All three are useful for determining the amount of fat you're eating, but if you want to use just one method, then tracking grams is probably the easiest.

The American Heart Association suggests that healthy adults limit dietary fat to no more than 20 to 35 percent of total daily calories.

To figure out how many fat grams or calories that means for you, start with the number of calories you normally eat or want to eat a day. Multiply that number by the recommended percentages to get the range of fat calories you can eat each day.

Here's an example for total fat based on a 2,000-calorie-a-day diet.

• Multiply 2,000 by 0.20 (20 percent) to get 400 calories.
• Multiply 2,000 by 0.35 (35 percent) to get 700 calories.

How many fat grams is that? There are 9 calories in a gram of fat, so you divide the number of calories by 9.

• Divide 400 calories by 9 (calories a gram) to get about 44 grams of fat.
• Divide 700 calories by 9 (calories a gram) to get about 78 grams of fat.

So if you're on a 2,000-calorie-a-day diet, 400 to 700 calories can come from dietary fat, which translates to between 44 and 78 fat grams a day.

The latest Dietary Guidelines for Americans recommends keeping saturated fat to less than 10 percent of calories a day. For a 2,000-calorie-a-day diet, that's 200 calories or about 22 grams of saturated fat.

Use the Nutrition Facts label to find out how much fat is in the foods you eat. The Nutrition Facts label shows the amount of total fat, saturated fat and trans fat in one serving.

To monitor the fat in your diet, simply add up the fat grams from all the food you ate during the day and compare the total to your target range. Knowing how much fat is in the foods you eat can help you control the fat and calories in your diet, which can help you meet your health and nutrition goals.

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Jan. 30, 2016 See more Expert Answers