A common bit of diet advice is that you have to eat enough calories, and that you shouldn’t go below your budget too far (or below your BMR or Base Metabolic Rate). But, this is one of the big differences between low carb and low fat diets.
If you eat low-fat and high-carb, you are basically alternating between spiking up your blood sugar, burning it off, letting it come back down, and then starving your body of necessary resources until the next feeding time. That dance is a happy blend of sugar/starch feeding, treadmill cardio burning, being hungry but distracting/denying it, then eating again, in small quantities so as to get back into starvation mode again quickly.
The low-carb high-fat method doesn’t require you to be hungry, and you don’t have to eat 6 times a day, 2 or 3 times (or even 0 or 1, see Intermittent Fasting) are just fine because you are running on fats, either the fats you ate today or the fats you ate years ago and stored. The important point here is that for low-carb dieters, we very rarely get really hungry, and if we are hungry at all, we eat. There is no denying or distracting necessary. And even if you overeat at one meal, the only side effect is that you’ll be less hungry or go longer until your next meal, so it is both forgiving and self-regulating. (Throw in ketosis as “bonus points” – that translates to extra fat converted to calories that can often end up in urine, just peeing out calories. )
So, once you are fat-adapted and you are truly able to trust your hunger signals, then you can use your own hunger as your guide and you don’t have to worry about the lower-limits… those are the safety rails put there for the benefit of those who depend on denying hunger signals for their plans to succeed… If you are not sure whether your hunger signals are working, try fasting a bit to test them :)
Finally the great thing about low-carb is that you don’t have to jump in the deep end. You can get most of the benefits of not being hungry as often, being able to eat when you’re hungry, etc… just by cutting some of the carbs. 100 grams is a reasonable middle-step. You won’t get into ketosis, so no bonus points, but you’ll probably notice that you’re more in control, your plans just work better, and you may even be happier. Then, you can decide if you want to go lower, or keep it there for a while. This seems to be a turning point for a lot of people… it is hard for 2-4 weeks and then gets easier, within 6 or 8 weeks people usually find it’s so much easier than what they were doing before, they won’t go back.
More great information here: The Context of Calories on Mark’s Daily Apple.