During induction you should stay away from all forms of sweeteners.
Then after induction you can try a substitute.

Look at
Splenda (www.splenda.com)
Stevia (www.stevia.com)

Both are good substitutes.

What is the actual reason for you to use sugar substitutes? Can you
just eat normal, unsweetened, natural food? Why put chemicals that
cheat your taste, in your mouth?

You are in the unduction phase, it is supposed to teach you to not
abuse sweets and bad carbs etc.

Why cheat yourself?

i

Splenda

Splenda works great.  You do have to count the carbs, though.  One packet
generally counts as one carb.  The granulated is a little weird, and I can't
remember all the numbers right now.  If you just have to have sweetener, I
would choose how many packets to use in a day and that will help you keep
track of it without worrying about it.  As you get into the other phases of
Atkins, you can use more, but you probably won't want to.  After you go
without sugar for awhile, things start tasting way too sweet, even with very
little sugar or sweetener.  That's really what the others were talking
about, I think.  You're supposed to get away from sweet cravings and
addictions, but as long as you're not eating any other sugar, it really
doesn't hurt to use a couple packets of Splenda.  I personally love tea, but
only sweetened, unsweetened makes me gag.  I also drink Diet Rite, which is
made with Splenda.  It helps me to feel like I'm not "dieting" but learning
a new way to eat by substituting some things and completely removing others.

Hope you do well with this!!!!

Amanda