For a man or an adult woman, 1200 calories is really not a lot of energy. For most people, the daily caloric requirement is from 1600 to 1800 calories, and it is a minimum. In fact, your body spends a lot of calories more than you can imagine. This is called basal metabolism, and that’s what allows you to breathe without thinking. The basal metabolism is also responsible for making the heart beat, functioning your organs like the brain, or to ensure digestion.
Throughout the day your body burns calories and you do not even have to lift a finger to spend hundreds of calories. In most people, the basal metabolism is greater than 1600 calories.
In addition to the basal metabolism, you have to add a few hundred calories because you are inevitably active: you walk, you go to work or in class, you go shopping, you even maybe exercise like running. Most people burn 1800 to 2000 calories a day
So dieting at 1200 calories a day is very draconian and far too hard to bear. You can not go without more than 300 to 400 calories a day without feeling hungry and sometimes extreme fatigue.
A diet at 1200 calories a day is a deficit of 600 to 800 calories each day, which is the double of what a person can support. You will lose weight quickly, but not for very long.
The motivation is not unlimited, and the reason many people fail their weight loss is that they are going way too fast. You have not taken your extra pounds in a few weeks, so why lose them just as quickly?
When you force the body to go faster than the music, it has consequences. The first and most obvious is the yo-yo effect: you will take back all your weight as soon as you stop your diet.
The second consequence is that your motivation will suffer. And when you want to lose weight again, later, you will remember this recovery of the pounds and you will lack motivation.
When you lose weight 3 or 4 times in a row and you keep going back just after when you do the yo-yo with each weight loss, it is discouraging and even depressing. We feel trapped, without solutions, and we begin to believe that losing weight is impossible.