That may be your problem, right there. Two things are required for the body to be willing and able to give up its store of excess fat: first, we have to eat so little carbohydrate that our insulin drops low enough to stop telling our fat cells to hoard fat. Second, we need to give our body enough calories to convince it that letting go of excess stored fat is safe (under famine conditions, the body hangs on to all its resources for as long as it can).
As long as your carbohydrate intake is under 20 g/day, you are fulfilling the first condition (many people can actually eat more carbohydrate than that, but this is a good level at which to start, since it pretty much guarantees results, if your metabolism is not too badly damaged). The surest way to meet the second condition is to eat plenty of fat.
Carbohydrate stimulates insulin secretion at a high rate, so it is best avoided (our body doesn’t need it, either). Protein stimulates insulin secretion at about half the rate at which carbohydrate does, but we must have protein in order to be healthy (its effect on insulin is much less on a low-carb diet, too). Fat has a negligible effect on insulin (especially when compared with carbohydrate), so it is the safest source of calories to replace the calories you are no longer getting from carbohydrate.
The easiest and most accurate way to be sure you are getting enough calories for your body to be willing to consume its excess fat is to eat to satiety. Avoid consulting a macro calculator. As long as you are keeping your carbohydrate low, you can safely eat as much protein and fat as it takes to satisfy your hunger. For most people hunger is satisfied long before they reach the point of filling up their bellies (as most of us had to do as sugar-burners), so keto is an all-you-want diet, not an all-you-can-eat diet. With insulin low, your hormones should be controlling your appetite, and eating to satiety will give your body enough food to convince it to use some of that extra stored fat as well as the fat you are eating.
