Welcome all seeking refuge from low carb dogma!

“To kill an error is as good a service as, and sometimes even better than, the establishing of a new truth or fact”
~ Charles Darwin (it's evolutionary baybeee!)

Sunday, December 11, 2011

The Latest LC Beats Other Diets Study

I'm hesitant to discuss this one, because we don't even have an abstract of a published paper.  But since it's going to be bantied about the LC web anyway, I might as well comment on what information we have.

Here's the press release from the conference at which it was presented:

Here's an article that provides some additional info:  Cutting carbs just 2 days a week can spur weight loss

Piecing together the information provided together it appears that they compared weight loss and changes in biomarkers for breast cancer risk in women over a four month period.  The diet details are sketchy, but it seems they compared the following diets:

  1. A 1500 cal/day Mediterranean-style diet, a CRD
  2. Calorie restricted low carb, 650 cal/day for 2 days per week, "Eat normally" the other 5 days 
  3. Ad libitum VLC (<50g carb/day) for 2 days per week, "Eat normally" the other 5 days 
After four months we are provided with the following results:
  • Average weight loss for "the intermittent approaches" was 9 lbs vs. about 4 pounds for the CRD.  (Not sure why they lumped them together)
  • Insulin resistance, IR, reduced by 22% for restricted LC > 14% for “ad lib” LC > 4% for Med-CRD
Low carbers are touting the following statements:
Intermittent, low-carbohydrate diets were superior in lowering blood levels of insulin, which can lead to cancer.
“It is interesting that the diet that only restricts carbohydrates but allows protein and fats is as effective as the calorie-restricted, low-carbohydrate diet,” Harvie said.
At some point I hope to see more responsibility in reporting, especially the more "official" press releases from conferences.  Although insulin can promote the growth of cancer cells, I think we need to be very careful what actually "causes" the formation of a cancer cell.  I also am getting pretty tired of the equating of normal postprandial insulin production/levels with basal hyperinsulinemia.  I think there's enough misplaced paranoia over insulin levels already in low carb circles, and I hope this type of hysteria never goes mainstream.   To say that a biomarker associated with increased risk of some disease is a "cause" of that disease is something that should also be stricken from medical reporting.  We make no strides if we acknowledge that cholesterol doesn't cause this, that, or the other thing just because LDL has been correlated with increased risk of CVD in too many studies to cite, but can't extend that to insulin.  It is the underlying pathology of insulin resistance that is the likely "cause" of the disturbed lipids and the elevated insulin levels.  

In the quote from Harvie, she displays some ignorance of how low carb diets really work (when they do), that they lead to significant spontaneous reduction in calories.  I would also question the "as effective" qualifier.  To me, a 22% reduction in IR vs. a 14% reduction is considerable.  If we were going to quantify that in a more sensational ways, we might say that intermittent calorie and carb restriction resulted in 550% greater reduction in IR than the standard diet, while intermittent ad libitum carb restriction resulted in 350% greater reduction in IR.  The addition of calorie restriction to the intermittent regime produced a 57% greater reduction in IR.  Things like that.  

It will be interesting to see what sort of evaluation of actual intake was done in this study.  Michelle Harvie has been researching calorie restriction and reduction of breast cancer risk.  Indeed another statement in the release will likely be ignored:
Weight loss and reduced insulin levels are required for breast cancer prevention, but [these levels] are difficult to achieve and maintain with conventional dietary approaches,”
So much for the overweight low carbers who claim LC is inherently healthy.  Here is one study from 2009:  Biomarkers of Dietary Energy Restriction in Women at Increased Risk of Breast Cancer.  In that study, women followed a 864 kcal/d diet for a month (26/62/12 for P/C/F percents).  Insulin levels were lowered 32% in that study.  There's a confounder here then, as modest weight loss by any means seems to improve these biomarkers.  

Let's do a little math.  Over 4 months, women on 1500 cal/day lost 4 lbs.  Assuming it's all fat (we know it's likely not, but for simplicity's sake lets) that amounts to (4lbs * 3500 cal/lb)÷(4 mo * 30.5 d/mo) ≈ 115 cal/day deficit.  Thus we can presume that these women are in energy balance at 1615 cal/day.  Thus for the restricted low carbers, consuming only 650 cal/day, they are in 965 cal deficit.  Let's do some more math:  2 d/wk * 17 wk * 965 cal/d ÷ 3500 cal/lb = 9.37 lbs.    Imagine that.  No LC magic.

There's more to this story as well.  The LC diet advised was composed of  "protein and healthy fats, such as lean meats, olives and nuts".  Nothing about fatty meats, tucking butter under the skin of chicken legs,  and drinking cream there.  Personally, I find that carbs fill me up more after a low carb day.  So the ad lib group may have eaten more on LC days than the restricted group, but perhaps ate a bit less on their "normal days" if, indeed, they lost the same amount of weight.

This is yet another study, along with the other Harvie study I cited, demonstrating that "dangerous crash diets" are not so dangerous after all.  But this study offers some strategies for folks, and isn't that what it's REALLY all about?  Let's face it, a lot of people who want to eat a low carb lifestyle, find they can't stick with it.  This leads to binging, falling off the wagon and rebounding, etc.  What this study showed was that modest weight loss can be achieved by "crashing" for only 2 days per week.  It's not specified if these were sequential or spaced throughout the week.  I know I do very well spontaneously eating not a whole lot when I eat like Jessica Biel (only I prefer tuna over salad to skinless chicken breasts), but it's not all that enticing for too long.    Imagine if these women had eaten a mildly restricted "normal diet" on the other 5 days, or done the LC for 3 days per week.    The weight loss wasn't fast, that's for sure.  But if it continued?  That's changing habits for 2 days per week to lose roughly 25 lbs in a year.  

Is this study an ultimate boast for LC?  Perhaps.  But what sort of LC?  The improvement in insulin resistance was considerable when caloric restriction was coupled with low carb.  The improvement in IR was seen for people eating high carbs the other 5 days of the week.  The improvements were seen for LC *in caloric deficit* (intentional or otherwise) with accompanying weight loss, assessed after the weight loss.  

I think this study is ultimately a feather in the cap for the intermittent fasters.  Coupled with other "crash diet" results, it seems to me that IR in the overweight/obese is a product of overnutrition.  Merely draining the tanks occasionally seems to produce marked improvements.  Since non-oxidative glucose disposal is the pathway most often identified "defective" for those with IR (as measured by impaired clearance of glucose from circulation), periodically draining not only the general fuel tank, but specifically the glycogen storage tank makes sense -- common sense -- to me as a strategy for metabolic health.  

An interesting followup would be what happens in the long run with this approach.  After a year, do they continue to lose?  Do the metabolic biomarker improvements persist if/when weight levels off?  Is there any benefit to intermittent low carbing without accompanying weight loss (I think perhaps, attributed to cyclic depletion of glycogen).  

EDIT:  A charity that supports Harvie's work had more information on their blog:
The results of the study produced effective weight loss results, with an average loss of six kilograms (13.2 pounds). Similar results were produced by women following the normal daily calorie restricted diet; the findings are important because they could give people who are overweight an alternative way to lose weight.
The intermittent diet provided the women with 650 calories (kcal) in the form of two pints of semi-skimmed milk, four portions of vegetables (80g/portion), one portion of fruit, a salty low calorie drink and a multivitamin and mineral supplement.
As OnePointFive notes in the comments, they don't even mention the ad libitum low carb arm of lean meats.  I'd also  point out that the data are different than what was presented at the conference.  The 13.2 lbs is more than the 9 lbs ... and now they say the results were similar??  Don't know what to make of this.  I would also take issue with the characterization of that 650 cal/day diet as low carb in the classic sense.  Sure, it's LC because it's so low in calories, but two pints (1 quart) of "semi-skimmed milk" -- likely 1% -- contains 415 calories, 51g carb, 9g fat and 33g protein which works out to 49%C / 20%F / 31%P.  The fruit & veggies would add more carb mostly so this could just as easily been called an intermittent very low fat diet.

I'm still curious to see if this study involved some quantification of what was actually eaten by at least a few self-report 24 hour recalls.


SamAbroad said...

I think this study is really exciting nonetheless!

I have been rather laissez-faire with my diet for the past while, tend to be strict on Mon- Tues- Wed- and then say 'fuck it' for the rest of the week. I lost 60lb with VLC (the REALLY fatty kind btw, I drank cream and put butter on EVERYTHING - but I am young and fat is exceptionally filling for me) and expected the weight to start flying back on, but I've gained 7lb in 4 months and then nothing for the past 6 months which considering how strict I was and how lax I am now before is pretty amazing!

The one downer is my energy, skin, mood and digestion is crap, but that's why I've been crawling back onto the unprocessed food wagon over the last few weeks. One day a week at a time!

Beth@WeightMaven said...

You write: "it seems to me that IR in the overweight/obese is a product of overnutrition."

I am completely with you on that. The combination of over-nutrition (especially added fructose) and lack of nutrients to support liver function, enzyme building etc certainly seems a prescription for disaster.

On a slightly related note, you've written in the past that DNL is inconsequential in terms of fat gain. I've suspected that may not allow for what happens when you are perpetually overloading the diet with carbs. Yes, there's lots of storage in terms of liver and muscle glycogen, but it certainly seems plausible that typical SAD overfeeding could easily top those off ... and then what?

That folks can get to be hundreds of pounds overweight and not diabetic (like moi) would suggest (to me anyways) that we've actually gotten pretty good at storing carbs as fat!

Have you seen this paper by Frayn et al? Whether or not upregulated DNL contributes much to fat storage or not, to this lay mind it would seem to imply a role in contributing to IR. Thoughts?

Lerner said...

The claim that "reduced insulin levels are required for breast cancer prevention" seems quite odd. I somehow don't think that claim qualifies as accepted medical fact :)

Harry said...

Hi Beth

"That folks can get to be hundreds of pounds overweight and not diabetic (like moi) would suggest (to me anyways) that we've actually gotten pretty good at storing carbs as fat!"

As I understand it, dietary carbohydrate down-regulates the oxidation of dietary fat for energy, and up-regulates the storage of dietary fat in the adipose tissue. So, basically, in a high carb/excess calorie environment, almost all of the fat you eat is going straight to storage.

So, you don't actually need any DNL to get over-weight on high carb/high just need a modicum of dietary fat that goes straight into the fat tissue.

DNL would only be a necessary factor is cases where high carb/high calorie was combined with extremely low dietary fat intake (which is atypical with most diets that provide excess calories i.e. the high carb/high fat SAD).


Lerner said...

@Beth, there is the Acheson study on massive overfeeding of carbs, which I've previously referred to here at Evelyn's, which says exactly what you are referring to. In fact, that is what convinced me to NOT do a narrow window IF. I think those that do are taking a big risk.

And, since I've been busily brushing up on my Flash skills, here is a quick animation showing my rendition of one way how Pattern B LDL can result from such:

simpleton said...
This comment has been removed by the author.
Beth@WeightMaven said...

Lerner, thanks! This is what confuses me ... some researchers do suggest that DNL could be up-regulated. And maybe it could. But I guess that doesn't necessarily mean that DNL is responsible for lots of fat gain.

Anyways, just for grins I computed a day's worth of calories eating at McDonalds. My sample menu comes to:

calories: 2980
fat calories: 1300
carb cals: 1368
protein cals: 332

I chose McDonalds, but I suppose this could easily be the kind of breakdown for any SAD meal. My takeaway is that even supposedly carb-rich meals (my meal had 2 large fries and a hash brown in addition to 3 sandwiches) may not provide more than a day's worth of carb calories. An entire medium pizza at Pizza Hut is just 800 calories worth of carbs.

So you wouldn't need a lot of DNL if your body is preferentially using the carbs for energy while storing the fat (tho this might vary depending on how much of your CHO is fructose).

In fact, the existence of the low-carb flu seems to support that there's not a lot of fat burning going on (if there were, presumably there'd be sufficient enzymes to burn fat in the absence of carbs) in the average overweight/obese person.

bentleyj74 said...

I think there's good evidence suggesting that DNL can upregulate but once again it comes back to myopia over the exact mechanism of fat storage while Rome burns. The body has to do something other than say uncle and beg for mercy to deal with the excess.

Re the low carb flu...I dip into fat burning on a regular basis and my natural appetite leans higher carb than I would have expected [70% ish] but I only experience LC flu eating LC.

bentleyj74 said...

On an unrelated note I reread the entire food reward series and no longer disagree with the theory on any point. That is all. :)

OnePointFive said...

Interestingly, the Breast Cancer charity that sponsored the research by Dr Harvie doesn't even mention the low carb'arm' just that both the normal low carlorie diet and the intermittent diet worked. The ID was "650 calories (kcal) in the form of two pints of semi-skimmed milk, four portions of vegetables (80g/portion), one portion of fruit, a salty low calorie drink and a multivitamin and mineral supplement."
The link they give to the diet doesn't work but I found this leaflet on the site which gives a bit (not much more) info on both the types of foods suggested for the med diet and the low calorie intermittent diet

Evelyn aka CarbSane said...

Yeah OPF, I'm going to edit in some of that. The 650 cal diet could just as easily be called intermittent VLF, or intermittent PSMF, etc. Most low carbers would not consider semi-skimmed milk "acceptable".

@Beth: I'll have a look at the Frayn paper. I think Harry & Lerner pretty much answered the other part of your question. I also wonder, if we have DNL pathways in our muscles to "futile cycle off excesses", what's to say these pathways aren't part of normal metabolism?

Evelyn aka CarbSane said...

@Sam: I agree. While the 2 days are a bit extreme, the overall approach is rather moderate.

OnePointFive said...

Ah ha, sorry,might need to redit again. This is the study reported in the Genesis blog, it was published 6 months ago. Comparison between intermittent or continuous energy restriction

Diana said...

"Coupled with other "crash diet" results, it seems to me that IR in the overweight/obese is a product of overnutrition. Merely draining the tanks occasionally seems to produce marked improvements.."

IF worked for me! In looking back on my 23-pound weight loss odyssey, I see that IFing was the key. That, and markedly increasing my exercise levels - but I think the latter was a consequence of the former's effects.

I've been injured and thus unable (maybe unwilling) to exercise to my customary level. Also the weather is getting cold. And I've been eating pretty SADly - but I've only gained 2-3 pounds. The reason is that even if my diet is SAD, I'm not pigging out on huge portions.

I'm coming down on the side that the poison is in the dose, mostly.

It would probably be optimal to combine portion control with a non-SAD diet. That's my latest challenge. Put the best of both together.

And don't do stupid shit when you exercise, which causes injury....!!!

PS - I discovered IF before I even knew there was an IF community (and concomitant dogma) by reading Dr. Melvin Konner, who is one of the inspirations of the Paleo movement. He pointed out in a paper that one of the reasons hunter-gatherer people are lean is because they occasionally starved. Duh, but it sometimes take an expert to point out the obvious. I figured that if they could do it without ill effect, I could do it. I had to overcome a great deal of psych resistance to fasting, because I've been brainwashed into the idea that fasting is starving, and starving is bad for you. Well, starving is bad for you - but fasting isn't starving.

Sue said...

Diana, I think you are told that if you fast or starve yourself once you commence eating you won't be able to stop, you'll make bad food choices and most will be stored as fat.
I like IF. I've just joined gym and really pushing myself, maybe I should take it a tad easy!

eulerandothers said...

This should be interesting:

given this:

Diana said...

@Sue, sorry for being lazy and not distinguishing between fasting and starving. Fasting is a short-term "draining of the tanks" and from everything I've read, it's good for you. Starving is long-term nutrient deprivation and is very bad, even possibly making bad epigenetic changes.

Overcompensation after a fast? Not necessarily. Depends on your frame of mind.

After starvation? Virtually inevitable.

"maybe I should take it a tad easy!"

You are talking to someone with a lifetime of "stupid athletic tricks" (apologies to Letterman).

Luckily for the most part I've avoided injury. My luck ran out. I've learned my lesson. A couple of hours of gentle movement is as good as shorter vigorous effort. If you've got the time.

Evelyn aka CarbSane said...

Put those into the library for now euler. LOTS of stuff all over the map for breast cancer. There are a lot of conflicting reports, reports of minor differences, etc. In the end, weight loss seems to be a key for overweight.

Evelyn aka CarbSane said...

Hi Sue & Diana, What Sue says is so true ... and perhaps some of the worst advice out there. The whole never skip breakfast, never skip a meal, it's "dangerous" to eat less than 1200 cal/day (sometimes that rule is bent down to 1000, but I seem to remember the ladies mags all parroting the 1200 number) ... all of it is nonsense. Further it sets up that self fulfilling prophecy. I think that's why LC works so well for me -- to a point -- because I can string together many days of what turns out to be very low calories w/o feeling deprived, and with my cheating plan I just ate "normally" or perhaps just a tad over maintenance. In the end it's the cumulative caloric deficit.

This study has me motivated to try a new plan. It's funny this is being hailed by the low carbers. What's with that *restriction* word there?? LOL

Evelyn aka CarbSane said...

@Lerner: Good point as well here. Reduction of risk does not equal prevention. I know plenty of slim women who've gotten breast cancer.

Galina L. said...

Looks like I am very late to comments again. I just want to say there are so many variables in the diet, you can call it any name. My take from it - intermittent calories restriction is beneficial . For satiety purpose it is more easy to limit carbs. Probably, such intermittent diet will provide the lowest baseline blood sugar. I wish they would include a group with 2 complete fasting days instead 2 LC low-calorie days to see how IF differs from calorie restrictive LC. I understand, not everybody will comply with complete fast, it just be nice to see the difference.

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