Q: (Initially posted on 10/17/02) FROM KELLY B. IN PA
We consume lipids, waxes, oils, and fats, all of the time, but how many lipids
are too many lipids? Are the lipids the "Total Grams of Fat" that you see on
food products?

October 18, 2002
A: FROM MENTOR DESIREE BUTTER IN PA
Information on the different types of fat that exist in foods can be
found at: http://www.crha-health.ab.ca/hlthconn/items/fattypes.htm

October 18, 2002
A: FROM MENTOR JOAN LUSK IN RI
"Lipid" is a rather broad classification, meaning soluble in organic
solvents and not (not very) soluble in water. It includes fats
(triglycerides), but also phospholipids, cholesterol, carotene,
vitamin E, and many more. (A biochemistry textbook will illustrate
and describe these molecules.) The common way total fat in food is
measured is to extract it with an organic solvent and weigh it. This
would not distinguish between the various kinds of lipids - all would
be extracted.. But in foods the triglycerides ("fat") are the most
abundant lipid by far, so the weight of the crude fraction is a
meaningful measurement. Here's a reference on how to determine the
fat content of French fries:
http://www.terrificscience.org/lessonexchange/PACTPDF/SoxhletExtractio
n.pdf

How much fat is too much to eat depends a lot on your lifestyle and
probably on heredity too. Eskimos traditionally ate a lot of fat to
keep warm; Farley Mowatt in his books on the arctic talks about how
insufficient a carbohydrate-based diet was for them (and for him
under arctic conditions.) Sedentary people end up obese and with
clogged arteries if they eat too much fat - though there is an
alternate school of thought that blames dietary carbohydrate more
than dietary fat for those problems. Most "low fat" versions of
prepared foods have a lot more sugar added, and it's quite dubious
that they are really better for us. But it wouldn't hurt most of us
to cut down on the French fries!