HI Lori and welcome to the forum

Yes, there certainy is such a thing as eating too few calories. Low Carb and Low Calorie doesnt go hand in hand. Quite the opposite, actually. Your body requires a certain amount of food to function; 10 - 12 times your weight is the generaly accepted number. This caloric total is for basal metabolic functioning. It does not take into account exercise or style of living. If you eat too little your body will learn to make do with less and less until eventually you're in starvation mode. Prior to that happening your system will start preparing what it considers to be an impending famine; it will hold on to water and fat. This is a very undesireable situation.

If you've been severely restricing your calories, start upping them slowly. Be sure you're getting your minimum protein requirement (60g is the bare minimum a female needs every day) and do not be afraid to eat fat. You need the fat; it tastes good, it makes you feel full and satiated and there are some fats that can only be found in the foods we eat (these are called Essential Fatty Acids and they are just that, essential).

As for the "low carb" bars; many of them contain hidden carbs. While they may claim to have 2g per bar some have as many as 15g (or more). There is a hidden carb counter located under "low carb tools" at the top of every page. Punch in the numbers from one of your wrappers for more details. Also, check out the article under "low carb tips" about Sugar Alcohols. Very sobering material.

Best of luck to you,
Nat