Some info on milk spikes

Just a little bit of info for a topic @daisymae has mentioned a few times.

Lactose is a form of sugar found in milk. It is a disaccharide. Disaccharides are sugars made of two units of different forms of sugar. Lactose is formed from one molecule of glucose plus one of galactose.

(Another example of a disaccharide is table sugar (sucrose) which is made of fructose and glucose).

When consumed, lactose is broken into glucose and galactose. Galactose is a simple sugar. It is one of three monosaccharides (the simplest form of a sugar) found naturally in foods (the other two being glucose and fructose).

An enzyme in the small intestine called lactase breaks lactose into glucose and galactose.

Generally, lactose will not cause as fast a spike as things like glucose, fructose, or sucrose. There are no catabolic pathways that metabolize galactose directly, so the body will convert galactose into a something it can use, a metabolite of glucose.

Galactose is converted into glucose 6-phosphate in four steps. This takes a little bit longer, but ultimately you get the BG rise from it, just like you can from any of the other simple sugars.

From Biochemistry, 5th edition:

If you are still reading this, maybe you are thinking, “Why does all of this matter?!?!?”

DaisyMae has mentioned a number of times how milk and yogurt products spike her.

So I am detailing all of this to give reference why those things spike her.

Anyway, there ya go, DM. The science behind your milk and yogurt spikes.


i find this very interesting. but i am wondering about the fact that i use Lactaid Milk, but am able to eat things like cottage cheese, regular cheese, cream and 1/2 and 1/2, and old fashioned whole milk yogurt (not the GREEK kind) without much trouble. so my question is:

why some dairy products, but not others??? seems weird to me, thats all.

Correct me if I’m wrong, @Eric, but since Lactaid milk has enzymes added specifically to break down the lactose for you (for those who are lactose intolerant), does that mean drinking Lactaid milk is even worse than regular milk, because the sugar is already broken down to its easiest (and thus quickest) to digest form?

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yes; i would like to know the answer to this as well, since i drink Lactaid milk. maybe thats been my problem all along. (of course, this would not explain my problems with Greek yogurt) but, maybe i should be drinking regular milk and not the Lactaid? (i am NOT, btw, lactose intolerant, i just prefer the flavor of the Lactaid milk…maybe b/c it is sweeter :blush: )

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Not all dairy products have the same amount of lactose.

Remember, the sugar component in milk is lactose.

Lactose ===> becomes glucose and galactose

Less lactose means less glucose and galactose results from it.

(side note - when you eat malted milk balls, you are getting maltose, another type of sugar! It is also a disaccharide )

More than you wanted to know, right?

definitely not. exactly what i wanted to know. i would love to know, though, what the hell is in Greek yogurt that messes me up so much. why can i eat regular yogurt, but not the Greek kind? I LOVE Greek yogurt !

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Well, it would only make it faster for a person that IS lactose intolerant. But it would not matter for someone who is not lactose intolerant…


If you are lactose intolerance, you have a deficiency of the enzyme lactase. That is the enzyme that breaks lactose into glucose and galactose.

In lactaid milk they add lactase.

If you are lactose intolerant, the addition of lactase would make it break down, so you get the sugar. Without lactase, you don’t get as much of the sugar. So for people who are lactose intolerant, lactaid milk would make a difference compared to regular milk.

If you are not lactose intolerant, you already have the enzyme, so the fact they put more of the enzyme in the milk doesn’t matter so much.

Crap, that is a lot of stuff I wrote. Does that all make sense?!?!? I hope so.

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Well lets look at the differences:

Greek yogurt has less carbs per oz than regular yogurt
Greek yogurt has double the protein of regular yogurt
Greek yogurt has had more of the water removed to make it thick

So when you are eating greek yogurt it is less simple sugars, more protein (which is why I think it messes you up) and if you serve from a communal container I bet you serve yourself a bigger portion than if you were doing it with regular yogurt.

Forgot the fat, greek yogurt has triple the fat as regular yogurt.

So you have lots of fat and protein, which in combo are tough to deal with, ala pizza


Also just to add this, I am not saying any of this for people to think milk is bad.

Milk has so many important things in it, such as specific proteins and amino acids, calcium, vitamin D, B vitamins, potassium.

There is a reason all mammals start their lives on a milk diet! Milk is great!

Don’t buy into the “milk is bad for you” stuff. If you are able to drink milk as far as lactose tolerance, then you should drink it!

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That makes sense. I am lactose intolerant, so for me this is good to know!

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i once experimented with Greek yogurt doing a dual bolus of 50% up front and 50% over 2 hours; i experienced no spike or crash, just a nice flat line. but who the hell wants to do a 2 hour dual bolus just to have 1 glass of milk? its just easier to not drink the milk…unless of course if you are doing a dual bolus anyway for your meal.

make sense to anybody?