Not Eating Enough
Drastically reducing your daily calorie intake seems like the simplest and easiest way to lose weight, which is why many people try it. "While calorie deficit is a must for weight loss," registered dietitian Lisa Bunn, director of nutrition at the Genavix Wellness Network, said, "The nuance is that we don't want it to be too much of a deficit."
Without enough food for survival (including our normal daily functions), your body will send signals to conserve calories, slowing down your metabolism. Your body will then choose to get its energy from a more efficient source than our fat stores — our muscles. The American College of Sports Medicine recommends that women should eat at least 1,200 calories per day, and men should eat at least 1,800.