options nodate nonumber;
data diet;
input level food;
datalines;
0.25 12.7 
0.25 7.2
0.25 14.8
0.25 5.6 
0.65 11.9
0.65 10.7
0.65 10.1
0.65 10.8
0.65 14.7
1.30 8.8
1.30 8.3
1.30 16.2
1.30 7.7
1.30 14.5
1.71 13.5
1.71 11.6
1.71 10.0
1.71 12.3
;
proc reg;
model food = level;
run;