I'd venture a guess that, like everything else in the world related to biology, SLD and AS don't work exactly the same for everyone. That said, it has worked for me - but there were times, particularly at the beginning, that it sure didn't seem to.
I sometimes have trouble digesting the oil - one time, after stopping for a week for travel purposes, I took about five tablespoons (all that was left in the bottle), and I had major stomach cramps and spent about an hour in the bathroom, praying for the sweet release of death. It was that bad. Wait, why am I posting this as a response to a newbie? I guess the point is, it's not a perfect system, and you can have serious hiccups (though I should note the pain went away after the second bathroom trip, almost as if by magic, it was the only time, and as far as I can tell there were no long-term consequences).
I suggest that most people who start out, take too little oil. That's a mistake. It IS important, as my little anecdote suggests, to build up to the proper dosage. But at first, don't worry about the extra calories the oil contains. Yes, you almost certainly will gain weight at the beginning if you eat the same amount, then add the oil.
But the point of SLD is really to change your eating habits, and (if it's possible, which in my case seems to be) to accustom both your body and mind to the way you feel eating less. You need the AS for that, over a period of months (at least) - and to get that, you need the ELOO or SW (I actually switched to CO, as it's a lot cheaper - I live outside the US). I suggest:
1) Gradually increase (over a period of about a week) dosage to even 2 times whatever you calculate is the proper dosage for you. Like I said, individual biology may mean that you need more than usual, and as far as I can tell, except for some potential digestive problems caused by sudden increase, there's no danger to taking "too much." You really, really need to feel the AS, and it's better (and still safe) to take too much oil than too little. It's like being in love - if you're not sure you feel it, then you don't. So the next day, take a little more (or add a second dose, although I find this too troublesome).
2) In the beginning, change where and with whom you eat. Even with the AS, it's too hard to resist the temptation to eat too much (or as much as you normally did before SLD) if you're in the same restaurant with the same large portions of the same delicious food with the same friends and family who order the same big meals as always. You need to change your eating habits, at least in the beginning (eventually, you will develop new, healthier habits, hopefully), and it won't matter so much where you are or who you're with. But at first, make a change.
3) Eventually, you should naturally (or maybe you have to do it consciously, at least for a while) develop a new standard of fullness or satiety, so that less food feels right. In my case, I used to eat three big meals a day. With the SLD, I cut it to two reasonably sized meals, plus the oil. I often slipped out, especially during holidays, and gorged (note: SLD will not stop you from gorging, although it might make it less pleasant) At some point, however, about 6-9 months (it's hard to be more specific) after I started, I realized that, even on the days I skipped the oil for some reason, I wasn't as hungry as I used to be, and I wasn't eating as much to be full. I actually felt a little nauseous trying to eat as much as I remembered I used to (my mother taught me always to finish whatever was on my plate, so if I order what I always used to, I try to finish it all). It's actually gotten to the point - surprise, surprise - where I don't actually take the oil on a consistent basis (maybe 2-3 times a week), yet my former appetite hasn't returned, and my weight stays around 78-80 kg (usually 78kg empty, 80kg full), which was my original goal.
So that's the goal - SLD is less a diet in itself than a tool that helps you change your lifetime eating habits. I think all doctors point out that that's the only basis of any permanent weight loss. The power of AS is that it enables you to make those changes, whereas most other diets simply help you lose weight temporarily, but do nothing to empower you to eat less on a more or less permanent basis.
So that's my simplified blueprint. Don't be afraid of the oil!