If you are so hungry you are getting ill it's no good at all.
The first thing would be to find out how many calories you need based on all sorts of factors. Here's how to do that :
http://www.shapefit.com/basal-metabolic-rate.html
"The Harris-Benedict formula (BMR based on total body weight)
The Harris Benedict equation is a calorie formula using the factors of height, weight, age, and sex to determine basal metabolic rate (BMR). This makes it more accurate than determining calorie needs based on total bodyweight alone. The only variable it does not take into consideration is lean body mass. Therefore, this equation will be very accurate in all but the extremely muscular (will underestimate caloric needs) and the extremely overfat (will overestimate caloric needs).
Men: BMR = 66 + (13.7 X wt in kg) + (5 X ht in cm) - (6.8 X age in years)
Women: BMR = 655 + (9.6 X wt in kg) + (1.8 X ht in cm) - (4.7 X age in years)
Note: 1 inch = 2.54 cm.
1 kilogram = 2.2 lbs.
Example:
You are female
You are 30 yrs old
You are 5' 6 " tall (167.6 cm)
You weigh 120 lbs. (54.5 kilos)
Your BMR = 655 + 523 + 302 - 141 = 1339 calories/day
Now that you know your BMR, you can calculate TDEE by multiplying your BMR by your activity multiplier from the chart below:
Activity Multiplier
Sedentary = BMR X 1.2 (little or no exercise, desk job)
Lightly active = BMR X 1.375 (light exercise/sports 1-3 days/wk)
Mod. active = BMR X 1.55 (moderate exercise/sports 3-5 days/wk)
Very active = BMR X 1.725 (hard exercise/sports 6-7 days/wk)
Extr. active = BMR X 1.9 (hard daily exercise/sports & physical job or 2X day training, i.e marathon, contest etc.)
Example:
Your BMR is 1339 calories per day
Your activity level is moderately active (work out 3-4 times per week)
Your activity factor is 1.55
Your TDEE = 1.55 X 1339 = 2075 calories/day"
...
If I remember well, my BMR was 1,975 calories ...
X 1.725 since I train 6-7 days per week = 3,406 calories per day ... so since I eat only 2,800 to 2,900 calories per day usually, I have a deficit of 500 calories per day, in other words I lose a pound per week at the moment (This is almost spot on !)
Not eating enough can create other problems, slowing down your metabolism because your body is so deprived it's trying to hold on to the fat not knowing when the next meal's going to be !
You should feel a lil' bit hungry most of the time when a meal is coming up soon, not hours before, that's not a good thing. If you are not feeling hungry at all just an hour before a meal, you are eating too much, same thing if you are too hungry all the time - - You have to find the right balance, quantities, timing ... so that you lose weight in a way that is healthy
...
Try changing the quantities and the time of day too (A kitchen scale would be a great tool if you want to be more precise !), if you are feel more hungry in the afternoon you may not have eaten enough for lunch .... so you eat a bit more for lunch next time, having some things extra at that time instead of later.
This takes a lot of trial and error, adjustments, tweaking ...
I changed my system quite a few times ... I am usually not that hungry in the morning so I don't have a lot of calories for breakfast, I save those for later in the day : I have more at lunch and dinner instead. Works well for me.
Losing weight requires a lot of planning, at least that's what I did. You have to think about a lot of details, things you are eating, the way you exercise, all that is important to help you succeed.
Cheers !
Marc