That was the line that alarmed me. Advertising a shot of glucose as "removing a blockage" isn't about the wonders of fasting, it's about the fairly important problems that arise from deciding to just not eat.
Similarly, before adopting a super-low calorie diet on the basis of those "long lifespan" studies in mice, look into the part where it induces depression and agoraphobia.
Frankly, I would attribute this glucose deficiency to his diet that cut down on rice and the like. By reducing bodily supply of starch (and also lipids) they will interfere with their natural metabolic pathways such as glycogenoysis and gluconeogenesis which stabilize blood glucose levels, however without the underlying resources they cannot achieve their purpose.
Probably just mental. Vast numbers of people experience the symptoms of hypoglycemia without actually being hypoglycemic. The condition is known as Idiopathic Postprandial Syndrome.
