Were key proponents of using low-fat diets rich in carbohydrates to prevent heart disease, manipulated to make them vitriolic, highly biased, and dismissive opponents of alternate views, through mind control by the Extraterrestrial Alliance with the goal of undermining human health and well-being?

This is very much the case and you found it quite striking in reading the book recounting the history of the healthcare industry and its strange tendency to make pronouncements based on little evidence and defend them savagely, which is certainly quite unscientific conduct, but yet happens again and again across all fields of science on a regular basis. This was very much a deliberate plan of the Extraterrestrial Alliance to misdirect humans in this fashion to cause them to follow self-destructive dietary practices and is one of many ways they undermine people to drag them down, weaken them, and shorten their lives.