The FastDay Forum

Hi all

I have recently been sent on a link to this article,
I notice it's from January so apologies if this topic is posted elsewhere:
The heading is fairly sensational - implying that women may develop diabetes as a direct result of the diet but it refers to an IF clinical trial in 2005, saying
"At the end of the trial there was no insulin improvements in the women and their glucose response got worse, while the men had no glucose changes and their insulin response improved."

Apparently negative effects are worse for younger women and those who do not have too much weight to lose, while overweight women as well as women over the age 50 seemed to enjoy the benefits of fasting.
here is the link:
http://www.express.co.uk/life-style/hea ... n-diabetic

I would really appreciate your thoughts on this- I'm not sure if there are any ongoing studies but the idea that there could be negative implications for women on 5:2 only would be very unfair if true!
It also talks about negative impact on fertility.
All this is very scary, and I don't really want to believe it as I am really enjoying 5:2 and have a lot of hope for it. Obviously though, if these are real effects there is no way I want to compromise general health and fertility.
Please do let me know if you have had any related experiences or know of any further trials.

Caoimh , I read this yesterday.
http://ifasters.com/intermittent-fastin ... -in-women/
Barbara

Thanks so much for this Barbara. I am really pleased and relieved to see it .
I had noted that the negative results were seen in tests on rats, not humans so it is a relief that human fertility seems unaffected by fasting, or even improved (Poor rats though).
Hope someone has good news about the risks of diabetes too!

Hi Caoimh , I am no doctor but surely by lessening the amount of insulain floating around in our bodies by not eating regularly and therefore spiking it must surely be a better bet than 'grazing' all the time.
Also this is why a lot of us have ditched the carbs , they spike the blood sugars,I was amazed to find that a slice of whole meal toast has more speedy affect on blood sugars than a tablespoon of sugar.
Fat and( protein up to a point) are the only things that dont spike blood sugars.
Barbara

Hmm, I was sure we had debunked this study but I can't remember it so perhaps it was in one of the facebook groups before we got the forum set up. There are so many holes in it, it's hard to know where to start.

Their greater muscle mass also protects men from some of the downsides of the diet. Dr Collins explains: “The average adult turns over 300grams of protein a day.

Eighty per cent of that is recycled, broken down and reused; a bit like Lego bricks, but after a certain period of time these proteins become worn out and are lost to the body.

“What we cannot salvage, we need to replace and once you start skipping meals you will compromise your intake.

“Protein is non-negotiable, and unlike other micronutrients you need it every day, but men have a higher reserve of muscle they can call on for protein during fasting days.”

The protein requirements are only around 46g/day for a woman, 56g/day for a man. On my fast days I am usually having around 40-50g protein anyway so no problem there. Even if you did not eat any high protein foods such as meat/dairy etc, one day without protein would hardly cause your body to fall apart. And in any case, most people in the developed world are overeating protein and this is a factor behind many cancers. Reducing protein to under 60g per day is recommended to lower IGF1 and so cancer risk. When the body is not getting new protein it uses the old worn out cells for spare parts (autophagy) which destroys cells that might turn into cancer cells. So, all that concern about protein intake is bunkum.

The danger was identified in a 2005 study published in Obesity Research which tracked eight men and eight women as they tried intermittent fasting for three weeks. All were a healthy weight or carrying only a few extra pounds, with BMIs between 20 and 30.

At the end of the trial there was no insulin improvements in the women and their glucose response got worse, while the men had no glucose changes and their insulin response improved.

Several problems here. First they were looking at normal weight people whereas most of the people on the forum are looking to lose weight. As insulin resistance is highly associated with overweight and reducing weight improves glucose tolerance, this is a good thing. Fasting also improves glucose tolerance in people with insulin resistance because during fasting insulin levels are lowered.
However, what about when we reach our target weight I hear you ask? Well, another problem with the study mentioned is that if you look at what happens in the body when given glucose following a fast you do get higher blood glucose levels and lower insulin levels than you would like but that is because the high levels of circulating fatty acids that were being used to supply energy during the fast inhibit the action of insulin (because you don't want to store any incoming glucose as fat when you first start to eat after a fast, you need it to be turned into glycogen). However, after a short time, everything goes back to normal. If the researchers had waited for another day of normal eating they would have got different results. Also, the subjects in this study had a complete 36 hour fast every other day which is very different from a very low calorie day twice a week which is what we are doing in 5:2. I really don't think this is an issue because anyone with normal body weight is not going to be doing alternate day fasting unless they want to disappear completely!

In part, this may be due to differences in the way we store fat. Women are most likely to be pear-shaped and pile extra pounds on to their hips while men become apple-shaped and gain weight around their middle, which is much more dangerous and increases the odds of developing diabetes and heart disease.

Dr Collins says: “You would expect men to benefit more because the natural distribution of their body fat predisposes them to metabolic syndrome [a precursor to diabetes]. Losing weight around the middle will increase insulin sensitivity, and reduce their risk.”

This dangerous apple-shape becomes more common in women after menopause, which suggests there may be some benefits to the 5:2 regime for those over 50. However, for younger women there are serious concerns about fasting and fertility.

I think you only have to look around to see that these days most women are apple shaped whatever their age. Even women who are pear shaped have excess fat around the middle too. (I don't know why this has changed over the years. I have my suspicions about certain types of fats appearing in ready made foods but no proof). But the evidence all around us shows that few women doing 5:2 will be 'at risk' from 5:2. Rather most of us are at risk if we don't take some kind of action over our weight.

Studies at the American National Institute on Ageing found that when rats are put on a restricted diet the females stop ovulating and their ovaries shrink.

Being overweight reduces fertility too. You have to go very low in weight before it affects fertility.

Eating disorders are rooted in psychological problems, but she says fasting encourages “disordered eating” and that could tip at-risk dieters into a full-blown eating disorder. “Fasting creates a feeling of euphoria because blood sugar is running quite moderately and that can be addictive. It is very important that you don’t do more than two days a week,” she says.

What on earth does "blood sugar is running quite moderately" actually mean? Anyway, it seems to me that the major issue in today's world is not anorexia but obesity. It is highly unlikely that someone who has struggled with overeating for years is going to tip into anorexic behaviour.

The warning is borne out by research at Columbia University which found changes in female brain chemistry are directly related to food intake; the greater the hunger, the bigger the impact.

As we all know by now, after fasting our hunger is reduced not increased.

In female rats, even a modest cut in calories triggers a sharp increase in corticosterone levels and encourages the body to lay down fat stores, according to studies at the National Institute of Ageing.

Fasting results in low insulin levels which actually prevents fat from being laid down but rather fat is mobilized. Increases in corticosterone levels do not occur with fasting until a couple of days into the fast. Again we are only fasting for 1 day at at time. The sentence quoted would be more suitable to be used to explain why normal calorie restriction dieting results in fat gain.

Dr Collins says, “We have to get away from this idea that the 5:2 diet is a panacea, an optimum diet. It isn’t.

No, I don't think we are claiming it is an optimum diet. What we are claiming is that, in a situation where we are faced with massive food availability particularly of foods that our bodies have not evolved to deal with and which are highly desirable because of their sugar and fat content, this diet allows us to compensate for some of the undesirable consequences of over nutrition while enabling us to continue to eat the foods we like. Of course it won't suit everyone, but no diet will do.

Oddly, the studies that do give some cause for concern about fasting and lowering IGF1 are not mentioned! These relate to low IGF1 and development of frailty and to fasting and heart muscle problems. Elderly frail people often have low IGF1 but whether that is because these folks have reduced their calorie intake or whether the low IGF1 develops in age anyway is not clear. Presumably when any of us reach a great age and are getting too thin we would stop fasting. The relationship between fasting and heart muscle problems are to do with high circulating fatty acids (that you get when burning fat for fuel) and are seen with chronic ADF in rats. As we are not alternate day fasting or even for those who are we don't see it as a long-term lifestyle, I think this is probably not a concern. It is worth remembering that any extreme intervention is likely to have detrimental effects so lets just keep to 5:2 or 6:1 in the long term.

I'm sorry I haven't posted links to the research supporting some of my statements but I can hunt them down in time if you would like to see them.

It is bound to get negative press supported by the PR people at SW WW JC CD Slim fast, Atkins etc etc as you just stop eating, no way you can make money on that!

Fantastic information Caroline even by your high standards, thank you so much. I agree with boboff that some negative press is inevitable at the moment though I think it is not so much the PR people as the journalists wanting to make a new story - even if they have to use old discredited research to do it!

Caroline, thank you so much for taking the time to advise.
While I wasn't sure the writer of the article was too well-informed, I am so grateful to hear the claims properly addressed and debunked!
As a vegetarian, I am always being asked if I get enough protein and always respond that we don't need as much as people seem to think, but the tone of the article scared me silly. This forum really is a Godsend!

caoimh wrote: Caroline really is a Godsend!

I've edited that for you caoimh!

At the risk of sounding like I reside on the paranoid conspiracy theory side of life I suspect that as 5:2 dieting grows in popularity there will be ever growing criticism in both volume and ferocity from those who stand to lose out. I'm losing weight, probably getting healthier and don't need to spend a penny to do it (actually my food bills have dropped). 5:2 or 6:1 or whatever is a simple enough way of doing things that anyone (even I) can understand - no need for (chargeable) complexity.

Eating disorders are rooted in psychological problems, but she says fasting encourages “disordered eating” and that could tip at-risk dieters into a full-blown eating disorder.

Yes, I guess it could. I've known a couple of anorexics (both now cured/healthy etc) and it's a horrible horrible condition but are they really suggesting that as there are some people with eating disorders who may tip into anorexia that none of us should fast? Using that kind of argument is really a sign that the argument is being lost...


James

Jemima wrote:

caoimh wrote: Caroline really is a Godsend!

I've edited that for you caoimh!

I am not in the overweight category but i'v still got baby weight on me as i put on a lot of weight with both of my pregnancies. I lost most of it quickly after wards but was always stuck 10-20lbs over my pre-pregnancy weight.

My BMI is 21.9, im 5ft 1, 27 years old. I'v already got 2 children and not planning on having anymore at the moment.

I want my BMI to be under 20. I want my flabby baby tummy to be gone. I want to be able to go on the beach with my family and not be embarrassed by my body. I want to feel good about myself instead of ashamed when in the bedroom with my husband. I want to be confident again and feel sexy, not embarrassed and disgusted to take my clothes off.

I don't have a lot of weight to loose. Is this diet safe for me?

As I explained in my review of the article...most of the stated fears can be dismissed. That is not to say the diet is guaranteed to be safe...but it looks unlikely that it would cause long term harm as long as you are sensible: Only fast twice a week, eat some protein on fast days (enough to get around 40-50g protein), ensure you eat normally on feed days. Don't stray into the underweight territory.

You say you have some belly fat...getting rid of that is a good thing. What is your waist measurement may I ask? Is it 10" or more smaller than your hips? Is it under half your height? If the answer to these is no, you are fine to lose a bit of weight.

If you think you might have issues around food that would put you at risk of anorexia, then no, you would be unwise to fast because of the reduced appetite you get.

The science suggests fasting twice a week may have important health benefits, we won't know for, oh, probably 30 years, if that is true.

I worry that fasting is only beneficial to overweight people and either of no benefit, or worse, have negative effects on people who uses fasting to maintain their healthy normal weight.
You're right though, we wont know for years until multiple long term studies are done on significantly large numbers of people. Thousands of people of varying body types and health issues need to be studied. Healthy normal weight people need to be studied to see if there is any benefit of fasting one day a week to maintain weight. Maybe this isn't good for us in the long term? We don't know. We should all be cautious until there is sufficient evidence that life long fasting is actually good for our health.

Im going to get a tape measure to check my waist.


Waist 87.5cm
Hips 80.5cm

You measure at the widest part of your waist and hips, right?

The 2005 study discussed was alternate day fasting for three weeks, that's zero food between midnight and midnight.. "On each fasting day, the subjects were allowed to consume energy-free beverages, tea, coffee, and sugar-free gum and were instructed to keep their water intake high."

The women were thinner than the men (22 BMI vs 25) and some differences in trial outcome were observed :-

"The women had significantly lower glucose, insulin, free fatty
acid, triacylglycerol, and LDL-cholesterol concentrations and
significantly higher HDL-cholesterol and ghrelin concentrations
than did the men (P  0.05). Fasting glucose was not significantly changed from baseline in the men or the women"

". Systolic and diastolic blood pressure were not significantly altered by the
intervention (data not shown). HDL was elevated from baseline
in the women only (P0.001; data not shown), and triacylglycerol was significantly reduced from baselineinthe men only (P
0.05; data not shown)."