Scientific Evidence

Epidemiologic evidence in areas like diet (where there

is large individual variation) is very weak. The examples of false associations (heart disease correlates

with sales of TV sets) are numerous.

It is only when the epidemiology is backed up by other scientific

evidence that it has impact. The

most important epidemiologic evidence in nutrition is that during the epidemic

of obesity and diabetes, almost all of the increase in calories was due to an

increase in carbohydrates. The reason this has more force than a simple

association is that carbohydrates stimulate insulin production which is known

to be an anabolic hormone. More important, however, is that whereas association

does not prove causality, the lack of association is an argument against

causality. During the obesity – diabetes epidemic fat consumption, and even saturated

fat consumption, stayed about the same. In fact, for men the absolute number of

calories of fat or saturated fat consumed by men went down. If we were starting

from scratch without prior prejudice the burden of proof would be a low-fat

diets not low carbohydrate diets.

I summarized some of the arguments with references on the two internet

sites.