Banting is a low-carb, high-fat diet, named after William Banting. He is the first person who followed this lifestyle in 1861. He started following this lifestyle after trying every diet to combat obesity and as per his doctors recommendation
In following the Banting Lifestyle, you consume limited carbs and no sugars, therefore your body switches from burning carbs for energy to burning fat instead. Since you deprive your body of sugars, it's only energy source is fats, leading to weight loss. Banting is NOT a diet but a lifestyle.