I’m thinking that’s because so many more calories are available from carbs, so it’s the “low carbs” that lower the calories. Also, anecdotally, it seems to me that a meal of bacon and eggs satisfies the appetite in a way that leads to lower food intake in general, including carbs of course.
No way you can call that a reduction in calories and I have lost 20 pounds in the last 4 or 5 weeks. It helps that I seem to have lost the taste for most foods I used to love. No carbs = no hunger, try it for yourself.
The rising cost of food may force me into the cheaper carbs to survive, but that will not negate the reality that a carbless diet lowers cholesterol, and blood pressure, also fixes HBA1c.