Day 033 - 10 Oct 94 - Page 56


     
     1        A.  Yes.  People tend to want to maintain a relatively
     2        constant fat intake.  It has also been shown for salt that
     3        people want to maintain the same sort of salt intake on a
     4        continuing basis.
     5
     6   Q.   Are you saying that is a psychological thing rather than a
     7        physical thing?
     8        A.  There is clearly a psychological component which
     9        I mention in one of my references on actually the last
    10        page before the references.  Birch 1992 did describe in
    11        some detail some of the psychological aspects of it using
    12        a conditioning model.  However, whether they are physical
    13        aspects, it simply is not known.
    14
    15   Q.   I did jump out of order there.  The point we have not
    16        really brought out, you say diabetes contributes to heart
    17        disease?
    18        A.  It is a well-known contributor to heart disease.  It
    19        makes atherosclerosis much more aggressive.
    20
    21   Q.   Moving on to page 4, confounding variables in studies, is
    22        that always a problem?
    23        A.  It is always something that researchers want to pay
    24        attention to.  For example, in studies I mentioned earlier
    25        of Adventists or of vegetarians, if I had group of
    26        vegetarians that had very low cancer rates but they also
    27        never smoked, and I tried to compare them with a group of
    28        people that were not vegetarians, not following a healthy
    29        diet but also smoked, it would be very difficult to sort
    30        out the variables there.  So, it is something that all
    31        researchers pay attention.
    32
    33        The study of Adventists were done in that population
    34        specifically because confounding variables can be
    35        minimised or even eliminated, because virtually all
    36        Adventists avoid tobacco; virtually all of them avoid
    37        alcohol and caffeine but half are vegetarians are half are
    38        not roughly speaking.  So that allows the confounding
    39        variables to be controlled.  When case controlled studies
    40        are done, similarly, the confounders are something which
    41        is given very high priority.
    42
    43   Q.   Moving on to page 5 -----
    44
    45   MR. JUSTICE BELL:  There are a couple of matters on page 4
    46        I would like some expansion on.  When you say in the
    47        middle paragraph:  "The high-fat foods served at
    48        McDonald's contribute to obesity", what do you mean by
    49        that?
    50        A.  That a high fat intake, irrespective of calorie 
    51        intake, encourages obesity. 
    52 
    53   Q.   Can I relate that to what you say in the next paragraph?
    54        What are you suggesting there?  I mean, on one reading of
    55        it it might be interpreted that you were saying that since
    56        there is no established threshold below which the
    57        consumption of foods which you describe is known to be
    58        safe, but eating one McDonald's meal might be a risk to
    59        your health; is that what you are saying?
    60        A.  No.  No, your Honour, that is not what I was intending

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