Eating too few calories can cause a multitude of health problems, including constipation, fatigue, nausea, diarrhea, headaches and hair loss. Though it is important to eat fewer calories than one burns to facilitate weight loss, doctors recommend that people consume a minimum number of calories every day to minimize risk of these health problems.
The number of calories a person should consume in a day depends on several factors, including gender, weight and age. Diets that allow women to consume between 1,000 and 1,200 calories per day and men to consume between 1,200 and 1,600 calories are most effective, according to the U.S. Department of Health and Human Services.
Though some believe that consuming as few calories as possible is the best way to lose weight, this is not necessarily true. Studies show that those who consume between 1,000 and 1,500 calories per day are more likely to keep weight off long-term than those who consume fewer than 800 calories per day.
Benefits associated with decreasing daily calorie intake typically include healthier cholesterol levels, a lower triglyceride level and a lower risk of heart disease. Those who are overweight or obese and take in between 500 and 1,000 fewer calories per day can lose 1 to 2 pounds per week.