Several years ago, I started hearing about the benefits of calorie restriction (CR) where individuals reduced their intakes to 60 to 85 percent of daily energy needs. Both animal and human studies showed that restricting caloric intake to these levels improved glucose tolerance and insulin action; lowered blood pressure and heart rate; and reduced oxidative damage to lipids, proteins and DNA. Animal studies suggest that CR increases average and maximal lifespan, lowers rates of kidney disease and protects neurons from degeneration.

Just this week, I learned about alternated day fasting (ADF) or alternate day modified fasting though a quick PubMed review tells me that the research has been going on for several years. Studies of ADF show similar results to CR but greater compliance. ADF regimens involve alternating days of eating as desired with days of complete fasting or severely restricted intake (maybe down to 20 percent of usual intake).

In rodents, ADF lowered fasting glucose concentrations after 20 weeks. When humans followed the ADF plan for three weeks, they did not have improvements in fasting blood glucose, but they did show improved measures of insulin sensitivity (less insulin response to a test meal). Perhaps they would have also shown lowered fasting blood glucose if the study had been longer. Both animal and human studies suggest less risk of other chronic diseases including cardiovascular disease as well.

The thought of following a CR plan sounds just dreadful to me. I imagine that quality of life must be severely affected. Though I’m not about to jump into a ADF plan, it does seem far more reasonable with similar results. It also makes me wonder about the health benefits of religious fasting.

I’m curious to know what you all think about this. I learned about ADF when talking to an obesity and metabolism researcher about resting energy expenditure and pros and cons of fasting. There are many papers on ADF. If you’re interested in a brief review, check out this one. Varady K, Hellerstein M. Alternate-day fasting and chronic disease prevention: a review of human and animal trials. American Journal of Clinical Nutrition, Vol. 86,  No. 1, 7-13, July 2007 (http://www.ajcn.org/cgi/content/full/86/1/7).

Calorie Restriction with adequate nutrition is extremely helpful for all people, and definitely for T2DM overweight individuals.  You can check out www.calorierestriction.org  for further information on this idea. 

Let's face it. Americans eat like pigs--how else is our obesity epidemic occurring?  Learning to eat slightly less, down-regulating one's appetite, while eating very healthily, and maximizing the healthy quality of all food intake can only be a huge benefit to people.  Learning to stop eating just when one starts feeling full, and not when all the food is gone or one's stomach is completely packed is a key to helping diabetic patients.  

And, let's be honest, the majority of us working in offices and sitting most of our working lives don't need to snack 1-2 times a day.  People just eat too much food! 

I think it's socially easier to be eating, even a healthy diet, than to be continually fasting. Eating normally and then fasting doesn't really teach new ways of looking at food, cooking, and amounts to eat.  CR definitely teaches people how to eat at every meal correctly, without gluttony, without any of the junk and crap that somehow actually falls into the category of "food" in American society. 

Is sugary soda pop, breakfast pastries in a box, candy bars, actually "food"--not really.  Just junk labelled under the auspices of being "food".  A wildly inappropriate ADA diabetic brochure says "Sure you can have chocolate cake if you are a diabetic, just eat less pasta at supper", but that's why people following the faulty ADA struggle to have their diabetics at A1Cs of less than 5.5%, and wind up going blind, having their toes cut off or live on dialysis. The ADA's inability to have a clue regarding dietary advice to diabetic patients is a sad situation and causes untold progression of diabetes in patients.  

Among doing the necessity of a low CHO diet, people with diabetes and pre-diabetes and Americans in general need to learn to eat less, way less, ensuring everything they do ingest is highly nutritious.  By having patients down-regulate appetite and quantity of food eaten, while focusing on produce and protein, insulin resistance is eradicated to a large extent, and appetite hormones are in proper action, active in telling patients to stop eating when they should stop eating.   It's a win-win situation all around for patients and practitioners.

So, CR makes good sense to me, if a patient will agree to do so. 

Dr. Morstein

Thanks for starting off this discussion. I often hear about alternate-day modified fasting from people who want to lose weight. I've never been a fan of this, because it's too much of a restrictive mentality. My focus is always on helping people figure out a healthy way of eating that they can incorporate into their life, not a restrictive diet.

I'm wondering if there's any research on the length of time that people have followed alternate-day modified fasting? I know that many people follow CR for years, and to them it becomes their normal way of eating. Does the same thing happen with the alternate-day modified fasting?

This is definitely an interesting discussion!

I agree with Lynn, I would not reccommend alternate day-modified fasting.  You become too focused on how hungry you are because you are fasting, which leads you to overeat when it is ok to eat.  Now that Lent is upon the Roman Catholic Community we are supposed to fast on certain days, like Good Friday.  I HATE Good Friday, because all day, all I think about what I am going to eat for dinner, and of course, you can't eat meat on Good Friday, so all i want to do is eat steak and I feel as if I overeat at that meal "just because I can".    I can see how alternate day-modified fasting could be disastrous to those who try. I would reccommend calorie restricition over ADF any day.

Judy, your comments interest me because in studies ADF has greater compliance than CR. In CR, individuals are eating well below their needs everyday, presumably for their whole lives. In ADF, they eat 100% of their needs half the time and severely limit their intake the other half of the time. The idea here is not weight loss. CR and ADF are being studied as a way to prevent disease, including diabetes, and increase longevity. I'm not interested in either one for me, but I can see why studies find higher compliance in ADF, and I can see why health minded people are interested in this as a prevention strategy. It does suggest to me that fasting now and then is good for us. Until I learned about ADF, I never would have thought that. Or maybe that's my excuse because I hate being hungry!

I should add that there are far fewer papers on ADF than there are for CR. And the ADF studies are not long term. But I do know that a lot of researchers are pretty excited about what they've observed.

Thanks for your thoughts Jill.  Now I am going to look up some studies on ADR and read up on it. I would have thought those folks ate more because they felt deprived!  I look foward to reading about it. Thanks!

Judy, you can start with the review paper I referenced in my first post. There are others and more recent ones too, but they are not yet free on the web. At least none that I found. I'm hoping someone on this forum knows more about this because I would like to learn from someone with experience. Like you, I can't stand fasting. I'm miserable and thinking about food all the time. I've always said that fasting served no healthful purpose, but I'm thinking that I've been wrong all along.

Again, I'm not an RD, but I am a NP, CDE.  I think that we have to be very careful in our recommendations to patients  with diabetes regarding both calorie restriction, and certainly alternate day fasting.  For people without diabetes, It's an entirely different issue, but since this is Present Diabetes, I'll expound.

Obviously, fasting for a person with type 1 diabetes can be dangerous.  People with type 1 diabetes will break down fats in an attempt to fuel body cells, and become ketotic.  Fatty acid breakdown triggers acidosis.  after 5 years with type 1 diabetes, the counter regulatory system is no longer functioning normally.  Ketosis is the problem.   There is data from patients with type 1 diabetes and who have followed the "Atkins diet",  that demonstrates that this can potentially result in death.  Just to review, they may have totally normal blood glucose values, if they've kept up with insulin requirements, but acidosis in and of itself, carries a 5 to 10 % mortality rate even in experienced medical centers.  The length of time, it takes a patient with type 1 diabetes to become frankly ketotic, varies enormously, and cannot accurately be predicted.  Since we can't know who is reading this, and not commenting, I wanted to be sure, it was clarified that this is NOT a recommendation any of us is making for patients with type 1 diabetes.

Now to address the needs of those with type 2 diabetes.  I agree that as a society we all overeat.  Our fast food restuarants want to "biggie" everything we order.  You only have to walk through a mall in the United States and you see our obesity epidemic.  In Europe, serving sizes in restuarants are significantly smaller, as are the people, cars, living spaces, all of it.   As diabetes educators, we want our patients to try to achieve a healthy balance of food, activity and medications.  Whereas I think we could all conceive of a type 2 regimen that would work for patients on a restricted carbohydrate diet consistently, how successful do your think, your average patient with type 2 diabetes would be at making the daily adjustments required to manage alternate day fasting?  In my experience, there are only a handful of patients I've seen where I'd be comfortable with this idea, and all of them would have to be on multiple daily insulin injections.  The blood levels of oral agents, can take days to weeks to be adjusted, and would never be safe with alternate day fasting, unless the patient was getting no meds, or perhaps only metformin, and even then I'd be concerned.

As a diabetes educator, I share everyone's concern re our poor successes with weight loss, and our ever growing epidemic of obesity.  I don't know what the answer is, but I, for one, am pretty sure, it's not alternate day fasting, for our patients with diabetes, anyway.

Also from an educational standpoint, what does alternate day fasting teach?  Continue to pig out, but only every other day?

My understanding is that ADF is being studied as a prevention strategy for type 2 diabetes (as well as CVD). I agree that it would be rare, if not impossible, to use this strategy in people who already have the disease. But since initial studies suggest improved insulin sensitivity, I think some researchers are anxious to see more and longer studies. But as I said before, this is a strategy that doesn't appeal to me.  

Jill,

I understand the prevention piece, and I apologize if my comments came across as judgmental.  I was just concerned re the whole education peice of alternate day fasting and what we're actually teaching, even those with pre-diabetes or those at risk.

Donna

Not even a dot.