Indeed what he described sounds a lot like low/no-carb diet, also known as ketogenic diet. While lots of people have success on it, it isn't a panacea: the clos

Indeed what he described sounds a lot like low/no-carb diet, also known as ketogenic diet. While lots of people have success on it, it isn't a panacea: the closer you get to "normal" BMI, the more you will have to manage caloric intake, and for a minority who attempt it, ketogenic doesn't work for them at all. Lots of caveats, but one I see increasingly as more people pick up ketogenic dieting: many go overboard on the protein part, which metabolizes into carbohydrates and defeats the intent. Very, very roughly about 80% of your caloric intake will be comprised of fats, 15% protein, 5% carbs (if any appreciable amount; some will restrict down to 20g or less per day). Go slow, modify one variable at a time, focus on long-term (3+ year) consistent weight loss, accept your lapses with grace, and good luck.