Wuzzy
Sat, Apr-27-02, 23:39
Thanks Jay, worked like a charm:
I used only the following to compare which ones are worse..
X-variable: Spaghetti/pasta w/ tomato sauce-times/mo potatoes
white bread/rolls rice
It seems i may be wrong, Potatoes accounted for more of the
variance. Nonetheless, a serving of pasta is worse than a
serving of potatoes as can be told from the coefficient. Oddly
bread had the lowest coefficient.
I think a more accurate way for me to have tested this is to
do quartiles of glycemic index and compare the means of
bread, potatoes and pasta this would have told me exactly how
each of them affects GI. With regression potatoes rice etc.
are just acting as "proxies" for other nutrients that predict
glycemic index.. I don't even know whether people are eating
alot of pasta or not from the equation nor how it alone
affects the GI score.
Method: Stepwise
Steps P R-Square Corrected
potatoes(+) 0 0.161067702 0.160976335 white bread 0
0.230876067 0.23070852 rice(+) 0 0.333380935 0.333163086
Spaghetti/pasta 6.3E-70 0.355692651 0.355411877
Summary N R R-Square Std.Error normal 9184 0.5963 0.355692651
12.6627914 corrected 0.5961 0.355411877
Equation 95% Coeffici Conf. (±)Std.Error T P Constant 19.508
0.5271 0.268930804 72.54 0 Spaghetti/pasta 0.6543 0.0719
0.036703879 17.82 6.3492E-70 potatoes 0.6315 0.0294
0.015005784 42.08 0 white bread 0.2152 0.0131 0.006701195
32.12 0 rice 0.5100 0.026 0.013747751 37.10 0
Analysis of variance Sum of Squares Degrees of Freedom Mean
Square F P
Regress 812523.7848 4 203130.9462 1266.826636 0 Residue
1471818.56 9179 160.3462861 Total 2284342.345 9183 248.757742
I used only the following to compare which ones are worse..
X-variable: Spaghetti/pasta w/ tomato sauce-times/mo potatoes
white bread/rolls rice
It seems i may be wrong, Potatoes accounted for more of the
variance. Nonetheless, a serving of pasta is worse than a
serving of potatoes as can be told from the coefficient. Oddly
bread had the lowest coefficient.
I think a more accurate way for me to have tested this is to
do quartiles of glycemic index and compare the means of
bread, potatoes and pasta this would have told me exactly how
each of them affects GI. With regression potatoes rice etc.
are just acting as "proxies" for other nutrients that predict
glycemic index.. I don't even know whether people are eating
alot of pasta or not from the equation nor how it alone
affects the GI score.
Method: Stepwise
Steps P R-Square Corrected
potatoes(+) 0 0.161067702 0.160976335 white bread 0
0.230876067 0.23070852 rice(+) 0 0.333380935 0.333163086
Spaghetti/pasta 6.3E-70 0.355692651 0.355411877
Summary N R R-Square Std.Error normal 9184 0.5963 0.355692651
12.6627914 corrected 0.5961 0.355411877
Equation 95% Coeffici Conf. (±)Std.Error T P Constant 19.508
0.5271 0.268930804 72.54 0 Spaghetti/pasta 0.6543 0.0719
0.036703879 17.82 6.3492E-70 potatoes 0.6315 0.0294
0.015005784 42.08 0 white bread 0.2152 0.0131 0.006701195
32.12 0 rice 0.5100 0.026 0.013747751 37.10 0
Analysis of variance Sum of Squares Degrees of Freedom Mean
Square F P
Regress 812523.7848 4 203130.9462 1266.826636 0 Residue
1471818.56 9179 160.3462861 Total 2284342.345 9183 248.757742