I've been low carb, keto for going on 8 years. Lost over 40 pounds during the first 6 months and have kept it off since then. After following this WOE for a number of years, it's very easy to maintain, however, I'm reluctant to call it a diet. It's my lifestyle now. The dietician you're referring to may be using a semantic trick with the term "diet" to infer that they don't usually work. That would be correct, but if one embraces a way of eating as a lifestyle, then all bets are off. It's no longer a diet.

Then again, I love it when people are so definitively negative about how others live. No need to respond, as there will always be naysayers about everything and anything. It's another fascinating dynamic about human behavior.