Yes yes calorie in calorie out blah blah. Most people can't maintain a caloric deficit for an extended duration. Countless studies have shown that.
The point is people who are overweight tend to lose weight when eating ad libitum on a ketogenic diet, whereas people on a standard diet generally gain weight (see western populations).
If you cut out cookies, cake, pretzels, chips, and virtually all other junk food of course you will lose weight. IMHO, the keto folks are missing the actual cause here. You're not losing weight because you eat your burger without a bun. It's because you don't eat a pile of fries.
1. People on western diets. This isn't some hidden mystery.. it's in plain view. Plenty of studies done, or just ask _any_ doctor that sees patients, or any of your friends/family who have tried diets. Or search pubmed for diet adherence.
2. Because their base metabolic rate reduces over time to match their new reduced caloric intake.
The point is people who are overweight tend to lose weight when eating ad libitum on a ketogenic diet, whereas people on a standard diet generally gain weight (see western populations).