Final answer:
A serving of food must contain less than 3 grams of fat to qualify as low fat. The percent daily value on nutrition labels also can designate a food as 'low' in a nutrient if it is 5% or less, based on a 2,000 calorie diet. The American Heart Association recommends fats should be 30% or less of daily caloric intake.
Step-by-step explanation:
A serving of food to be labeled as low fat must meet specific criteria. To clarify, Option B: < 3 g of fat is generally the correct choice for defining a food as low fat. This means a food item must have less than 3 grams of fat to be considered low fat by regulatory standards. Percent daily value is another aspect that can be considered; a product is regarded as 'low' in a nutrient if it contributes 5% or less to the percent daily value of that nutrient, based on a 2,000 calorie diet.
It's important to note that while a low fat diet can be healthy, fats are still an essential part of the diet. According to health guidelines, such as those from the American Heart Association, fats should provide 30% or less of your total daily calories, with < 10% from saturated fats. This equates to about 65 grams of fat per day on a 2,000 calorie diet, based on average caloric content of fat being 9.1 Calories/g.