5Ipd-M

lambchristie

In my opinion, from what I have read on this topic on MPF, the term 'fasting' is used in the wrong context. Just because you are skipping a meal does not meal you are fasting. Intermittent fasting = skipping a meal which is not a good idea for any weight loss program. You need to always refuel your body, especially if you are exercising each day and burning calories.

Do yourself a favor and keep to a regular meal plan and keep moving forward.

ShellBell4281

IF doesn't boost your metabolism but it doesn't lower it ether. I'm a big fan of IF. google Eat Stop Eat, Fast 5, Roman Fitness System.

CristinaL1983

Intermittent fasting is based on the fact that certain hormonal/chemical changes occur in your body when it is in a fasted state. HGH is higher, insulin sensitivity is higher, stem cells are more prevalent in the body (leading to faster healing times) etc... Your body cannot be in a fed and fasted state at the same time. Cutting calories (by not eating back a heavy work out) is not fasting.

IF does not impact your metabolism. Fat oxidation is higher when there is no food in your system (which is obviously great but not a metabolic boost).

I practice IF because it fits well into my lifestyle and I feel better when my body is in a fasted state. But it is still all about calories in vs calories out. If you want to look into fasting, I suggest leangains.com or Eat, Stop, Eat (I tend to practice more ESE style but also fast for 16-20 hours other days as well).

MorbidMander

In my opinion, from what I have read on this topic on MPF, the term 'fasting' is used in the wrong context. Just because you are skipping a meal does not meal you are fasting. Intermittent fasting = skipping a meal which is not a good idea for any weight loss program. You need to always refuel your body, especially if you are exercising each day and burning calories.

Do yourself a favor and keep to a regular meal plan and keep moving forward.

Um, that's what fasting is. Not eating meals = not eating = fasting. What is your definition of it, exactly? I've done it before, and I'm doing pretty well with my weight loss if I do say so myself. If you do fasts for long periods of time then it messes up your metabolism, but for one day of it? Come on, get real.

As for me, I don't eat for a day when fast. (Yeah, I know unbelievable right, your body CAN go a day without eating). Some people don't like it, some people can't do it. I do it very rarely, maybe like once or twice a month. It isn't going to kill you or hurt you. I've done it before and fasting IS beneficial for your body, it's a proven fact.

ETA: Ah, I didn't read that right, lol. My bad. Cutting calories is not fasting, obviously. Durp. Then I agree on that part.

toddis

I just watched a video series based on it

( http://www.precisionnutrition.com/intermittent-fasting-video-1 )

From their 5th video summary

Fasting might be right for clients with:

a healthy approach to food and eating
experience with nutritional manipulation
a lot of exercise experience
no partner or children; or an extremely supportive partner
a flexible job and lifestyle
low lifestyle stress
a desire for the athletic look

Fasting might not be right for clients who are:

new to diet and exercise
married and/or with children
working in a performance-oriented environment
working in a client-facing job
competing in elite sport/athletics
facing excessive lifestyle stressors
looking to gain lots of muscle or strength


edit to add
( http://www.precisionnutrition.com/intermittent-fasting-video-5 )

Here’s a particularly important piece: There may be crucial sex differences (likely hormonally based) in the response to fasting. Women of reproductive age may have to be more careful about hormonal health — fasting too much, too long, and/or too frequently can disrupt normal hormonal cycles.

CristinaL1983

I just watched a video series based on it

( http://www.precisionnutrition.com/intermittent-fasting-video-1 )

From their 5th video summary

Fasting might be right for clients with:

a healthy approach to food and eating
experience with nutritional manipulation
a lot of exercise experience
no partner or children; or an extremely supportive partner
a flexible job and lifestyle
low lifestyle stress
a desire for the athletic look

Fasting might not be right for clients who are:

new to diet and exercise
married and/or with children
working in a performance-oriented environment
working in a client-facing job
competing in elite sport/athletics
facing excessive lifestyle stressors
looking to gain lots of muscle or strength

I know you are just quoting what it says but I would like to state that I'm a single mom (with a 6 year old), divorced, in school full time and working (I would call that significant lifestyle stressors). And I have had no problems with IF. In fact, with my kind of crazy lifestyle, it works very well for me.

KansasCowgirl

Intermittent fasting is based on the fact that certain hormonal/chemical changes occur in your body when it is in a fasted state.

Exactly when/how long does it take for your body to go into a fasted state? 12 hours? 16 hours? 36hours? How do you know when you just go from hungry to fasting and your body experiences the hormonal changes?

CristinaL1983

Intermittent fasting is based on the fact that certain hormonal/chemical changes occur in your body when it is in a fasted state.

Exactly when/how long does it take for your body to go into a fasted state? 12 hours? 16 hours? 36hours? How do you know when you just go from hungry to fasting and your body experiences the hormonal changes?

It depends on which changes. Your insulin levels drop starting from the moment you stop eating and continue until about 36 hours after you start a fast where they level off (at a low level). Glucogon levels increase by 5 times in the first 15 hours after you start to fast. Growth hormones are released into your blood more often and at levels about 6 x the normal level. Some things were discovered while researchers were looking for something else. The higher stem cell concentration was found while researchers were trying to figure out ways to prevent atrophy in the muscles of the elderly. (They found them after subjects had been fasting for 40 hours and had a muscle biopsy preformed (in 2012).) These things need to be studied in their own research in order to find out exactly how/why/when they happen. Norepinephrine and epinephrine are released into the blood stream increasing fat burning.

As far as when these changes start to happen, a lot of them start right away (as soon as you are done eating) but most continue to either grow exponentially or drop logarithmically over time (generally leveling out around 30-36 hours). So the point of intermittent fasting is to maximize these benefits.

IF has been found to be as effective in increasing life span and decrease heart disease risk as much as those folks who live in a calorie restricted lifestyle (not to diet but for healthy life longevity).

I've read most of these studies (from the sources) myself so I tend to stick with the science as far as when they happen. I've been practicing IF for a while now (several months on purpose before that I accidentally fasted occasionally) so I really rarely even get hungry before about 18 hours. If I, for some reason, wake up starving, I won't fast that day (any more than an overnight fast). But, I usually stick with 16-20 hours/ day and get in a 24 hour fast at least once a week. I feel great, I have more energy when I'm fasting (for a bit I would get bad muscle fatigue but I tweaked my protein intake and it went away) and feel like I get in a better workout.

Hope that answers your questions.