I cannot comment on what Dr Westman writes or proposes. I can only state on what I have learned or observed about myself, testing different foods and method of preparation.
I suspect I’m having a language barrier actually. Where what Westman means is:
“Some fiber behaves like glucose in the body”
whereas what he said is
“Some fiber is absorbed as glucose”
Which is ambiguous, and I think I took him more literally than he intended.
Doesn’t seem like pectin is the culprit.
Pectin is known to slow down the activity of enzymes that break down starches and sugar. The absorption of carbohydrates and sugars is slowed down because of pectin’s fiber content; this helps prevent blood sugar spikes, which cause glucose intolerance, weight gain and diabetes.
Doesn’t seem like cellulose is the culprit either:
In the human diet, cellulose provides fiber for the body even though the body itself cannot break the components of cellulose down. It helps in moving the small intestines when ingested and helps in defecation by being a bulking agent in feces.