If you plan on consuming less than 1200 calories a day, think again! The average person uses almost 1200 calories a day just for things like breathing, digestion and heart beat. At 1200 calories a day, the body is "comfortable" without too much stress and shock.
So, what happens if you do consume less than 1200 calories a day? In a nutshell, you shock your body and will actually possibly gain weight. But, why, you might ask. The body is a very intelligent piece of machinery and it knows what it needs just to exist on a daily basis. Your body knows that it needs fuel (from food and drink) and when it needs it. It also knows, from past experience, that you are going to provide that fuel at certain intervals every day. So, your body happily goes along, using what it needs from the fuel you provide and ridding itself of any excess fuel. (However, keep in mind if you provide too much fuel, the body is going to store it wherever there is a spot: organs, fat cells, you get the picture).
Any drastic interruption (say, less than 1200 calories a day) is going to shock your body into thinking you're going to starve to death. This is called starvation mode and it isn't pretty. Like I said, the body is an intelligent piece of machinery. When it thinks it is going to starve, it holds on (tightly) to every single crumb, ounce and fat gram you do supply and releases very little as waste. Think of it as a sponge. If the sponge is full and water continues to be supplied to it, excess water will drip away because the sponge doesn't need it. A dry sponge will soak up and hold onto every tiny drip of water.
So, what if you slowly drop your calorie intake to under 1200 calories a day? Nope. That won't work either. Your body still requires that amount of calories to survive. Anything less than 1200 calories will throw your body into starvation mode.
But, what about the HCG Diet? Without getting into the diet protocol too much, the HCG diet is designed to burn your stored fat for energy by stimulating your hypothalamus with the human chorionic gonadotropin (a hormone). Therefore, the 500 calories of allowed food per day on this diet is paired with the thousands of calories the hypothalamus burns for energy. Note: I personally do not recommend the HCG diet unless you have over 25 pounds to lose and/or your weight is a contributing factor to disease or serious weight related health risks.
The best way to lose weight is to consume a minimum of 1200 calories a day and I recommend 1500 with some exercise. While you're at it, make those healthy calories like fruits and vegetables with plenty of protein, antioxidants and amino acids.
Trust me, your body will thank you for it and release some of that weight it's been holding on to.