>This is incorrect. Yogurt's bacteria secrete the lactase enzyme (beta->galactosidase) which hydrolyses the lactose ...

I forgot to respond to this. I had cited the URL http://www.danonevitapole.com/extra...ile/DWN02US.pdf

If you go to page 15 of this site, you'll see a picture of the process. Note that the beta-galactosidase is *not* secreted. It's within the bacterial cell. The lactose is take up whole using a permease transporter and some other transporter that isn't defined but seems to involve phosphorylation.

You'll also see that some of the galactose is fermented to acetic acid and some is resecreted. It doesn't say how much. Probably each species is slightly different in this respect.

Yes, one can clearly see that's so from the diagram. Thank you for the correction and the link :thup:

Nonetheless, which species of bacteria are used, whether the bacteria take up lactose inside or outside the cell wall, or what type of acid is produced is irrelevant to the carb content of the finished yogurt.

It seems the more reading I do on the subject only serves to reinforce my skepticism of the "4 g carbs remaining per cup" claim. For instance ... in the same document you linked to above ... http://www.danonevitapole.com/extra...ile/DWN02US.pdf ..:

(page 5) During milk fermentation, about 20-30% of the lactose in milk is fermented by lactic acid bacteria ...

Even for home-made yogurt, using whole (full fat) milk with no added milk solids ... you're starting with 11.5g carbs per cup. 20 - 30% of that would only be 2.3 - 3.4g reduction, not 8g as claimed. 8g is nearly 70% of the 11.5g you started with ... the yogurt would be very, very sour with that much lactic acid :eek:

I wonder if Dr. Goldberg's original testing was done using home-made yogurt that was fermented until quite sour? If you have a look at his old website, from the mid-90's prior to publishing the original GO-diet book ... http://members.tripod.com/~himolocarb/ .. you'll see his recipe for making home-made yogurt instructs you to let it ferment for up to 48 hrs, and this will give a "tarter" flavor. He then states that this yogurt should be counted as 4g per cup. Also, on his old message board, in response to a question from a diabetic concerned about the carbs, he replied:
Taken to complete end fermentation ... one would imagine that means very, very sour.

:confused:


Doreen

Just wanted to add a comment about yogurt and kefir and other lactic fermented foods .. I think they are terrific, healthful foods, and intend to include a serving every day :thup: I won't count as only 4g per cup though ;)

Yogurt may contribute to weight loss by other means rather than being super low in carbs. As Gritchen noted in an earlier post, yogurt is very low glycemic .. meaning it causes a very slow rise in blood sugar. This is because the yogurt is thick ... the lactic acid coagulates the proteins, thus it moves more slowly through the small intestine. Also, there's evidence that acidic foods will slow the transit of food into the small intestine, thus slowing the rate of absorption and reducing the likelihood of blood sugar and insulin spikes. Rick Mendosa discusses this at his Glycemic Index website.

In addition, lactic fermented foods enhance the absorption of important minerals, especially calcium. Recent studies suggest that increasing calcium intake can boost weight loss efforts .. http://forum.lowcarber.org/showthre...ghlight=calcium

:idea:


Doreen

Just curious Gritchen .. would you happen to be Gretchen as in Gretchen Becker, co-author of the Four Corners Diet book? :cool: Kewl. I have the book right here beside me :D


Doreen

1. Dang!! You blew my cover. This is one reason I wanted to add information when I read that Dr. Goldberg's results were being called "a myth."

2. Perhaps we should have said that "the carb content of yogurt can be as low as 4 g (even less in kefir)." The carb content will vary depending on the brand of yogurt, whether or not they've added milk solids, and the fermentation time. Read ingredients. If they thicken with cornstarch, or add fruit, obviously it's going to contain more carbs. If they add milk solids it's going to contain more carbs.

3. The length of fermentation to get the carbs down depends on the temperature. Commercial plants probably uses 37 degrees C or 98.6 degrees F, and they ferment until it reaches a specified pH. Dr. Goldberg's comments about "up to 48 hours" referred to fermentation at room temperature, which would take a lot longer, and he recommends fermenting until the process has stopped. The best test is to taste a little of the yogurt. I let mine get quite tart. There's nothing wrong with that. The acid slows down digestion, and when you sweeten with fake sugar, it doesn't matter how tart it was.

My sister used to make yogurt that didn't require any sugar at all. At the time I thought this was wonderful. Now I know the reason it was sweet was that it wasn't fully fermented.

4. Danon's comment about only 30% of the lactose being removed refers to Danon's own methods. They don't say what they are. When asked how far the yogurt had fermented when it reached the store, one company said they didn't know. Because most commercial yogurts are thickened with cornstarch, pectin, or something similar because Americans like "custard style" yogurt, they don't care how far the yogurt ferments. Dr. Goldberg's comment refers to end fermentation, fermenting until it's so acid that the bacteria can't ferment any more.

5. If you're doing Atkins Induction, and need a very low carb count, and if you're not making your own yogurt, it would be safer to count the amount on the package. Then if anything, you're eating fewer carbs than you thought.

Alternatively, you can try adding yogurt using the 4-g figure and track what happens with your rate of weight loss with the particular brand of yogurt that you prefer.

If you're doing LC to control diabetes, use your meter to see how much the particular brand of yogurt that you prefer raises your blood sugar.

6. If you're following the Four Corners/GO diet, the carb count is more liberal than Atkins Induction (50 g of net carbs a day), and a few extra carbs in a yogurt that hadn't been taken to end fermentation probably wouldn't have a great impact. If it filled you up and kept you from eating other carbier desserts, it would help.

7. Finally, a few techie matters:

a. I think it *does* matter whether the galactosidase is excreted and the lactose is broken down outside the bacterial cell or whether the lactose is taken up and the process occurs within the cell. If the lactose is within the cells, even if they haven't fermented the resulting glucose, that glucose isn't available to you unless you digest the bacteria. If the lactose is broken down outside the cell, then you have free glucose in your gut, and it would be taken up by your gut cells.

b. A USDA publication called "Sugar Content of Foods" or something like that indicated that in whole milk, lactose is the only significant sugar [others are all listed as zero, but total sugars are slightly higher than the lactose]. They also give figures for "yogurt" that are higher than 4 g, but they don't say anything about what kind of yogurt.

c. The figure at the Danon site said that some galactose is secreted by the bacteria, and the USDA publication showed some galactose in "yogurt." If people are analyzing lactose by digesting it with galactosidase, then measuring the galactose, and multiplying by 2 (because each galactose in lactose would be accompanied by a glucose that you're not measuring), the results would *overestimate* the amount of lactose.

They may have some way of controlling for this by first measuring galactose, then digesting with galactosidase, and then retesting for galactose. I don't know.

four corners
 

i have the book, you can have 15 carbs each meal for a total of 60 carbs a day...the usual vegies, one half cup berries per day (or other lowcarb fruit) no more than one half cup nuts per day, at least one cup og yogurt or kefir or buttermilk per day, 2 crispbreads (wasa or the like) cheese, eggs, meat no restriction on any of the no carb foodsm cream with your coffee, almond milk, only 2 carbs, and a serving of very high fiber cereal like allbran. and yes you can get greek yogurt , at least where i am in b.c., the balkan is ok but still not the same as greek; it is creamy and yummy.

I love Greek yogurt and strained yogurt, however, I don't believe the carbs magically don't count. I do eat it but I count all of the carbs.

I think the reason some people find they are successful eating yogurt is that they are ready to increase carbs, climbing the carb ladder, but haven't done it.

The extra 20 or so carbs from yogurt/other foods doesn't hurt weight loss, because that is how many carbs the person can eat and still lose.

I really think it is the sugar and processed fruit that many yogurts have included that causes the problem, not the yogurt.