Are cold starches really less fattening?

A place to get your questions answered from McDougall staff dietitian, Jeff Novick, MS, RDN.

Moderators: JeffN, Heather McDougall, carolve

Are cold starches really less fattening?

Postby healthnut13 » Sat May 26, 2012 5:27 pm

Phoenix wrote: I have heard that if you your cooked starches cold, you absorb less calories, about 10% less as it increases the amount of resistant starch by 10%. Are cold starches really less fattening?



I've been wondering the same thing...can't wait to see answer... :)
"If nothing changes...nothing changes!"
User avatar
healthnut13
 
Posts: 32
Joined: Mon Nov 01, 2010 10:44 am

Re: Are cold starches really less fattening?

Postby JeffN » Mon May 28, 2012 12:17 pm

Phoenix wrote:Are cold starches really less fattening?


There is a lot of hype out there about resistant starch, most of it has nothing to do with someone who is following the guidelines and principles recommended here.

A cooked baked potato has about 1 gram of RS per 100 grams. Increase that by 10% and you have 1.1

Cooked Brown Rice has 1.7 per 100 grams. increasing that by 10% and you have 1.87.

You said above that this is important to you in regard to, "someone who wants to lose weight." Well, the impact of this 10% would be miniscule and not relevant.

Let's take a closer look.

RS is still absorbed and yields calories but instead of the it yielding 4 cal/gram, it yields about 2 cal/gram.

Even if you consumed nothing but hot potatoes, 2000 grams would be 1860 calories. The 2000 grams would yield 20 grams of resistant starch. If you cooled the potatoes and increased the yield of RS 10%, you now have 22 grams of RS, not 20. You have 2 more grams. And those 2 grams would now yield 2 calories each and not 4. So, 2 grams x 2 calories each is 4 calories, so you would have reduced the total caloric load of the diet by 4 calories.

If you run the numbers on a 2200 calorie diet consuming nothing but brown rice, the difference will be 3.4 grams of resistant starch, and the calories saved would be 6.8

As you can see, the reduction in total calories of the food is miniscule, even if you ate nothing but cooked potatoes or brown rice.

However, understanding the principles and guidelines of calorie density, would be more important.

The average calorie density of brown rice and potatoes is about 500 cal/lb. Now, all you are talking about is increasing the amount of RS by 10% and thus, reducing a small portion of the calories absorbed.

In regard to calorie density, even if you could reduce the absorption of "all" the calories in the brown rice and the potatoes by 10%, they would now be 450 cal/lb, which is still in the exact same "range" of calorie density as before and would not have an impact to anyone following the guidelines and principles of calorie density.

Therefore, again, the impact of temperature on the RS is miniscule to anyone following this WOE..

:)

In Health
Jeff
User avatar
JeffN
 
Posts: 8359
Joined: Tue Jan 08, 2008 5:56 am

Re: Are cold starches really less fattening?

Postby JeffN » Mon May 28, 2012 1:30 pm

Phoenix wrote:That was the explanation I was looking forward since my first post! LOL :D

Crystal clear!
Thank you very much!!

Cheers,
Martin


:)

In Health
Jeff
User avatar
JeffN
 
Posts: 8359
Joined: Tue Jan 08, 2008 5:56 am

Re: Are cold starches really less fattening?

Postby JeffN » Tue May 29, 2012 8:06 am

Someone PM'd me and asked if I would comment on beans. They said beans are being touted as the food highest in RS, making up about 30% of the calories and so using beans would make a larger difference as you would only get about 70% of the calories listed.

Let's take a closer look at beans and RS.

First, most all my previous comments above apply, as you will see.

Second, to be accurate, as there are many numbers circulating on the internet about the amount of RS in foods, we will use the the current Standard Reference for Resistant Starch, which comes from this study.

Resistant starch intakes in the United States. J Am Diet Assoc. 2008 Jan;108(1):67-78.

http://www.ncbi.nlm.nih.gov/pubmed/18155991

It compiled the data on RS from many studies. It also pointed out how earlier methods of calculating RS were not accurate and used animal models, test tube analysis, etc etc and how they have tried to correct for all of this. That is why there may be varying numbers out there and why we will use the Standard Reference.

So, knowing there are some limitations on the numbers and how they are analyzed and calculated, here is the info on beans and the amount of RS per 100 grams.

Legumes - Amount of RS per 100 grams

Beans, black/brown, cooked/canned - 1.7
Beans, kidney, cooked/canned -2.0
Beans, mung, cooked- 1.6
Beans, pinto, cooked- 1.9
Beans, white, cooked/canned -4.2
Chickpeas, cooked/canned- 2.6
Cowpeas, cooked - 0.6
Lentils, cooked- 3.4
Lima beans, cooked/canned- 1.2
Peas, mature, cooked/canned - 2.6

The average of these is 2.2 grams of RS per 100 grams.

However, lets use a "best case" scenario and use one of the higher foods tested, lentils, so we really see how big the impact of RS is and how the numbers work out.

Lentils are 3.4 grams of RS per 100 grams, which is about 1/2 cup and about 116 calories. The 3.4 grams would yield about 13.6 calories if it was totally digestible. That means 12% of their calories are RS, which they say you do not absorb. Subtracting that amount from the total would lower the calorie value from 116 to 102.4

However, RS yields about 2 calories per gram so using the 2 calories per gram, instead of lowering the calories value 12%, it would only lower it 6% and the calories would go from 116 to 109.

Some actual studies have shown that RS actually yields 2.2 to 2.8 calories per gram.

("Resistant starch averaged 2.8 kcal/g for all 24 subjects but only 2.2 kcal/g in the hyperinsulinemic subjects" Resistant starch as energy. J Am Coll Nutr. 1996 Jun;15(3):248-54.)

So, if we used the 2.8 cal/gram, the calorie yield would only be lowered from 116 to 111.9, which is only 3.6%

And, that is a "best case scenario" using one of the higher legumes tests. However, according to the Standard Reference, the actual average amount of RS in beans is only about 2.2 grams per 100 grams, or about 2.2 grams per 1/2 cup cooked. So, the impact would be much lower.

On average, 100 grams of cooked beans is about 1/2 cup and about 115 calories and contains 2.2 grams of RS. The 2.2 grams of RS would yield 4.4 calories instead of 8.8 and so lower the total calories from 115 to 110.6, or about 3.8%.

At 2.8 calories per gram of RS, the 2.2 grams of RS would yield 6.16 calories instead of 8, lowering the total from 115 to 113.16 or about 1.6%

In Health
Jeff


PS From the SR Database, here is the RS in 100 grams of other recommend foods

Potatoes, baked -1.0
Potatoes, boiled -1.3
Pasta, whole-wheat, cooked- 1.4
Rice, brown, cooked- 1.7
Barley, pearled, cooked -2.4
Buckwheat groats, cooked- 1.8
Millet, cooked- 1.7
Pita, wheat- 1.3
Whole-wheat bread -1.0
Tortillas, corn- 3.0
Sweet potatoes, cooked- 0.7
Yam, cooked -1.5
User avatar
JeffN
 
Posts: 8359
Joined: Tue Jan 08, 2008 5:56 am

Re: Resistant Starch: Are cold starches really less fattenin

Postby bettina » Fri Jun 01, 2012 6:23 pm

Jeff
I really love that explanation.
I have wondered many times about the hype over resistant starch.
Thanks
bettina
 
Posts: 119
Joined: Sat Mar 27, 2010 7:20 am

Re: Resistant Starch: Are cold starches really less fattenin

Postby JeffN » Sun Jun 10, 2012 5:59 am

If you notice, neither Dr McDougall nor I have made a big deal out of it. The reason is, just like as with fiber, if you are following the guidelines & principles recommended here, you are getting it in and getting its benefit. It's just another aspect of eating a healthy diet they have identified.

This discussion in the Lounge, also helps understand the hype around resistant starch. It is in regard to claims that 30% of the calories in beans are not absorbed because of resistant starch.

viewtopic.php?f=1&t=31586&p=317181

highlights...

he says that around 30% of the calories in beans are not absorbed, due to this resistant starch.

Is this true? Actually, no. It's just another exaggeration

Let's look at the Bean Institute and what they say the research says. After all, they are in the business of marketing beans and are looking for every angle and benefit to sell beans, and are up on the latest scientific studies that promote beans.

From their website at:

http://beaninstitute.com/health-benefits/dry-beans-and-human-health/

We have utilized in vitro methods to estimate resistant starch (non-gelatinized and retrograded) in canned beans from 30 bean lines and we estimate that about 10% of bean starch in canned beans is not digestible. We predict that the amount of indigestible starch in cooked beans is 20% of the total starch content. Additional research on bean starch is warranted.


So according to the Bean Institute, between 10% and 20% of bean starch in canned beans it not digestible. So it is only a percent of the calories in the starch portion, not the total calories, which is resistant. But some take the total calories of the beans and applies the inflated 30% number.

To further illustrate how this is exaggerating this point about RS, according to the USDA Database, 100 grams of pinto beans (mature seeds, cooked, boiled, without salt) have 15.2 grams of starch and 143 calories.

Now as we saw, the Bean Institute says that 10-20% of the STARCH is resistant starch (not 10-20% of total calories).

Normally, starch yields 4 calories per gram. So that means 15.2 grams of starch contains 60.8 calories.

So let's look at this two ways: with both the 10% and 20% of calories being resistant. If 10% of the starch calories are not absorbed, that would be 10% of 60.8 calories, or 6.08 calories are not absorbed from the 100 grams of beans.

Or if it was 20% of resistant starch not absorbed, that would mean 20% of 60.8 calories, or about 12.16 calories of resistant starch is not absorbed.

So out of a total number of calories of 143 in 100 grams of beans, you are not absorbing 12.16 calories, assuming the higher 20% estimate for starch resistance that the bean institute provides.

That is about 12 calories not absorbed out of 143 calories. So that means about 8% of total calories in beans are not absorbed. Now that is a very big difference from Fuhrman's claim that 30% of total calories are not absorbed, which would be 42.9 calories.

So he asserts that you don't absorb 42.9 calories when eating 143 calories of beans, but the true figure is far lower, only 12 calories are not absorbed – using the Bean Institute's highest estimate.


In Health
Jeff


PS - This article gives a brief overview of the topic.


Resistant starch: metabolic effects and potential health benefits.

Authors
Higgins JA.
Journal
J AOAC Int. 2004 May-Jun;87(3):761-8.

Affiliation
University of Colorado Health Sciences Center, Center for Human Nutrition, Box C225, 4200 E. Ninth Ave, Denver, CO 80222, USA. Janine.Higgins@UCHSC.edu

Abstract
Although there is strong evidence that the amount and type of fat in the diet can have dramatic effects on metabolism, the case for carbohydrate subtypes influencing metabolic parameters is emerging. By definition, resistant starch (RS) is any starch that is not digested in the small intestine but passes to the large bowel. Here, RS is a good substrate for fermentation which gives rise to an increase in short-chain fatty acid production. The differing rates of absorption between RS and digestible starch are thought to denote their differential metabolic responses. RS intake is associated with several changes in metabolism which may confer some health benefits. RS intake seems to decrease postprandial glycemic and insulinemic responses, lower plasma cholesterol and triglyceride concentrations, improve whole body insulin sensitivity, increase satiety, and reduce fat storage. These properties make RS an attractive dietary target for the prevention of diseases associated with dyslipidemia and insulin resistance as well as the development of weight loss diets and dietary therapies for the treatment of Type 2 diabetes and coronary heart disease. This review analyzes the body of literature examining the metabolic effects of RS consumption and discusses possible mechanisms whereby increased short-chain fatty acid production in the bowel could account for some of these effects. The effects of RS in the large bowel per se are the topic of other reviews and are not addressed in this paper.

PMID 15287677 [PubMed - indexed for MEDLINE]
User avatar
JeffN
 
Posts: 8359
Joined: Tue Jan 08, 2008 5:56 am

Re: Are cold starches really less fattening?

Postby Debbie » Wed Jul 08, 2015 2:29 pm

Bumping this up since the news is abuzz with the newest "diet fad"!!! Im sure there will be lots of "hey you should eat that potato cold" advice going around soon. I also love how this was answered by Jeff 3 years before it was a "new thing". haha

http://newyork.cbslocal.com/2015/06/30/ ... slim-down/
"It's the food"
User avatar
Debbie
 
Posts: 2226
Joined: Tue Dec 20, 2011 6:09 pm


Return to Jeff Novick, RD

Who is online

Users browsing this forum: No registered users and 1 guest



Welcome!

Sign up to receive our regular articles, recipes, and news about upcoming events.