The FastDay Forum

I have found a few references that imply that you need to fast for a minimum of 16 hours which is possibly what 16:8 is based on. Below are a few excerpts from one site

"To be effective, in the case of daily intermittent fasting, the length of your fast must be at least 16 hours....This is because it takes about six to eight hours for your body to metabolize your glycogen stores; after that you start to shift to burning fat. However, if you are replenishing your glycogen by eating every eight hours (or sooner), you make it far more difficult for your body to use your fat stores as fuel". http://fitness.mercola.com/sites/fitnes ... efits.aspx

However, I think that when it comes to losing weight your energy intake has to be less than your energy output whether you are doing 5:2, 16:8, counting calories, WW, SW or any other diet. For me, the whole point of doing 5:2 is for the health benefits and weight loss has been a bonus.

Every body is different, and whether a body starts burning fat in 16, 24 or more hours depends not only on the body, but also on the content and quantity of food eaten in the 'last' meal.

Most people here are here to lose weight. The only way to do that is to consume fewer calories than a body needs to operate. Even if you do burn some fat by not eating for 16 hours (doubtful for most people), you can easily negate that fat burn by eating more calories than your body needs to operate that day (whatever fat that was burned is replaced by fat from the excess calories eaten in the 8 hour period). In addition, eating a lot of calories in a short time (there is another book out there that says you should eat all of your calories in one meal, thus 24/1) causes a blood sugar spike that almost insures fat building.

I say again, if eating all of your daily allowance of calories needed to maintain or lose weight in an 8 hour period helps a person, go for it. But you can accomplish the same result by eating that same daily allowance in 24 hours. The time frame is irrelevant.

One last thing I thought I'd add that was brought to my attention last night: Although the studies were done on mice, Salk researcher Panda says: "The good news, he adds, is that most successful human lifestyle interventions were first tested in mice, so he and his team are hopeful their findings will follow suit. If a time-restricted eating schedule can prevent weight gain by 10 to 20 percent, it will be a simple and effective lifestyle intervention to contain the obesity epidemic."

I might also add, and honestly, I'm not stirring the pot, but I realized that Dr. Mosley's Fast Diet was just an experiment he did on himself without any studies. The real studies were done on Alternate Day Fasting and The 2 Day Diet which are different although similar.

So as far as studies go, in the end I take them with a grain of salt. I'd never have researched this on my own. We just have to find what works for us.

simcoeluv,

Without wishing to get into a debate about this have you actually read anything about 16:8?
Most of the people considering this here including TML who started this thread are close to their targets and are below a BMI of 25, they are looking to tweak their already succesful Fasting WOL

simcoeluv,

Without wishing to get into a debate about this have you actually read anything about 16:8?
Most of the people considering this here including TML who started this thread are close to their targets and are below a BMI of 25, they are looking to tweak their already succesful Fasting WOL

I have read most of the book and researched on the internet.

I have also had a discussion with a research scientist doing research on weight loss/dieting/timing.

It is really simple - to lose weight, you have to eat less than you consume. There are no studies anywhere that show that if your real TDEE is, say, 2000, and you eat 2000, or more, but at a certain time of day you will lose weight. Same with weight maintenance. If your TDEE is 2000, and you eat more than 2000 on average, it makes no difference when you over eat (in an 8 hour period or otherwise), you will gain weight. How fast and how much depends on how much you overeat.

If someone goes on 16:8 and loses weight, they are eating below their TDEE. If someone goes on 16:8 and maintains their current weight, they are eating at their TDEE level. If someone goes on 16:8 and gains weight, they are eating more than their TDEE. Note you cannot argue that calorie intake does not count if you are losing, but does count if you are gaining. If you are eating 3000 cal. in 8 hours and gaining a pound a month, can you really argue you would be gaining a pound and a half a month but for eating 3000 cal. in an 8 hour period?

It is that simple.

My signature says it all. When you eat is not a factor in weight loss. I'm done.

Excellent I am glad you are so well informed
I bow to your superior intellect.

Having reached my goal (then reset my goal) weight I have now moved to an 8 hour eating window, and fasting one day a week.

[carorees]

OK, so my opinion is that for weightloss, it is self evident that you have to eat less calories than you burn, but if your insulin levels are constantly high due to spreading out your eating it will be hard to shift fat as lipolysis cannot occur while insulin is high. So you will likely burn some protein to provide the missing calories instead. This is why on a standard calorie restriction diet fat and muscle are lost. By contrast, intermittent fasting or low carbohydrate allows insulin levels to fall so that fat burning can occur. Reducing calories by fasting results in more fat loss than reducing calories in a standard diet.

Whether 16 hours is a long enough fast to allow fat burning will depend on many things including the food eaten during the 8 hour window. So, like everything else, you have to experiment to see if it will work for you.

For me, being careful with carbs and skipping breakfast to allow a 16+ hour fast results in about 1kg loss per week at the moment, which is great as I had been doing 5:2 for 36 weeks before experimenting with 16:8 and my weightloss had slowed to around 0.5 kg/week.

For me, being careful with carbs and skipping breakfast to allow a 16+ hour fast results in about 1kg loss per week at the moment, which is great as I had been doing 5:2 for 36 weeks before experimenting with 16:8 and my weightloss had slowed to around 0.5 kg/week.

Same for me Caroline. Its kicked me out of a very long stall.

OK, so my opinion is that for weightloss, it is self evident that you have to eat less calories than you burn, but if your insulin levels are constantly high due to spreading out your eating it will be hard to shift fat as lipolysis cannot occur while insulin is high. So you will likely burn some protein to provide the missing calories instead. This is why on a standard calorie restriction diet fat and muscle are lost. By contrast, intermittent fasting or low carbohydrate allows insulin levels to fall so that fat burning can occur. Reducing calories by fasting results in more fat loss than reducing calories in a standard diet.

Whether 16 hours is a long enough fast to allow fat burning will depend on many things including the food eaten during the 8 hour window. So, like everything else, you have to experiment to see if it will work for you.

For me, being careful with carbs and skipping breakfast to allow a 16+ hour fast results in about 1kg loss per week at the moment, which is great as I had been doing 5:2 for 36 weeks before experimenting with 16:8 and my weightloss had slowed to around 0.5 kg/week.

I agree with everything you have said.

'being careful with carbs' is also interesting for those not familiar with the practical effects of a low carb diet (not in body chemistry effects).

I was one of hundreds of 'lab rats' for a 2 1/2 year clinical study comparing the low fat to low carb diets. I lost 35 pounds in 3 months on the low carb plan. I could eat any and all fat/protein I wanted, as long as I kept my carb intake to less than 20g per day. (Think of Atkins induction phase.)

Most people would assume I was eating a lot of calories and still losing weight. They would be wrong. We had to keep food diaries of every bit of food/drink we consumed (got tiring after 2 1/2 years). When I went back to those diaries I kept during my rapid weight loss phase and computed calories instead of carbs, I found I was eating around a 1000-1200 cal. per day diet. As I could eat all I wanted of anything that did not contain carbs, it was impossible to get hungry - and I never was. But I was not hungry because of the nature of the food I was eating - it digested slowly and provided my bloodstream with a constant flow of blood sugar. Basically, I lost weight because I was eating fewer calories (the only way to lose!). As an aside, when I compared my weight loss with my TDEE and caloric intake, I was within 1 pound of where the 'math' said I should have ended up. We all know a pound is a rounding error.

I think many posters on the Forum have discovered this when for fast days they recommend eating more protein/fat/complex carbs so you won't feel so hungry.

Basically, if you eat fewer carbs and more fat, most people will actually eat fewer calories and lose or maintain their weight better. And I know there are exceptions, but exceptions are not the rule.

Thank you for the post!

As some may well know I am another living breathing example on this forum of making a choice 12 weeks ago to 5:2+ 16:8 x3 weekly Loved 5:2 but hit a plateau. The other issue was that liking the boundaries of 5:2, I felt all at sea on non fasting days so the idea of a time restriction 3 days a week and yet unrestricted eating I could do.

The proof is in the pudding for me albeit I am not so much a pudding anymore with 12kg lost. So my plan has been for 12 weeks 5:2 fasting and 3 /4 days a week 16:8 to adhere to the 8 window plan and only really get to fit in 1 day of gay abandon. But I have another up my sleeve

Case in point yesterday I ate freely from dawn to bedtime and chocolate was involved and apple pie double cream and baked potato and with some cream frais. Today is a 5:2 liquid fasting day and having had a bumper feeding day yesterday I am very keen to fast today. I now liquid fast on my 5:2 days as my fasting TDEE is 400 cals and I tuck into about 3 soups from this site and teas and coffee and water.

It is not difficult. My twin in this is @Wendy Darling

Just to say that I don't understand the clever stuff nor the science behind all this but I do love 5:2 I just fell into 16:8 naturally on the other 3 weekdays and I do limit my intake to healthy meals and no bread, potatoes, pasta, rice, chocolate nor alcohol on all of those days.

Fridays I go a bit over, well, it is Friday and there is always chocolate and wine involved Saturdays and Sundays I still tend to stick to 16:8 but maybe have the T word shhhhh and some roast potatoes.

I am losing really slowly but that doesn't bother me, my clothes are looser and I just love being more mindful about what I am eating. A least I can now make informed choices.

Have a look at my signature, it says it all. I am happy and nothing will change my mind.

I just hope that my twin @gillymary and I are not wandering off on our own in the wrong direction looking at our watches and swishing our oil

You are not on your own, I'm with you all the 16/8 way

Ballerina x

Our inspiration of course is Ballerina

What was that @Wendy darling

oh damn now I have drooled coconut oil all down the front of my size 12 top.
Note to self "don't talk with my mouth full of coconut oil" she said as she slipped away

Wow TML look what you've missed (she's probably out festivalling and feasting and won't see this until tomorrow afternoon at the earliest!)

He he he I'm here!
The show was amazing! Two and half hours of music inspired from musicals, it was fab!
So, after having a late lunch of 150 calories I had a very nice dinner and two beers a while after midnight. 17:7 for me today, easily.

So, on the 3rd of September I'm leaving for a weekly business trip. I will include lots of pleasure because I will be staying at a very nice resort with A SPA!!! I have full board&drinks and I am waiting to see the meal times in case I can do 16:8 or at least 14:10. I won't worry about it though.

Until then (that's 11 days including today) I am planning to do 16:8, plus 5:2 (I'll try to fast 4 times), plus 2 days of attack.

When I come back, I will resume my usual 3:2:2 plus 16:8. I am hoping that I won't gain more than 2 kilos. Luckily, I am one of those weirdo's who eat less at buffets compared to a la carte so I'm probably lucky.

Hi TML, I have being doing the 16:8 thing for quite some time now and am still losing weight consistently. I always have one, two or sometimes three cups of tea with milk in the morning before 12.
I love 16:8 because it works for me without any feeling of being deprived of the foods I love.