With fasting , you have no calories. From what I understand anyway. So you would go 16 hours fasting , let's say from 9pm till 3pm the next day. During that time there are NO calories. No milk in coffee any thing that goes to and through your lips is calorie free. Then you have your 3 till 9 " feeding" window . What IF does is challenge the idea that you should have 5 - 7 small meals and that your body can only handle a certain amount of protein at a time . It's interesting stuff
The difference is that this is a lifestyle change, ie. you can't just skip breakfast one day and expect to see the benefits.
Take the word 'breakfast' add a space in between it becomes break fast. Modern culture has dictated that this meal is taken shortly after you wake up. Intermittent fasters still have this meal (they have to in order to break the fast) but it is later in the day. The benefits are explained in the video I posted earlier in the thread, have a watch.
Let's be clear about this. This is a different strategy to what was proposed in the BBC's Horizon programme with Michael Mosley. I'm not saying it won't work for you, but it's not the same.
Personally, I'm not sure that "daily fasting" would have the same benefits - although I don't claim to have any expertise here. But I would point out that lots of people do skip breakfast, without it having any significant effect on their weight, or any other proven health benefits.
In contrast, the horizon diet/fasting was leading to very noticeable and measurable health benefits. It's not primarily a weight-loss regime, although that can be a helpful side effect.
No doubt there are many ways in which you can acheive weight loss, but most approaches seem to be about reducing calories, and increasing exercise, which undoubtedly works. The horizon approach isn't specifically about weight loss, but other health benefits (weight loss is a common consequence, probably due to the calorie reduction).
Incidentally, Michael Mosley is now only fasting 1 day in 7, because he was losing too much weight, but still believes it will have the same health benefits.
I doubt it matters hugely which version you use, all seem to be documented online. Let's not forget that Michael Mosley on his 5:2 or 6:1 fast is still consuming 600 calories on his fasted days.
The programme also promoted the 'eat as much as you like on non-fasted days' and were filming at a burger joint. To anybody taking the programme at face value this says fast for 48 hours and stuff your face with McDonalds for 5 days. Whilst this person might see the health benefits mentioned its certainly not something I would want to do.
I was more intrigued by 'fat loss' rather than 'weight loss'. This seems to be something that has been adopted by body builders (leangains.com) with great success. For me, IF is purely experimental at this stage and I will say, I don't believe I've lost any weight so far. However, I do have a better relationship with food as a result of this. I anticipate that the real results will only start to show when I begin to regularly train whilst fasting (and by that I mean 3 cardio sessions a week at least 70% maximal heart rate).
I do think it makes a difference. Going 14 hours without food is something that I do regularly when I'm not fasting, by skipping breakfast, and I don't think this has any effect on my weight or health. I don't think it matters what time you eat your meals in a 24 hour period - your body simply adjusts to your daily eating patterns. Some people graze, and others never snack - I don't think it has an effect either way, it's the amount of calories consumed that matters.
In contrast, fasting for 24 hours (or more) does have an effect. Your body reacts metabolically - or at least that is the suggestion by the programme.
I don't think the programme was promoting bingeing or unhealthy diets on your days off. It was simply illustrating that the choice of food was less significant than we might imagine. If you regularly eat at macdonalds (whilst maintaining a healthy balanced diet), then there is no harm in continuing to do that. The message was carry on as normal on your days off. But if you are an obese person, then you you need to address that anyway. The fasting may be helpful in reducing your weekly calorie intake. But you still need to consume the recommended nutritional levels. But most of us are consuming too many calories in the West. Fasting will help you reduce your weekly calorie level by about 10-20%. Following nutritional guidelines is still very important for health - fasting doesn't solve that. In fact, it may even reduce your intake of healthy nutrients. So perhaps you should be considering eating more apple peel on your days off, rather than macdonalds. I think that's what the documentary was saying.
On the issue of body building - I think that's a different issue entirely too. And the documentary wasn't saying anything about what you should do for that. I strongly suspect that body building (and their associated diets) are probably counter productive to the health benefits being pursued by documentary - but it's not a subject I know much about.
But that is my point. Most people who regularly skip breakfast do not psychologically have an 8 hour window in which to eat. So whilst they may not eat until noon/1pm they will most likely consume more calories than somebody who follows daily IF fasting, which is essentially a calorie restricted lifestyle.
There are a lot of studies which illustrate this relationship between skipping breakfast and being overweight, such as this one- Skip Breakfast, Get Fat
I think the message in the programme was supposed to be that on non-fasting days you can eat whatever you like, not how much you like (as in any kinds of food up to your usual calorie intake). However, the use of burgers and junk food wasn't helpful to most viewers who could easily misunderstand this.
As for the metabolic effects, it is very difficult to measure without getting us all in a lab and it will certainly vary from person to person. I believe (from what I have read) that autophagy increases with fasting with the real benefits kicking in at around 16 hours and further increasing to a point of diminishing return. Therefore by fasting a minimum of 18 hours/day I should see some benefits.
The link between weight training or better still, resistance training (let's not call it body building as that perhaps conjures up the wrong image) is linked to metabolism. Lean muscle mass (or reduced body fat) results in a better metabolic rate. Ie. sat still your body is more efficient at metabolising calories.
The full circle is that by using IF, growth hormone is stimulated making it theoretically easier to build muscle (or lean mass) and therefore improve metabolism. Fasting enhances growth hormone secretion and amplifies the complex rhythms of growth hormone secretion in man.
Perhaps the most interesting article is the British Medical Journal review of the Horizon programme. It discussed several pieces of research which were omitted and summarise 'Any attempt to encourage reduced calorie intake in a nation with such high rates of obesity as our own may be commendable, but critics will likely find little new in the advice Mosley dishes out: reduce your calorie intake, reduce your weight, reduce your cardiovascular risk factors. Perhaps thats the message to hope people take forward from this'.
Here's the link- BMJ Group blogs: BMJ » Blog Archive » Emma Rourke reviews Horizon: Eat, Fast, and Live Longer
Therefore IF is nothing more than a tool in which to manage calorie restriction; which may, or may not come with associated long term health benefits (reduced risk of cancer, heart disease, diabeties etc etc...). Until someone conducts a longitudinal study in humans we will never really know.
I agree that calorie reduction is the key to weight loss, and exercise can help too. And I tend to agree with the points in the BMJ view about the programme. A lot of this is untested, and long-term studies are needed, as you (and the BBC) pointed out.
But I don't agree with the conclusions in the WebMD article, at all. That seems like quite pseudo-science, to me. Scientists may well have noticed that we are less likely to crave high calorie foods, if we've eaten 90 minutes beforehand - that seems like a "no **** einstein" observation data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 I don't think that necessarily means that we consume high calorie food because we skip breakfast. I tend to eat a light lunch, myself. Otherwise I tend to feel lethargic in the afternoon. In fact, I've never met anyone significantly overweight who regularly skipped breakfast, but there probably are some.
I still think that the health benefits discussed in the horizon programme arose from fasting over more than 24 hours, and that this was key. And there was some science to back up those claims. But there may be other ways to acheive the same effect. I do think the programme was suggesting more than just calorie reduction and it's relationship to weight loss (or fat loss).
A lot of it is simply down to the convenience aspect, not any deep-rooted psychological craving for high-calorie food. For example, at home you may take the time to make a bowl of porridge and some chopped fruit - it will fill you up until lunchtime and will only be ~300 calories. On the other hand, say you miss breakfast because you're in a rush, so you stop to buy a muffin and a latte - you could be consuming ~600 calories and additionally won't feel as filled up as you would have from the porridge. It's not that skipping breakfast causes us to crave high-calorie foods, but rather that the quick option convenience foods we consume to fill the gap tend to be high in calories and don't fill us up as much, therefore we're more likely to consume excessive calories.
Week 1 results - doing daily 18 hour fast, 6 hour feed.
Lost 2 pounds,
Lost 4cm off waist (other measurements remain the same)
Body Fat reduced from 23.3% to 21.2%
Will be carrying on this week but now introducing exercise. This will consist of 2 boxing training sessions (1 hour per session) at my local club (bag work, skipping, lots of sit ups (with and without 3kg medicine ball), push ups, squats, shadow boxing- ie. beginners stuff) and 2 x 4 mile runs.
How is everyone else doing?
Well, the article suggests that it increases cravings, and I can believe that. So there may be more to it than the convenience factor. My point is not about what the scientists discovered, but the article's conclusions - that skipping breakfast causes fatness. It not the skipping breakfast that causes fatness, it's the calorie intake if you cannot control your cravings. The title should had been "skip breakfast, get cravings", not "skip breakfast, get fat". They are muddling cause and effect for a good headline, I think.