Low-carb diets, especially very low-carb diets, may lead to greater short-term weight loss than do low-fat diets. But most studies have found that at 12 or 24 months, the benefits of a low-carb diet are not very large. A 2015 review found that higher protein, low-carbohydrate diets may offer a slight advantage in terms of weight loss and loss of fat mass compared with a normal protein diet.
Low carb, high fat diets have been used for centuries by doctors when working with obese patients. William Banting published the widely popular booklet titled ‘Letter on Corpulence Addressed to the Public’ in 1863. In this booklet he explained how he had slimmed down by eating a diet high in fat void of carbs. The Banting diet was used for decades by individuals looking to lose weight.
Low-carb diets may help prevent or improve serious health conditions, such as metabolic syndrome, diabetes, high blood pressure and cardiovascular disease. In fact, almost any diet that helps you shed excess weight can reduce or even reverse risk factors for cardiovascular disease and diabetes. Most weight-loss diets — not just low-carb diets — may improve blood cholesterol or blood sugar levels, at least temporarily.
Over 3 mmol/l is higher than necessary. It will probably achieve neither better nor worse results than being at the 1.5–3 level. Higher numbers can also sometimes mean that you’re not getting enough food (“starvation ketosis”). In people with type 1 diabetes, ketone levels over 3.0 mmol/L can be caused by a severe lack of insulin that requires urgent medical attention.