Calorie restriction sounds like the right idea when you want to lose weight. But cutting too many calories isn’t helpful and could backfire.

The Academy of Nutrition and Dietetics explains:

• Restricting too many calories frequently causes malnutrition, which can lead to problems such as osteoporosis.
• You’re likely to gain back lost weight if you restrict calories to a point that’s unsustainable.
• Severely restricting calories puts your body in “starvation mode,” slowing your metabolism and leading to loss of muscle mass.
• Your brain can’t function as well if you’re not giving it the fuel it needs.
• Extreme calorie restriction can lead to gallstones.