Ok people, we need to talk about calories. I’ll keep this in point form because it’s a huge subject and if I tried to type it all up, I’d fall asleep halfway through.
The truth about calories:
You do need a calorie deficit to burn your body fat reserves. BUT it needs to be under the right conditions or you can negatively affect your Basal Metabolic Rate, making fat-burning much harder.
All calories AREN’T equal. If it was as simple as cutting calories it wouldn’t matter if you had 1200kcal of chocolate cake or 1200kcal of steak a day, the results would be the same. Your body processes the different macronutrients (carbohydrates, proteins and fats) in completely different ways, with completely different outcomes and completely different hormonal responses.
It is IMPOSSIBLE to accurately track calories. Our bodies use some dietary protein and fats for other purposes besides fuel for energy. In addition, our body dumps a lot of excess energy as heat, a metric that varies wildly depending on the energy available. Even one of the scientists who first applied calories to food, Physicist Dr. Johann T. Silbermann, admitted that hormonal responses likely held more sway in practical energy distribution from food.
Calories In and Calories Out AREN’T INDEPENDENT of each other. To a certain degree, if you eat more, you burn more calories but if you eat less, you burn fewer calories. Of course, if you grossly over or under-eat, this won't be true, but if you eat a normal meal and stop when satisfied but not stuffed, you’ll be well within limits.
So, how do you SAFELY have a caloric deficit to lose body fat?
Become fat adapted so you can burn fat as fuel. You have to be capable of using your body fat reserves to replace the calories you won’t be eating as food.
Begin to lower your insulin levels by following the Ketogenic Diet.
As you become FAT ADAPTED you will find you’re not as hungry as you used to be. At this point, follow the Eat when hungry until satisfied, but if not hungry DON’T EAT rule.
As the gaps between your meals widen because you don’t feel hungry, you’ll naturally start Intermittent Fasting. At this point you’ll still be eating all your daily calories but it’ll be from fewer meals with a big gap between them.
As time progresses, you’ll begin consuming less because you’re not hungry. The reason you’re not hungry is that your body fat reserves are now making up the rest of your daily calories.
Unless you first lower your insulin levels (which can take some time if you’re insulin resistant), you shouldn’t force yourself to cut calories to lose weight or (like every other calorie cutting diet out there) you are likely to dangerously lower your Basal Metabolic Rate.
Many people on a carnivore diet regularly eat up to 3500kcal a day (somewhere between OMAD and 20:4) and still lose weight. There are no conclusive studies as yet on why but it’s believed that the extra protein (remember Gluconeogenesis is an “as needed” process, excess protein doesn’t ever convert to glucose) and fat is discarded as waste and due to the very low carbs and insulin of a feasting/fasting carnivorous diet, there isn't enough excess sugar or insulin to convert to new fat.