slider in CAS also work, but for a limited time. I have had a couple of sims who were overweight and I used it and it only helped for a short time. One was a male who would be seen as a hunk (genetics, his dad had a great body also) and never had a problem with his weight, ate when his hunger was low but not real low, not yellow. He became pregnant (had SEA then) with an alien baby and after the baby was born, he had gained a lot of weight. He had to work out constantly and watch how much he ate.
Female was on the chubby side when she married my sim. She slimed down using the exercise equipment; had the baby and the weight was back on. Had her work out and she lost it but it came right back on as soon as she quit working out.
Used the LTR weight machine, can't remember what it was called, could slim a sim down or give them weight for the skinny ones.
It also worked for only a while; if she didn't work out she put the weight back on.
Adopted sims, had skinny ones at children or teen and when they would age up be seriously overweight Changed them in CAS and it worked for a few days, then right back to the weight.
They had to work out every day to keep the nice figure.
If the slider says she is to be on the chubby side, overweight, then she will be unless she works out every day or at the least every other day.