Final answer:
False, losing weight typically reduces the size of fat cells but does not decrease their number. Weight loss involves energy deficit, where stored fat is used, and exercise plays a key role in increasing metabolic rate and energy expenditure.
Step-by-step explanation:
The statement 'When you lose weight, the number of fat cells you have in your body decreases' is false. When you lose weight, the size of the fat cells shrinks, but the number of fat cells typically remains constant. Understanding how the body loses weight involves looking into the body's energy processes and metabolism. The body's energy regulation operates on the principle that if energy expenditure exceeds energy intake, the body will mobilize stored energy, predominantly in the form of fat, to make up for the deficit.
Your basal metabolic rate (BMR) is a critical component of energy expenditure. It represents the rate at which your body uses energy while at rest to maintain vital functions such as breathing and keeping warm. When food intake is reduced significantly, the body compensates by lowering BMR, thereby reducing the rate of weight loss. To counteract this effect, incorporating exercise into a weight loss regimen is beneficial because it not only increases immediate energy expenditure but also raises BMR, contributing to a longer-term increase in total energy output.
However, the physiological response of the body to repetitive dieting can be complex. Subsequent diets may be less effective because the body adjusts to low energy intake by further altering the metabolic rate. This adaptation can make you feel less energetic and slower the weight loss process. It's important to remember that while fat cells can shrink in size during weight loss, they generally do not decrease in number.