Intermittent fasting for active people?

Eric Carlos wrote:

You should have stopped there.  The metabolic increase do to the thermic effect of food is consistent for 1 meal or 5 meals.  However insulin resistance is not caused by a slow metabolism: a slow metabolism is more of a sign of insulin resistance.  Also, there is only one "fat storing" hormone - Insulin.  Limiting an insulin response has been proven to reduce the ability to store fat.  

Insulin is also one of the most anabolic hormones, can facilitate blood sugar and lactate transport, drives down cortisol (a fat storage hormone itself), and assists in a whole heap of other beneficial processes. Even Berkhan disproved the idea that calories being equal higher insulin means more fat storage as long as protein levels are kept in check and the person isn't drip feeding glucose.  Creating and storing fat is a costly process that depends mostly on total calories in vs whatever sum of various thermic and activity factors to create a denominator that is or is not favorable to fat loss. There are not magic tricks, however, by maintaining decent protein intake and healthy fat intake, carbs are naturally going to be limited to much lower amounts than most sedentary people take in. Your brain and metabolic processes will use far more glucose than fat cells will to expand unless there is an excess of calories.

I SORT of do this. I'm a little obsessive, and weigh myself every day with scales that also (roughly) measure body fat.  If I feel I'm getting over my target weight, or if I want to be especially light, I just go without tea (dinner, supper whatever you call it   ).  This means I don't have anything to eat from about two in the afternoon till about ten the next day (although, TBH, there are calories there as I do have a beeriyay or two  every single day).  I find this allows me to lose a kilo or more.  Also, I often climb in the morning on weekends on an empty stomach, esp if it's more endurance stuff (i.e. laps of a climb on top rope) as I feel I can use the fat that's on me for energy rather than having breakfast.

I know this isn't strictly intermittent fasting but it does work for me in managing my weight.  Incidentally, often I can go for up to five days at pretty much the same weight and BF (to one decimal point i.e. 62.8 and 11.9%).

the schmuck wrote:

Those of you that do 24hr fasts, what does that look like?  I assume that you essentially eat one meal per day, and nothing but water for the remainder. How many calories do you take in?  Do you ever break the fast, or is it an everyday pattern? When do you consume your single meal? 

I don’t do a 24 hour every day, maybe every 3rd day or so. Basically you eat a normal dinner until you feel full, then don’t eat again until the next night at the same time. During that time you can drink water, sparkling water, tea, or coffee. If I start feeling hungry I drink some water or tea, normally it goes away within 10 minutes or so. It hasn’t happened to me, but the caveat most people put out there is that if you start feeling weak or dizzy you should stop the fast by eating something and drinking plenty of water. When you do eat, you eat a normal healthy dinner until you’re full. 

On the days I don’t do a 24 hour fast I do a 16 hour fast. I skip breakfast and don’t eat until lunch. 

Serious question. If you fast for 16 hours, when do you eat?  And if you break your fast with just some fruit, is there room to eat anything else on such a schedule?  

I tried something that was not quite this restrictive for about 8 months, and although I lost a fair bit of weight and actually got relatively stronger, I also developed some health issues that forced me to stop. 

So, I was fasting between 7am and 9pm, but would supplement in the middle of the day with electrolytes, lots of water and one small scoop of protein powder and dietary fiber. I would eat before going to work, and again after returning from the gym or evening run. Did this every day. According to urologist, this was most likely the cause of my kidney stones, which was the worst experience ever. 

the schmuck wrote: So, I was fasting between 7am and 9pm, but would supplement in the middle of the day with electrolytes, lots of water and one small scoop of protein powder and dietary fiber. I would eat before going to work, and again after returning from the gym or evening run. Did this every day. According to urologist, this was most likely the cause of my kidney stones, which was the worst experience ever. 

no idea if fasting was the cause of a stone.

but you are breaking the fast with protein power and fiber.  you don't need the supplementation.

I’m sure that it was the supplements and not the fasting, and yes, it was the whey and the electros. Initially I had a really rough time going for 12 to 14 hours during the day without taking anything in, so I started the above. However it sounds like some of you factor your sleep into the fasting interval, which would make it a little more manageable. 

Yeah dude certainly use your sleep (which hopefully is at least 7 hours preferably more) as part of the fast. I do similar to what others mentioned I stop eating at 8pm and wait until at least noon but usually later most days. I don't know enough about kidney stones but I would bet against the fasting being a contributing factor. If it's hard for you to fast and it's something you're interested in, start with 12 hours and work up from there. 

Definitely use sleep to start the fast. Makes it quite easy. Skip breakfast, eat a later lunch and 18 hours is easy to hit.

I've done a combo of IF and the 5:2 - I'll try and eat less on the days I fast. You don't need much to feel full - so I'd just eat a half sandwich vs my regular one. Normal dinner. Do that a couple days a week and I lost 10-15+ lbs easily.
If you want to magnify the fat loss, look into a simple Tabata/HIIT workout too. 4min a day and it got me down a couple more pounds, definitely leaner and easy to maintain.

On our climbing trips I go back to "normal" eating. I like my morning breakfast sandwich and coffee (+ usually some chocolate/cookies/etc) at the campsite too much to skip that routine.

I've never been one to diet and found this easy to stick to. Got a happy hour gathering / eating out / etc coming up? Skip bfast that day, eat a light lunch - then engorge as I normally would. Overall I'm taking in less calories than I would have in the past, but not missing out on "enjoyable/social" eating (which we don't do often).
(I don't do IF daily - I like my breakfast sandwiches too much. I don't cut sugars, grains, etc - I like those too much)

I call it the "I'd rather not eat, than eat healthy diet" - b/c for me, its easy to cut out a meal and calories, than to change the fundamental makeup of what I eat. The are studies to see whether IF has benefits at the cellular level, etc, also. Supposedly there may be benefits beyond just being a healthier weight, but I'd like to see more data on it. 

I"ve been doing it for a year, 14 hour minimum fast daily, no cheat days.  I'm 38yo, 5'9", 140 lbs. and pretty slender so I didn't lose any weight.  My cholesterol numbers did not change after my last blood panel and my other numbers are normal, so there have been no other results I can speak of from a scientific perspective.  I've experienced a few of benefits which is why I kept going with this:

1. I have more energy and don't crash as often as before.
2. My recovery time is faster after workouts.  A boulder session would leave my fingers wrecked for a few days previously, but now I'm ready to go again next day.
3. My poops are heavenly.
4. I sleep better.

During my climbs, both on long multipitch days and intense bouldering sessions, I have not noticed any drop in energy despite not eating any breakfast.  

If you're looking to lose weight, a couple of my friends started on it for a couple of months and lost 15 pounds each, both starting at normal body weights.  One of them had to stop because she continued to lose weight on it, so she now intermittently intermittent fasts.  

Matt N wrote: Definitely use sleep to start the fast. Makes it quite easy. Skip breakfast, eat a later lunch and 18 hours is easy to hit.

I've done a combo of IF and the 5:2 - I'll try and eat less on the days I fast. You don't need much to feel full - so I'd just eat a half sandwich vs my regular one. Normal dinner. Do that a couple days a week and I lost 10-15+ lbs easily.
If you want to magnify the fat loss, look into a simple Tabata/HIIT workout too. 4min a day and it got me down a couple more pounds, definitely leaner and easy to maintain.

On our climbing trips I go back to "normal" eating. I like my morning breakfast sandwich and coffee (+ usually some chocolate/cookies/etc) at the campsite too much to skip that routine.

I've never been one to diet and found this easy to stick to. Got a happy hour gathering / eating out / etc coming up? Skip bfast that day, eat a light lunch - then engorge as I normally would. Overall I'm taking in less calories than I would have in the past, but not missing out on "enjoyable/social" eating (which we don't do often).
(I don't do IF daily - I like my breakfast sandwiches too much. I don't cut sugars, grains, etc - I like those too much)

I call it the "I'd rather not eat, than eat healthy diet" - b/c for me, its easy to cut out a meal and calories, than to change the fundamental makeup of what I eat. The are studies to see whether IF has benefits at the cellular level, etc, also. Supposedly there may be benefits beyond just being a healthier weight, but I'd like to see more data on it. 

The good old fashioned calories in < calories out.

Karl Walters wrote:

The good old fashioned calories in < calories out.

that is/was a flawed premise to begin with.  the biological response to 100 cals of sugar vs 100 cals of olive oil vs 100 cals of steak  is dramatically different.  

How is that a flawed premise? If you eat less than you burn you will lose weight. If you take in more than you burn you gain weight. Sure 100 calories of sugar is used differently in the body than 100 calories of fat but it's still 100 calories.

Mike Collins wrote: How is that a flawed premise? If you eat less than you burn you will lose weight. If you take in more than you burn you gain weight. Sure 100 calories of sugar is used differently in the body than 100 calories of fat but it's still 100 calories.

rather than typing multiple paragraphs...

I have found intermittent fasting to be very helpful.  I am healthier and am able to easily maintain a leaner body and recover faster, when intermittent fasting.  

If you don't have have any excess body fat and have trouble eating enough already, then fasting probably is not beneficial.  Intermittent fasting is much easier if you avoid spiking your insulin (e.g., high glycemic loads) and become well adapted to metabolizing fat.  If I do eat high glycemic foods, I eat them after excersizing, when my glycogen stores are already depleted.  When I am well fat adapted and have excess stored fat, I don't get hungry and can just eat whenever is convenient for me.  A low carbohydrate diet paired with intermittent fasting works best for me.  

What many people do not realize is that insulin not only acts to transport glucose, it also inhibits the release of fat from your adipose tissue.  So, if you are constantly eating carbohydrates and keeping your insulin level high, you will not be able to get much energy from stored fat.  

I'm not claiming to know the all the answers and I agree I do feel great with IF I have been doing it for over two years now. I knew the Dr Fung post was coming. I certainly do agree with a lot of what he says but where I disagree (I'm not a doctor, but am very interested in this topic and have done some research) is that saying sugar is much more fattening than other energy sources. I think it is way easier to overeat say pasta or chocolate pretzels than say a steak but at the end of the day 100 calories will equal 100 calories. Are you going to feel like shit if you eat only sugar? Probably. But if you eat 2000 calories and burn 2500 you will still lose weight. If something is working for you to maintain a healthy weight keep doing it. That's the important thing. 

Mike Collins wrote: I'm not claiming to know the all the answers and I agree I do feel great with IF I have been doing it for over two years now. I knew the Dr Fung post was coming. I certainly do agree with a lot of what he says but where I disagree (I'm not a doctor, but am very interested in this topic and have done some research) is that saying sugar is much more fattening than other energy sources. I think it is way easier to overeat say pasta or chocolate pretzels than say a steak but at the end of the day 100 calories will equal 100 calories. Are you going to feel like shit if you eat only sugar? Probably. But if you eat 2000 calories and burn 2500 you will still lose weight. If something is working for you to maintain a healthy weight keep doing it. That's the important thing. 

It has to do with the glycemic index. Sugar makes the calories available too fast for the body to use, so it stores the extra energy as fat. This then makes the energy not readily available for use which then in turn slows down the metabolism more as the body now has to get by on fewer calories (unless more food is eaten). Doing this over time will eventually result in a lot of weight gain and slow ones metabolism, resulting in the hard to lose weight gains which plague many Americans.

Hunger symptoms come and go. Most of the time you don't feel it, if you're occupied with a task that outweighs succumbing to your symptoms. If you're always hungry and feel like you need to eat when you're hungry, this is what causes the mental and physical disease of obesity--you're bored with your meaningless, daily habits, and shoving bad choices down that gullet is a form of a drug that you use to chase your high to stay nice and comfortable. Or, start implementing tiny, easy methods, turn them into habits, see how your symptoms and your motivations and perspectives change (cough!) For the better!

Physical training before first morning light in active duty military for almost 6 years was once a way of life for me. Everyone's feet hit the deck, shit, shave, don PT uniform and go form up! The chow hall wasn't open yet. PT for about half an hour, or whenever the NCO secured PT. Then shower, eat, go to work. I always felt like a million bucks for the rest of the day on the days we did this! People that haven't experienced this for a lengthy period will never see a pattern if you don't set your own bar higher! Like, now!

I don't want people to think I am anti IF because I do it every day. I am just super interested in the subject and I am not saying anyone is right or wrong these are all just my opinions. For people interested in the subject these studies may be of interest (these are free articles I believe just copy the title into google and it should come up). If insulin caused fat gain, so would eating protein because that has also been shown to cause a spike in insulin. Just my opinion based on what I have read. Take it or leave it. Do what works for you!

An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods.

Effect of skipping breakfast for 6 days on energy metabolism and diurnal rhythm of blood glucose in young healthy Japanese males.

The acute effects of four protein meals on insulin, glucose, appetite and energy intake in lean men.

Mike Collins wrote: I don't want people to think I am anti IF because I do it every day. I am just super interested in the subject and I am not saying anyone is right or wrong these are all just my opinions. For people interested in the subject these studies may be of interest (these are free articles I believe just copy the title into google and it should come up). If insulin caused fat gain, so would eating protein because that has also been shown to cause a spike in insulin. Just my opinion based on what I have read. Take it or leave it. Do what works for you!

An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods.

Effect of skipping breakfast for 6 days on energy metabolism and diurnal rhythm of blood glucose in young healthy Japanese males.

The acute effects of four protein meals on insulin, glucose, appetite and energy intake in lean men.

Both steak and sugar may cause an insulin spike, but they have different glycemic indexes and they are comprised of chemically different substances. As a result, I would expect them to interact with the body in different ways.