Honestly, many of us would immediately reject the idea because none of us knows the feeling of being stranded without any food for many days, under heating sun or bone shivering cold weather. Self-cannibalism could seem like the only way of survival at such point.
No. If you're stranded on a desert island and your only options are to die from starvation or die from injury sustained while eating yourself (which in itself is an attempt to survive), I'd rather die from starvation.
If someone told me I was gonna be killed unless I ate myself I'd still rather die I think.