The amount of sugar one should eat in a day depends mainly on the type of sugar and total calorie intake. For added sugars (those added to foods and drinks), major health organizations recommend:

• For most adult men: no more than 36-38 grams (about 9 teaspoons) of added sugar per day.
• For most adult women: no more than 25-24 grams (about 6 teaspoons) of added sugar per day.

The Dietary Guidelines for Americans suggest keeping added sugars below 10% of total daily calories, which equals about 50 grams (12 teaspoons) for a 2,000-calorie diet. However, more conservative recommendations, including from the World Health Organization and the UK's NHS, advise limiting added or "free" sugars to less than 5% of daily calories, around 25-30 grams (6-7 teaspoons) per day for adults. Natural sugars found in fruits, vegetables, and milk are generally not a concern and are part of a healthy diet. In summary, aiming for no more than 25-38 grams of added sugar daily is recommended, with lower limits beneficial, depending on individual health and caloric needs.