Day 035 - 12 Oct 94 - Page 49


     
     1        requires, a series of events occurs which consumes a fair
     2        number of those calories.  The metabolism is increased,
     3        the brain increases its secretion of a hormone called
     4        noradrenaline or norapinephrine, thyroid which elaborates
     5        a hormone called t-3 (which can just be written as t-3, if
     6        you like), that hormone is more readily activated by a
     7        high complex carbohydrate diet and, more readily
     8        inactivated to another hormone called reverse t-3 when
     9        carbohydrate has been displaced by another macro nutrient
    10        such as fat.
    11
    12        The result of all this is that a high-fat diet has a
    13        dramatic effect on the production of adipose tissue,
    14        completely aside from whatever calories it may hold.
    15
    16        In addition to that, however, fat that is in the diet,
    17        whether it is from an animal source or a vegetable source,
    18        can be added to body fat with the loss of only, perhaps,
    19        two or three per cent of its calorie content.
    20
    21        For carbohydrate, that is not possible.  When the high-fat
    22        diet is modified and the fat intake is dramatically
    23        lowered and carbohydrate is substituted, storage as fat is
    24        reduced.  Carbohydrates, we do not have little drawers or
    25        hooks for carbohydrate on our thighs or belly, so the
    26        carbohydrate molecule has to be biologically disassembled
    27        and a fat molecule made out of its constituents.  That
    28        process consumes about 23 per cent of its calories.
    29
    30        So, it is not correct to say, in spite of the fact that
    31        I know some authorities have asserted that fat is
    32        fattening simply because it is extremely dense in calories
    33         -- it is; it has two-and-a-quarter times the calorie
    34        content of carbohydrate or of protein.
    35
    36        But that is only the beginning of problem with fat as
    37        regards adiposity.  The effect on metabolism or, I should
    38        say, the lack of effect of fat and the pronounced effect
    39        of carbohydrate, and the ease with which dietary fat goes
    40        nearly unmodified into the body's fat stores in comparison
    41        with carbohydrate, which is unable to do that without
    42        losing nearly a quarter of its calorie content, those are
    43        very significant factors.  I hope that is responsive to
    44        the question.
    45
    46   Q.   So, you would not agree then, as I think I have understood
    47        what you tell us, that the effects of dietary fat on
    48        hormone metabolism are uncertain?
    49        A.  That the effects of -----
    50 
    51   Q.   Of dietary fat on hormone metabolism are uncertain? 
    52        A.  There is a great deal more that could be said than 
    53        what I have just gone into so far.  I have only scratched
    54        the surface.  There is a substantial literature (which I
    55        will not bore you with unless you are interested) on how
    56        fat affects sex hormone binding globulin which holds
    57        oestrogen and prevents it from being biologically active.
    58
    59        When different dietary groups are studied, one is
    60        interested not only in levels of estradiol oesterone or

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