“S” stands for “Satisfying”. Every 3 hours you have a choice, do you want to eat an “S” meal/snack or an “E” meal/snack. (And yes, you get to eat every 3 hours!!!) The “S” category includes higher fats like butter, cream, cheese and fatty meats. Guuuud stuff. Remember that every meal though is centered around protein; protein is what will be giving you energy throughout your day as well as stabilizing your metabolism.
If you have the THM book, there is a list in chapter 7. Make a copy or type it out and stick it on your fridge until memorized! I seriously thought I would never get this, however after about 2 weeks, I didn’t have to look at my list as much!