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.
“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.
Many studies have shown that following low calorie diets, including 1,200-calorie diets, can promote weight loss. For example, a study in 2,093 people with obesity demonstrated that a medically supervised 1,200-calorie meal replacement diet resulted in an average fat loss of 4.7% over 12 months ( 6 ).
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.
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.
You're eating too much during your eating window.
“If you end up consuming the same number of calories (or more) during your eating windows as before you started intermittent fasting, then you won't lose 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.
Unintentional weight gain occurs when you put on weight without increasing your consumption of food or liquid and without decreasing your activity. This occurs when you're not trying to gain weight. It's often due to fluid retention, abnormal growths, constipation, or pregnancy.
As you can see, individual weight-loss experiences and time frames can vary heavily. However, most people who start dieting by cutting out a certain amount of calories each day will see results within one to two weeks, even if it's just one pound lost.
The first stage of weight loss is when you tend to lose the most weight and begin to notice changes in your appearance and how your clothes fit. It usually happens within the first 4–6 weeks ( 1 ). Most of the weight loss in this stage comes from carb stores, protein, and water — and to a lesser extent, body fat.
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.
It is commonly said that if you eat too few calories, your metabolism will slow down to a point where you no longer lose weight. Part of this is true: as you lose weight your energy expenditure does drop. However, consuming too few calories cannot and will not cause you to gain weight. This is simply impossible.
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 humans. Ordinarily, the body responds to reduced energy intake by burning fat reserves and consuming muscle and other tissues. Specifically, the body burns fat after first exhausting the contents of the digestive tract along with glycogen reserves stored in liver cells and after significant protein loss.
If you drastically slash calories and are eating a very low-calorie diet (Think: less than 1,000 calories for women and less than 1,200 calories for men), “starvation mode” can actually be starvation. Starvation from chronic undereating can be counterproductive to weight loss and dangerous to your health.
Calorie intake: Your Eating too much or Not Enough
A HUGE factor that plays into your intermittent fasting results is how much you are eating. It can go both ways, eating too much or not eating enough - both have negative effects on your results and could be why you aren't seeing results with intermittent fasting.
YOU'RE NOT EATING ENOUGH DURING YOUR WINDOW
You'll be so hungry, you may start eating and not stop. As well, the body stores food to protect itself. Your body will sense the need to stock up on reserves and may store those extra pounds as fat instead of lean 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.
For a person to lose 1 lb of fat in a week, they would need a deficit of 3,500 calories, or 500 calories per day, over that time. To lose 2 lb, a person would need a deficit of about 7,000 calories. However, it is not advisable for a calorie deficit to exceed 7,000 calories per week.