To keep it simple...

1). A calorie deficit is absolutely imperative to establish weight loss (excluding temporary water loss);

2) Hypocaloric high-carb and low-carb diets of equal caloric content do not produce any difference in the rate of fat loss (hypocaloric = fewer calories);

3) Carbs do not and cannot explain recent increases in obesity rates, for per capita carbohydrate intake in the US is similar today to what it was in 1909. People did not suddenly switch from eating zero-carb diets to high carb diets - in fact, the average American never ate a zero-carb or even low-carb diet.

Per capita caloric intake is higher now, but activity levels have decreased since 1909. That is why obesity rates have increased.

Thank you Anthony Colpo.

You might like to peruse a free 66 page booklet by Colpo in pdf format entitled They're All MAD .

Debunks the "metabolic advantage" nonsense put forth by the likes of Atkins and Eades that claim it's possible to gain weight on a high-carbohydrate diet but lose weight on a low-carbohydrate diet even when the 2 diets contain the exact same number of calories.