Losing weight can often help stabilize blood pressure and decrease the risk of disease. It must, however, be done safely to avoid complications. Typically, women who restrict their caloric intake to less than 1,200 calories per day may be risking their health. Men should not restrict their caloric intake to less than 1,500 per day. People who are on very low calorie diets may have an increased risk for gallstones and is more commonly seen in women. In addition, very low calorie diets can also have a negative effect on your mental health, contributing to irritability, anxiety and depression.