Here’s a great post by Dr. Michael Eades on how you lose weight and why fat loss stalls on a low carb diet.
First, Dr Eades describes the weight loss process…
Let’s look at what happens when we cut carbohydrates in the diet. First we don’t get enough carbs to replenish our blood sugar, so the body has to convert protein to glucose to make up the difference. The signal to do this comes from a rising level of glucagon, a hormone made in and released by the pancreas. In order for glucagon to do its job, the level of insulin in the blood has to go down, which it does. A low level of insulin and a high level of glucagon send a signal to the fat cells telling them to release their fat. You can think of it as opening the doors to the fat cells so that fat can easily get out. The body burns this fat for energy. As the body burns more, the fat cells release more. When the fat cells dump their fat, they become smaller. When your fat cells or adipose tissue becomes smaller, you become smaller. And you lose weight.
Then he explains that you must create a caloric deficit…
Although the lowered insulin and elevated glucagon open the doors to the fat cells allowing fat to come out to be burned, the fat comes out only if it’s needed. If you are meeting all your body’s energy needs with the food you eat, the body doesn’t need the fat in the fat cells. On a low-carb diet your body burns fat for energy. But it doesn’t care where this fat comes from; it can come from the diet or it can come from the fat cells or it can come from both. If you are consuming enough fat to meet all your body’s requirements, your body won’t go after the fat in the fat cells no matter how severely you restrict your carbs. You will burn dietary fat only and no body fat. And you won’t lose weight. It’s that simple.
I’ve seen so many clients lose weight this way that I have no doubt that it works, for anyone, at any age. But you must create a caloric deficit and lower carbs; the only reason that progress stalls is, either you start eating too many carbs or too many calories.
I like to use a food diary also. That way if you hit a plateau, you can see exactly where you went wrong, make the necessary corrections, and continue on with the fat loss.