Why Are There So Many Different Kinds of Milk?

Christian explains the difference between common types of milk, looking at calories, fat and the rest of their composition.

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Episode Transcript

Speaker 1 (00:02):
Welcome to brain stuff from how stuff works. Hey, brain stuff,
it's Christian Sager. Here. Are you ever walking around through
the grocery store and you're looking in the cases and
you see the milk and you get thirsty? But then
you say, why are there all these different colored caps?
Why is there blue and yellow and green and red?

(00:23):
And what do these things all mean? Well, all right,
let's break it down. Whole milk, which is three point
two five fat, that's the stuff that comes from a
cow before any processing. Then there are the others. There's
reduced fat milk, which is two percent fat. There's low
fat milk, which has one percent fat, and then there's

(00:44):
fat free or also known as skim milk, which has
zero percent fat, and all of those undergo processing to
remove extra fat that comes from the cream. Besides the
noticeable difference in taste, whole milk and low fat or
skim milk differ in their fat, nutrient, and calorie content.

(01:04):
So there's a lot going on under all those different caps.
Making low fat and fat free milk involves skimming cream
from whole milk out of the final product, and unfortunately,
fat soluble vitamins like D A, E and k, which
are found in the milk fat all go along with it,

(01:25):
so as a result, reduced fat, low fat and skim
milks contain lower amounts of many nutrients. But milk companies,
even some organic brands, have figured out how to add
these vitamins back in during processing to fortify the final
product with nutrients, particularly vitamins A and D. So some

(01:47):
brands also boost their product with powdered milk solids to
achieve that thick white texture that we're so accustomed to seeing.
And since fat free milk is naturally blue too, died
in pretty watery, they want to add stuff to that.
Fortification ensures that lower fat milks are nutritionally similar to

(02:09):
whole milk and can remain a significant source of vitamins
in our diet regardless. Whole milk proponents argue that fat
soluble vitamins are not as easily absorbed without the actual
milk fat present. Okay, so let's look at the whole
milk first. Whole milk must contain no less than three

(02:30):
point to five percent milk fat and eight point to
five percent quote milk solids that are not fat, And
what they mean by this is protein carbohydrates, water soluble vitamins,
and minerals. All milks are approximately eighty seven percent water.
Whole milk itself contains a hundred and fifty calories and

(02:52):
eight grams of fat per eight fluid ounce serving, although
this isn't required. Whole milk maybe fortified with vitamin A
and or D, which you know we talked about earlier.
And what whole milk does have is more fat. It
has about ten grams of fat per cup. Now, the

(03:12):
homogenization process with whole milk, that process breaks up fat
and disperses it through milk to give it a smooth,
uniform consistency. And most whole milk is homogenized to prevent
all of the fat in it from rising to the top.
And then, of the four options that I've presented here,
whole milk actually has the highest amount of saturated fat

(03:36):
and calories, with around a hundred and fifty calories compared
to skim milks nine d calories and four grams of
saturated fat per eight out serving. Now, while whole milk
has more saturated fat, this isn't necessarily a bad thing.
More and more research suggests that saturated fat may not

(03:56):
actually be unhealthy. Whole milk does contain a more cholesterol
per eight out, serving about twenty four milligrams of cholesterol
compared to skim milks five milligrams, but some studies have
found that whole milk might not increase total cholesterol and
it may actually raise good cholesterol levels. Those are HDL levels. Still,

(04:21):
given the conflicting existing research and the fact that most
diets contained plenty of sources of fat and cholesterol, most
doctors actually recommend making the switch from whole to low
fat or skim milk. So let's look at those. We've
got two percent next, and that's the reduced fat one,
and it's a good choice for those seeking moderate restriction

(04:44):
of their fat intake. Reduced fat milk is just whole
milk in which the milk fat level has been reduced
from three point to five percent to two percent. Hence
you know the popular name two percent milk. And remember
in two percent milk, vitamins A and D are removed
from the milk fat, so they have to be added

(05:05):
back in too. Reduced fat milk, just like we talked
about with fortified milk. Then you've got your one percent.
That's the low fat milk, and like it implies, it
has one percent in it. A cup has one calories,
which is about a fifth from fat, and this is
a good choice for those who are seeking a somewhat

(05:26):
greater restriction of their fat intake. This also has vitamins
A and D removed, but they are also added back
into low fat milk. Then we have skim milk. This
is the one we call fat free. Why because it
has the most fat removed or skimmed off the top,
but it has the same nutritional benefits as whole milk.

(05:48):
Non fat or skim in. A cup has about eighty calories,
but none of those are from fat. And how does
a company create fat free half and half you're probably wondering. Well,
the way they do it is by adding stuff like
corn syrup, solids, or artificial color or sugar to non
fat milk. So aside from that, if you want to

(06:09):
drink fat free milk, it's a good choice for those
who are seeking to restrict their fat take considerably. But
again they remove vitamins A and D, so they have
to be added back in the bottom line on all
of these different types of milk, drinking two to three
glasses of milk a day, whether it's skim two or whole,

(06:31):
lowers the likelihood of both heart attacks and strokes. And
while you've probably always been told to drink reduced fat milk,
the majority of scientific studies actually show that drinking whole
milk actually improves cholesterol levels, just not as much as
drinking skim does. So if you're dieting, the lower fat

(06:52):
option is an easy way to save a few calories,
but when it comes to building muscle, whole fat milk
maybe your best choice. Scientists at the University of Texas
Medical Branch in Galveston actually found that drinking whole milk
after lifting weights boosted muscle protein synthesis, which is an

(07:13):
indicator of muscle growth. In fact, it boosted it two
point eight times more than drinking skim milk did. Check
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