You can't lose weight on 1200 calories a day because you're no longer in a calorie deficit. Your body has adapted to what it's been doing and plateaued. If you start your diet with a 500 calorie deficit per day, your body adapts to this in various way so that over time your energy requirements are reduced.
It is possible that some people might not lose any weight or will need to remain on a restricted calorie diet for a significant time before seeing results. Weight loss will vary between people. For some people, an alternative approach, such as getting more exercise or consuming less sugar, might be a better option.
A 1,200-calorie diet is much too low for most people and can result in negative side effects like dizziness, extreme hunger, nausea, micronutrient deficiencies, fatigue, headaches, and gallstones ( 23 ). Furthermore, a 1,200-calorie diet can set you up for failure if long-term weight loss is your goal.
“And then, of course, everybody's metabolism is slightly different. But the average weight loss that most people see on the 1200 calorie diet is about one to two pounds per week.”
Lummus says that when your body goes into starvation mode, your metabolism slows to a crawl, burning calories as slowly as possible to conserve its energy stores. This is why people who cut their calories too much may reach a plateau and stop losing weight.
Without enough calories, you will quickly experience feelings of fatigue. Because your body doesn't have enough calories to burn and generate energy. You've been losing hair. This is another consequence of a lack of nutrients.
You will not gain weight from eating too few calories.
There are many reasons why it can seem like under-eating can lead to weight gain. But, science has shown over and over again that this isn't physiologically possible.
The amount of food we consume daily has a significant impact on bodily function. Most adults need a minimum of 2000 calories to sustain metabolism, muscle activity, and brain function.
As a general rule, people need a minimum of 1,200 calories daily to stay healthy. People who have a strenuous fitness routine or perform many daily activities need more calories. If you have reduced your calorie intake below 1,200 calories a day, you could be hurting your body in addition to your weight-loss plans.
Your slower metabolism will slow your weight loss, even if you eat the same number of calories that helped you lose weight. When the calories you burn equal the calories you eat, you reach a plateau. To lose more weight, you need to either increase your physical activity or decrease the calories you eat.
Not eating enough
Once you consume fewer than 1000-1200 calories each day, as the body attempts to prevent long term starvation, intense hunger can result.
A Slower Metabolism
Eating too few calories can cause your metabolism to slow down, meaning you won't burn as much fat off when you engage in physical activity. Your body requires energy when you walk, work out, think, breathe, and… well, just about everything!
For example, it would take one 3 to 6 months on average to lose 30 pounds on a 1200 calorie diet. It is based on CDC; one can lose 1 to 2 pounds per week on average.
Muscle is denser than fat.
While one pound of fat weighs the same as one pound of muscle, muscle occupies about 18 percent less space. In addition, muscle burns calories while fat stores them. So, if your weight isn't decreasing but your clothes are starting to fit more loosely, you may be building muscle.
In order to lose at least a pound a week, try to do at least 30 minutes of physical activity on most days, and reduce your daily calorie intake by at least 500 calories. However, calorie intake should not fall below 1,200 a day in women or 1,500 a day in men, except under the supervision of a health professional.
If you're not getting enough calories, chances are you're not getting enough vitamins and minerals either. Nutritional deficiencies may cause a long list of health complications including, but not limited to, anemia, infertility, bone loss, poor dental health and decreased thyroid function.
Losing weight is accompanied by metabolic changes: As you eat less, your body produces less leptin. This hormone, also known as the satiety hormone, makes you feel full and encourages the burning of fat. If you eat less food, your body produces less of it, which can make losing weight harder.
Your Metabolism Will Slow Down to Store Fat
The more you work out or manage your calorie intake to lose weight, the more your metabolism wants to compensate by slowing down to maintain your current weight, this is called metabolic compensation. It kicks in to preserve and store fat for future energy.
You've gained muscle.
And here's an often overlooked fact: Muscle tissue is more dense than fat tissue. So as you gain more muscle and lose fat, you change your overall body composition, which can result in a higher weight, but a smaller figure and better health.