Eating too few calories

A significant slowdown in metabolism can result from eating too few calories. Although a calorie deficit is necessary for weight loss, cutting your calorie intake too much can be harmful. When you drastically cut back on calories, your body senses that there is less food available and slows down how quickly it burns calories.

Consuming less than 1,000 calories per day might significantly affect your metabolic rate, according to controlled research on lean and overweight people. The majority of research calculates the number of calories burnt while at rest, or the resting metabolic rate. In one study, obese women who consumed 420 calories per day for 4-6 months saw a significant reduction in their resting metabolic rates. Furthermore, their resting metabolic rates continued to be significantly lower than before the diet, even after they doubled their calorie intake over the course of the following five weeks. Calorie restriction can still impede metabolism even when it is moderate. In a 4-day trial including 32 participants, those who consumed 1,114 calories per day saw a slower resting metabolic rate than those who consumed 1,462 calories.