Why not low carb diets?
Low carb diets are based on large portions of meat and fat products while restricting or completely eliminating carbohydrates.
Many of these diets are based on diets of northern climates where the growing season is extremely short or even non-existant. This would include the traditional eskimo diet and the ice-age paleolithic diet.
These diets are correct that traditional eskimos are extremely healthy and are able to get all nutrients from animal sources. But the eskimo diet relies on animals living on natural diets.
The low carb diet does not transfer well to modern western farming practices, which feed animals very unnatural or processed food. This includes feeding cattle (grass-based animals) high grain diets that cause sickness and obesity. And feeding chickens (omnivores that need animal-based protein such as insects) vegetarian diets.
Low-carb diets posing as based on our paleolithic ancestors focus on a very small, very specific time and geography. They ignore the diets of the oldest tribes in Africa and Australia...
The problem with low-carb diets
The oldest known tribe is the San in Africa, also popularly known as Bushmen or ǃKung. Their diet consists of up to 100 plants with a couple of plant-based staples, the most important being the mongogo nut. They also include meat from hunting, but meat seems to be inconsistent part of thier diet (at least in modern times). Definitely not low carb!
Australian aborigines are one of the oldest tribe known on earth (separating from Africa 55,000-60,000 years ago). In other words, they separated from our distance ancestors before the ice age and idealized low carb diet European mammoth hunters.
They probably didn't have much, if any, contact with other humans until the arrival of white settlers. So they can give an idea of our real paleolithic diet going back to the beginning of our species.
Australian aborigines have been estimated to use up to 900 different species of plants for food (!), though they tended to stick to fewer preferred plants.
Because of the importance of gathering (especially plant-based foods) traditional aboriginal high carb diet was high in good carbohydrates, fiber, and protein. Because of this, their diet was also high in nutrients. While we can never be sure of pre-white contact disease rates, it seems that diseases related to diet were uncommon. This includes cardiovascular disease and diabetes.
These ancient diets are the real paleolithic diets. Not the relatively short-term low carb diet. High in dense nutrients and fiber. Lean protein, overall low in fats, but high in omega 3 fat. Low sugar and salt.
Read more about the paleolithic diet
Low carb is naturally high calories
The emphasis on these diets is protein and fat. The human body cannot digest protein without either carbohydrates or fat. You must choose either carbohydrate or fat for digestion.
The problem is that fat is nine calories of energy per gram, while carbohydrates are only four per gram. And that modern western fatty foods are high in salt and are not the good omega-3 essential fats, but saturated fats.
The key for weight loss while eating carbohydrates is to eat nutrient rich, high fiber, low energy good carbs rather than nutrient deficient, low fiber, high energy bad carbs.
