Anyone who is trying to cut weight eats less. Which is basic common sense in human physiology since you need to eat fewer calories than you spend to lose weight. You still have to be careful though since cutting too much can hinder your metabolism.
In simple terms, eating too little, for extended periods of time will trigger a few alarms in your body. Its ability to store fat would slowly become a priority. Meaning that it would start storing energy as fat since there is not enough calories coming in. It can also disturb sleep quality, lead to insulin resistance and have a tremendous impact on many hormones in the body.
There is what we call a sweet spot, the goldilocks zone. Let’s say you calculate your basal metabolic rate (BMR) and adjust it with your daily activity and come up with 2500 calories, to lose weight, you would have to cut 250 to 500 calories daily from your diet.