100 times is excessive - 30 times minimum per full mouth.
Don't know where you are getting your numbers, but mine comes from Macrobiotic "dietitians" who studied at the Kushi institute.
Not that I believe in Macrobiotics, but I appreciate some of the philosophy - chewing food thoroughly, eating local, seasonal, and organic, etc.
They go nuts about chewing, and I have heard of a cancer "treatment" that involved eating only brown rice and chewing each bite 200 times. They recommend chewing until all food becomes liquid before swallowing.
Based on this, I decided to try it myself for a month, and did not find 100 times to be "excessive".
It helped my digestion tremendously, though.
Start food combining(trophology -the science and study of food chemistry)
Definitely good advice.
I have learned about food combining and had to change my life in some difficult ways, like not eating dessert or fruit with a meal in my belly, but the positive effects have been huge. Now that I separate carbs, proteins, and fruits/sweets as much as possible, I don't even have to chew a lot to have smooth digestion most of the time.
Also never eat snacks or meals less than 2 hours aapart - 4 hours apart is the ideal.
While I agree that having a few hours with an empty stomach between meals is very healthy, I also think that there is no ideal number of hours that works perfectly for all human beings.
Each person is anatomically, physiologically, and biochemically individual.
Therefore, the sweet spot varies based on these things, and other factors (such as what you ate in your previous meal).