Many dieters are confused when their diet stops working. They carefully planned their meals and upped their time at the gym, only to hit a plateau after losing the first 10 pounds. As your body mass gets smaller, it takes fewer calories to maintain. This means accepting your new weight, or readjusting caloric input and output.
The amount of calories you need to maintain your weight depends on your metabolism, the process your body uses to convert food into energy. Your metabolism is working all the time. Even when you sleep or sit in front of the computer, nutrients are combining with oxygen to keep your heart pumping, your kidneys processing and maintaining a whole lot of other vital functions. Your basal metabolic rate is the amount of calories you need for these basic processes. It accounts for 60 percent to 75 percent of the average person's daily caloric expenditure. Factors affecting your metabolism include body size, sex and age. If you're larger, more muscular, male and younger, your metabolism tends to be higher. Thermogenesis, the body's processing of food, consumes another 10 percent of your daily caloric needs. Physical activity accounts for the rest.
If you are trying to lose weight and you hit a plateau, take a careful look at your diet and exercise. Have the treats been sneaking back in, and the portions gradually expanding? If not, it could be a change in your basal metabolism, also called resting energy expenditure. Your body is always balancing energy in with energy out. Maybe your body used to need 2,200 calories per day to maintain its mass. When you switched to 1,800 calories a day, you were operating on a calorie deficit and thus losing weight. But now you're at a size where 1,800 calories is just right. The American Council on Exercise recommends building more muscle mass through resistance training if you hit a plateau and still want to lose weight. This is because maintaining muscle requires more energy than maintaining fat. The University Health Service at the University of Michigan points out that a plateau could be your body's way of saying you've lost enough weight.
When caloric intake dips too low for too long, the body protects itself by conserving dwindling resources. This happens during times of malnutrition, whether from drought in poorer countries or anorexia in lands of plenty. Resting energy expenditure drops to significantly lower than normal, meaning that maintaining this low body weight requires few calories. This is one of the reasons crash diets are counterproductive for people who want to lose weight.
Just because the body can operate on fewer calories doesn't mean that it likes to, or that it's operating at its best. University of Michigan health center warns that reducing your daily intake below 1,400 calories is dangerous. If your body is forced to look for other fuel sources, it will begin to feed off your muscle. This includes such important muscles as your heart, potentially leading to abnormal heart rhythms. If you're worried about your calorie consumption, especially if you're a young woman who has stopped menstruating, talk to your doctor about your concerns.