In a message dated 9/11/02 4:56:10 AM, [log in to unmask] writes:

>The
>relationship between caloric intake and weight may not be linear,
>but that doesn't mean that there is no practical or relevant
>relationship at all.

Just getting around to this reply.

I personally have failed to lose weight on as little as 800 calories a day
while nursing an infant. Yet on double that amount I didn't gain either
during that period of my life. My child's pediatrician wasn't surprized --
hormones he said. Whatever relationship there exists between caloric intake
and my weight certainly isn't linear.

Just this past year, I have put on 20 pounds while eating a low carb diet
usually not exceeding 1500 calories and often as low as 1000 calories. I was
on Hormone replacement (bioidentical hormones) though.

An ongoing investigation comparing Atkins and a low calorie approach (1200
calories) using adolescent girls has found more weight loss for the Atkins
group even though they eat on average about 1800 calories a day.

>>Yes, but "more" in this context does not mean "more calories than
one burns."

The problem with the calorie reduction hypothesis is that it doesn't lend
itself to falsifiability -- according to the calorie theory one should lose a
pound of stored energy for every 3500 calorie deficit. But when the amount
needed to maintain the weight shifts with the calorie intake, with
macronutrient content, with hormonal signals and God knows what else, it
becomes rather difficult to test the hypotheses and it loses scientific
verifiability and value as an explanatory idea. If calorie reduction doesn't
lead to weight loss then the argument is always that one hasn't lowered them
enough. Slippery and slimy and hard to pin down as Mao used to say. As I said
before, calories may count someplace within the very, very complex system
known as metabolism -- but on it's own, it has little practical predictive
usefulness.

>>Moreover, the supposition that body weight and caloric intake are
not related doesn't make physiological sense.  What is body fat
for?  It's a way of storing energy.  Why do our bodies store
energy?  So that we have it when we need it.  Why would we need
it?  We need it when we can't get enough food.

At this point you are using calorie in a definitional way and the reasoning
becomes circular. I am addressing the issue of the calorie theory as a
predictive scientific hypotheses as it relates to metabolism and issues of
weight loss and gain. Will knowing the caloric value of someone's diet tell
you much about their weight, fat storage, metabolism, etc. As a scientist
that is what I want a scientific idea to do.

Wiley and Formby in Lights Out make a compelling case that a calorie is not a
calorie per se, but always a carbohydrate. Body fat is not just excess
calories; but excess carbohydrates ( fat and protein too when accompanied by
carbos) -- and that the storage of fat is part of a complex relationship
between light/season, sleep and hormones. They assert that one can never
store fat as fat if fat is eaten alone because fat doesn't provoke an insulin
response. Protein raises insulin somewhat, but it also raises glucagon and by
itself won't pack on the fat. Kekwick and Pawan demonstrated as much back in
the 50s and 60s. They put people on 1000 calorie diets that were either 90%
fat, protein or carbs. The fat group lost lots of weight; the protein group
lost some and the carb group maintained or gained. How does the calorie
hypotheses explain this? What predictive value does it have? Perhaps calories
are a more powerful predictor at lower and upper levels of consumption?
Obviously if one ate nothing, weight would come off (I tried this once -- did
it for about 4 days -- no loss, but probably didn't starve long enough). On
the other hand if one ate extreme amounts of fat or protein (if could get
past the nausea that would provoke) one might gain weight. But for my money,
the calorie theory needs to meet chaos theory to be meaningful in such a
complex system as metabolism.

Namaste, Liz
<A HREF="http://www.csun.edu/~ecm59556/Healthycarb/index.html">
http://www.csun.edu/~ecm59556/Healthycarb/index.html</A>