There's a popular myth around that yogurt is much lower in carbs than stated on the label -- that the bacterial cultures "eat" the lactose, converting it to lactic acid thus reducing the carb content by 8 grams per cup.


I have been studying and researching this to death, trying to separate fact from myth. I really, really wanted this to be true, because I LOVE yogurt, and missed having it every day.

Here's what I've found so far ..

Lactose is a disaccharide .. meaning it's composed of 2 simple sugar molecules bonded together. The 2 simple or monosaccharide sugars that make up lactose are glucose and galactose. Only glucose is converted to lactic acid. The process to ferment galactose is much more complicated and bacteria will only resort to using it when glucose has been completely used up. However the yogurt would be very, very sour by this point .. unpalatable to most tastes.

Most commercial yogurts are fermented until approximately 20 - 25% of the lactose has been converted. Then the yogurt is rapidly chilled to halt the fermentation. 20 - 25% of 12g carbs is NOT 8g .. it's 2.4 to 3g. So, commercial yogurt made from whole milk, starting out at 12g carbs per cup, will most likley have no less than 9g residual carbs in it -- not 4g. During storage, as long as the bacterial cultures truly are "live", they will continue to very slowly ferment some of the residual glucose .. but most manufacturers report that yogurt fermented beyond 30% is quite sour and considered unpalatable.

I have read the article from LowCarb Luxury a zillion times ... it's been posted and quoted all over the internet. I've lurked at the GO-diet's discussion board ... and it's stated that 4g lactose remaining per cup of yogurt applies to home-made yogurt that has been allowed to come to end-fermentation. ie -- it must be allowed to become quite sour. And I could not see anywhere that residual glucose and galactose sugar had been considered -- only lactose was tested for.


Here's some info. from the US Dairy Export Council (USDEC):
note - the link is to a pdf file ... you'll need to have Acrobat Reader installed to view it.

My conclusion is that the amount of carbohydrate which ultimately gets converted to lactic acid is much less than 8g per cup .. likely no more than 2 or 3g per cup. The residual carbs in finished yogurt consist of unsplit lactose molecules + unfermented glucose + galactose sugar.

Yogurt is a good source of calcium, and the live bacteria have many health benefits. But it is not as low-carb as some would like to believe


Doreen

Thank you for posting this. There are a couple of things to remember:

Q) A cup of milk has 14g of carbs, so how can a cup of yogurt have the same of even more carbs?
A) yogurt that is made from milk only is typically very loose and runny and the average american will not like it. Manufacturers add powderd milk to increae the of milk solids and get a thicker more creamy yogurt. and guess what happens to the carb count of such yogurt? it goes way up..




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hi Arie,

You're quite right ... And whether the starting carb content is 12g (for plain whole milk) or 14g-plus due to added ingredients ... the realistic reduction of carbs due to fermentation to lactic acid is only going to be 3g max. per cup, unless it's allowed to become very, very sour.



Doreen

I like the StoneyField farms. I belive it has 14g per cup. I find that even counting all the carbs 1/2 cup of yogurt (roughly 8g of carbs) could easily fit into my daily menu even when I was only having 20g of carbs a day.

No, it isn't for induction, and it's not a free food, but I think the health benifits of yogurt (that and the great taste) make it one of the foods worth adding in. I'm not sure about other plans, but I know Atkins allows back in fresh dairy, which includes cottage cheese and yogurt.

Now that I have upped my carbs to around 30-40 a day I can eat a little more of it. On the days I do weight lifting I add 1 cup of fat free into my protien shake for a healthy form of carbs. I still much prefer the taste of whole milk yogurt though, and love to mix it with shake mix for a mouse like treat

The yogurt debate seems to appear quite often...I wrote to Atkins people and this is what they said:

I wrote: "I have heard different opinions on whether or not yogurt is allowed on the Atkins diet, what kind is allowed and how to count the carbs (see http://www.lowcarbluxury.com/yogurt.html).

Some Atkins followers on several forums indicate that eating whole milk yogurt has definitely helped in their weight loss.

Just wondering what your opinion is on this...can we eat yogurt? Is it true about the "eating" of lactose so in fact carb counts are lower than indicated? Any suggestions on the best kind of yogurt to eat?"

And they replied:

Unfortunately, that is not true. The cultures break down lactose to glucose and galactose which allow those who are lactose intolerant to eat yogurt without discomfort. However, the full amount of sugar is still available. Yogurt along with most dairy products contain a relatively large amount of carbs. Cheese is used because the portion consumed is usually controlled. However, if one eats too much cheese they will exceed their carb levels.
Having said that about the carb count, we do not want to ignore the beneficial effect that the probiotics (beneficial bacteria) have on health. This can be obtained with a probiotic supplement . Our colon restoration formula is a good way to get these friendly bacteria without the carbs. If you really want to eat yogurt, you should select regular unflavored plain yogurt and control your portion size. You should include the carb count in your total daily intake and budget for it.

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So there you have it....

Froufie

O.K. I'l try this again, just lost it all with the Maintenace going on
I too read the earlier post about "go ahead eat your yogurt" months ago and I did, only the plain full fat one, added my own fruit,ect, then I started making my own from 2 %, and still lost all the weight I wanted.

So what should I make my yogurt from 2 % or whole milk?

Thanks for the research Doreen.
Cheers Kathy

hi Kathy,

Whatever is working for you, then continue to do that .. I just wanted readers to be aware that the "4 net grams per cup" theory doesn't hold.

I'm not at all suggesting anybody should not have yogurt .. goodness knows I love it .. For most of us who've been low-carbing a while, then adding ½ cup of fresh plain yogurt to the daily menu probably isn't going to cause a stall. But we should count all the carbs stated on the label, or maybe just subtract 1 - 1.5g from a half-cup portion.

I'd hate to see somebody think yogurt was very low in carbs and end up stalled because they were having a large portion every day

Knowledge leads to success



Doreen

Very true, but however, the way the other article was written, was like you could go whole hog, LOL

One of the reasons I feel I have done so well with this is, that Iam able to "control my servings" of many things. So it kind of boils down to everything in moderation ( with in lower carb limits of course)

So I guess I'll stick to my 2% milk to start my yogurt

Cheers Kathy

I think moderations is important, even in the LC ok things. I know some on induction for the first time were having 5 egg omlettes with a ton of cheese, 5 pieces of bacon, and 2 sausage patties for breakfast and having problems losing

Just don't tell my son yogurt may be healthy please He loves the gogurts, but I've stopped buying them because of all the sugars. I think I have him convinced that I'll make him a chocolate yogurt tomarrow though and he's excited now (basicaly it's what I eat. 1/2 cup yogurt with 1 scoop Atkins shake mix). As long as he thinks it's a treat he'll eat it

I'm interested to know how many grams would normally be in a cup of yoghurt. Us people in the UK don't really understand cup measures.

I have Greek Yoghurt most days with fruit and that has 4 g carbs per 100g or 3.5 oz. If as I suspect a cup of yoghurt is around 8 oz then that would also equate to 8 or 9 g carbs and agree with Doreen's research.

hi Anne,

Here in Canada it's even more confusing, because the container states a serving size of ½ cup = 125g. Half a US cup is technically 113g

Nonetheless, on a gram for gram basis, the label on your yogurt sounds correct.


Doreen

Just curious ...

Is there anybody else who likes plain yogurt .. well ... PLAIN?? Au naturel without "stuff" in it? I like "stuff" in it too sometimes, but mostly I just like to eat it plain.


(I feel like I've just confessed that I eat raw eggs or something like that )


Doreen

I do eat it plain, just the wholem ilk type though. It's really good. The only reason I often use shake mix, besides the taste, is to add extra protien. Because yogurt is higher carb it needs a little protien to balance it according to BFL and Atkins

I do like it plain on days I already have more then enough calories or protien, or I just don't feel like mixing it up Berries are also a good addition though. I first tried yogurt it was an organic fat free. I can belive it went down to close to 4 carbs just because of how sour and nasty that stuff was. You definetly had to mix it. The Mountian high Fat Free though is tolerable.

I like it the greek/lebanese way of mixing plain yogurt with garlic, a little lemon, salt, cut up cucumbers, and maybe a little sprinkling of mint. It makes for a very tasty salad. You can also put it over lettuce to stretch it a bit.

Gosh, thanks for the info. I've been assuming 4 grams a cup and putting it over berries...which seeminly hasn't gotten me into trouble, but now I will allow for a higher carb count.