"The Obesity Code" by Jason Fung goes into all the issues from the article in more detail. He references studies that seem to prove sugar substitutes cause weight gain rather than correlate with weight gain: Sucralose raises insulin by 20 percent, despite the fact that it contains no calories and no sugar. This insulin-raising effect has also been shown for other artificial sweeteners, including the “natural” sweetener stevia. Despite having a minimal effect on blood sugars, both aspartame and stevia raised insulin levels higher even than table sugar.

Fung, Jason. The Obesity Code: Unlocking the Secrets of Weight Loss (p. 172).

He has. The US refused to extradite him.

It's not the procedure itself that is sometimes painful, it's the recovery. When I had it done more than 20 years ago, I was fine with both, but the doctor proscribed me heavy duty painkillers in case the pain got bad.

He said he didn't use to, but then he had a vasectomy himself.