One example is the Inuit Indians in northern Alaska, whose diet consists of largely protein and fats throughout much of the year.
In the absence of carbs, the body does two things. First, it will engage in a process called deamination where the NH2 group is stripped form an amino acid to yeld the carbon/hydrogen protion which can be used for fuel. Second, as a by-product of fat breakdown, it will create ketone bodies which can be used, even by tissues such as the CNS, as a fuel source. Thus, proteins and fats can be used to supply the body in the absence of carbs.
When first switching over to a low-carb diet, it may take as much as several weeks for the enzyme pattenrs to change enough to allow optimal usage a fats and amino acids. As long as there are no unique genetic anomalies present in the individual attempting to do this, there shouldn't be a problem.
In the absence of carbs, the body does two things. First, it will engage in a process called deamination where the NH2 group is stripped form an amino acid to yeld the carbon/hydrogen protion which can be used for fuel. Second, as a by-product of fat breakdown, it will create ketone bodies which can be used, even by tissues such as the CNS, as a fuel source. Thus, proteins and fats can be used to supply the body in the absence of carbs.
When first switching over to a low-carb diet, it may take as much as several weeks for the enzyme pattenrs to change enough to allow optimal usage a fats and amino acids. As long as there are no unique genetic anomalies present in the individual attempting to do this, there shouldn't be a problem.

